Stroke

Extended follow-up of the PRAGUE-17 trial suggests left atrial appendage closure (LAAC) remains noninferior to direct-acting oral anticoagulants (DOACs) with regard to major cardiovascular and neurologic events in high-risk patients with atrial fibrillation.

At a median follow-up of 3.5 years, the annualized rate of the primary outcome – a composite of stroke, transient ischemic attack (TIA), systemic embolism, cardiovascular death, clinically relevant bleeding, or significant procedure- or device-related complications – was 8.6% in patients who underwent LAAC and 11.9% in those managed with DOACs (P value for noninferiority = .006).

The study was not powered to assess the individual components, but most were similar between the LAAC and DOAC groups, including cardiovascular death (20 vs. 30 events) and all stroke/TIA (16 vs. 18 events).

Nonprocedural clinically relevant bleeding was lower with LAAC (23 vs. 40 events; annualized rate, 3.4% vs. 5.9%; P = .039), said Pavel Osmancik, MD, PhD, Charles University and University Hospital Kralovske Vinohrady, both in Prague.

The data were presented at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando and sponsored by the Cardiovascular Research Foundation, and was published simultaneously in the Journal of the American College of Cardiology.

The results are generally in line with those reported in 2020 with an average follow-up of 20 months, when the annualized primary event rate was 11% with LAAC and 13% with DOACs, also known as novel OACs (NOACs).

The trial randomly assigned 415 patients to LAAC with the Amulet (Abbott Vascular) or Watchman/Watchman FLX devices (Boston Scientific) or to rivaroxaban, dabigatran, or preferably apixaban (96%). The modified intention-to-treat analysis included 201 patients in each group, with follow-up extending to 4.3 years in the LAAC group and 4.2 years in the DOAC group.

Dr. Osmancik said the trial enrolled a very-high-risk atrial fibrillation cohort, citing a CHA2DS2-VASc score of 4.7 in both groups and a HAS-BLED score of 3.0-3.1. More than half of the LAAC group (54.2%) and 47.3% of the DOAC group had a history of bleeding or bleeding predisposition.

During a discussion of the results, the panel questioned whether the continuing divergence of the primary event curves at 4 years was potentially related to the effect of noncompliance to the NOACs over time.

Dr. Osmancik replied: “We didn’t do any medication look among the patients, but I don’t think that the number of patients who stopped the NOAC treatment was too high because the rate of strokes was very similar to that in the NOAC trials.”

He reported that 26 patients in the DOAC group permanently stopped their DOAC during follow-up; 15 (58%) because of clinically relevant bleeding, and 13 crossed over to LAAC. Of the 13 patients, 12 cases were successful with dual antiplatelet therapy for 3 months.

In the LAAC group, 17 patients started a DOAC during follow-up. Of these, three (18%) initiated DOAC treatment because of device-related thrombus (DRT) on transesophageal echocardiography, three (18%) because of a peridevice leak (PDL), and five (29%) because of a stroke/TIA.

“Given the observed trend of significantly increased nonprocedural clinically relevant bleeding in the NOAC arm, it is likely that late bleeding events will increasingly favor LAAC over time,” Faisal Merchant, MD, Emory University, Atlanta, wrote in an accompanying editorial.

NOACs, he noted, have important indications beyond prevention of left atrial appendage thrombi, including prevention of non-LAA sources of stroke/systemic embolism (SSE) and treatment of venous thromboembolism. “If significant numbers of patients treated with LAAC end up on anticoagulation in the long run, the benefits of LAAC are likely to be attenuated.”

Although PRAGUE-17 provides some insights into the longer-term indications for resuming anticoagulation in patients previously treated with LAAC, Dr. Merchant said the trial is a “real missed opportunity” in terms of understanding late device-associated risks. Unfortunately, two-thirds of the follow-up transesophageal echocardiograms were canceled because of the COVID-19 pandemic.

“Although the incidence of late DRT and PDL isn’t known, the longer-term PRAGUE-17 data are helpful in demonstrating that rates of SSE remain similar in the LAAC and NOAC groups over time, without any obvious signal of late ischemic events in the LAAC group,” he wrote.

The editorialist also called attention to the “often overlooked” issue of aspirin adherence in long-term medical therapy. Although patients treated with LAAC typically remain on aspirin indefinitely, the percentage who discontinue long-term aspirin is not well described and is not reported in PRAGUE-17. In the AVERROES trial, comparing aspirin with apixaban in patients with atrial fibrillation, however, 20.5% of patients permanently discontinued aspirin at 2 years, compared with only 17.9% on apixaban.

“It is plausible that discontinuation of aspirin may contribute to late ischemic events in patients treated with LAAC, potentially by increasing the risk of late DRT or through other mechanisms,” Dr. Merchant wrote. “Adherence to, and the impact of, long-term antiplatelet therapy should be a focus of future LAAC studies.”

The study was funded by a research grant from the Ministry of Health, Czech Republic. Dr. Osmancik reported occasional speaking honoraria from Bayer and Abbott. Dr. Merchant disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Extended follow-up of the PRAGUE-17 trial suggests left atrial appendage closure (LAAC) remains noninferior to direct-acting oral anticoagulants (DOACs) with regard to major cardiovascular and neurologic events in high-risk patients with atrial fibrillation.

At a median follow-up of 3.5 years, the annualized rate of the primary outcome – a composite of stroke, transient ischemic attack (TIA), systemic embolism, cardiovascular death, clinically relevant bleeding, or significant procedure- or device-related complications – was 8.6% in patients who underwent LAAC and 11.9% in those managed with DOACs (P value for noninferiority = .006).

The study was not powered to assess the individual components, but most were similar between the LAAC and DOAC groups, including cardiovascular death (20 vs. 30 events) and all stroke/TIA (16 vs. 18 events).

Nonprocedural clinically relevant bleeding was lower with LAAC (23 vs. 40 events; annualized rate, 3.4% vs. 5.9%; P = .039), said Pavel Osmancik, MD, PhD, Charles University and University Hospital Kralovske Vinohrady, both in Prague.

The data were presented at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando and sponsored by the Cardiovascular Research Foundation, and was published simultaneously in the Journal of the American College of Cardiology.

The results are generally in line with those reported in 2020 with an average follow-up of 20 months, when the annualized primary event rate was 11% with LAAC and 13% with DOACs, also known as novel OACs (NOACs).

The trial randomly assigned 415 patients to LAAC with the Amulet (Abbott Vascular) or Watchman/Watchman FLX devices (Boston Scientific) or to rivaroxaban, dabigatran, or preferably apixaban (96%). The modified intention-to-treat analysis included 201 patients in each group, with follow-up extending to 4.3 years in the LAAC group and 4.2 years in the DOAC group.

Dr. Osmancik said the trial enrolled a very-high-risk atrial fibrillation cohort, citing a CHA2DS2-VASc score of 4.7 in both groups and a HAS-BLED score of 3.0-3.1. More than half of the LAAC group (54.2%) and 47.3% of the DOAC group had a history of bleeding or bleeding predisposition.

During a discussion of the results, the panel questioned whether the continuing divergence of the primary event curves at 4 years was potentially related to the effect of noncompliance to the NOACs over time.

Dr. Osmancik replied: “We didn’t do any medication look among the patients, but I don’t think that the number of patients who stopped the NOAC treatment was too high because the rate of strokes was very similar to that in the NOAC trials.”

He reported that 26 patients in the DOAC group permanently stopped their DOAC during follow-up; 15 (58%) because of clinically relevant bleeding, and 13 crossed over to LAAC. Of the 13 patients, 12 cases were successful with dual antiplatelet therapy for 3 months.

In the LAAC group, 17 patients started a DOAC during follow-up. Of these, three (18%) initiated DOAC treatment because of device-related thrombus (DRT) on transesophageal echocardiography, three (18%) because of a peridevice leak (PDL), and five (29%) because of a stroke/TIA.

“Given the observed trend of significantly increased nonprocedural clinically relevant bleeding in the NOAC arm, it is likely that late bleeding events will increasingly favor LAAC over time,” Faisal Merchant, MD, Emory University, Atlanta, wrote in an accompanying editorial.

NOACs, he noted, have important indications beyond prevention of left atrial appendage thrombi, including prevention of non-LAA sources of stroke/systemic embolism (SSE) and treatment of venous thromboembolism. “If significant numbers of patients treated with LAAC end up on anticoagulation in the long run, the benefits of LAAC are likely to be attenuated.”

Although PRAGUE-17 provides some insights into the longer-term indications for resuming anticoagulation in patients previously treated with LAAC, Dr. Merchant said the trial is a “real missed opportunity” in terms of understanding late device-associated risks. Unfortunately, two-thirds of the follow-up transesophageal echocardiograms were canceled because of the COVID-19 pandemic.

“Although the incidence of late DRT and PDL isn’t known, the longer-term PRAGUE-17 data are helpful in demonstrating that rates of SSE remain similar in the LAAC and NOAC groups over time, without any obvious signal of late ischemic events in the LAAC group,” he wrote.

The editorialist also called attention to the “often overlooked” issue of aspirin adherence in long-term medical therapy. Although patients treated with LAAC typically remain on aspirin indefinitely, the percentage who discontinue long-term aspirin is not well described and is not reported in PRAGUE-17. In the AVERROES trial, comparing aspirin with apixaban in patients with atrial fibrillation, however, 20.5% of patients permanently discontinued aspirin at 2 years, compared with only 17.9% on apixaban.

“It is plausible that discontinuation of aspirin may contribute to late ischemic events in patients treated with LAAC, potentially by increasing the risk of late DRT or through other mechanisms,” Dr. Merchant wrote. “Adherence to, and the impact of, long-term antiplatelet therapy should be a focus of future LAAC studies.”

The study was funded by a research grant from the Ministry of Health, Czech Republic. Dr. Osmancik reported occasional speaking honoraria from Bayer and Abbott. Dr. Merchant disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Extended follow-up of the PRAGUE-17 trial suggests left atrial appendage closure (LAAC) remains noninferior to direct-acting oral anticoagulants (DOACs) with regard to major cardiovascular and neurologic events in high-risk patients with atrial fibrillation.

At a median follow-up of 3.5 years, the annualized rate of the primary outcome – a composite of stroke, transient ischemic attack (TIA), systemic embolism, cardiovascular death, clinically relevant bleeding, or significant procedure- or device-related complications – was 8.6% in patients who underwent LAAC and 11.9% in those managed with DOACs (P value for noninferiority = .006).

The study was not powered to assess the individual components, but most were similar between the LAAC and DOAC groups, including cardiovascular death (20 vs. 30 events) and all stroke/TIA (16 vs. 18 events).

Nonprocedural clinically relevant bleeding was lower with LAAC (23 vs. 40 events; annualized rate, 3.4% vs. 5.9%; P = .039), said Pavel Osmancik, MD, PhD, Charles University and University Hospital Kralovske Vinohrady, both in Prague.

The data were presented at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando and sponsored by the Cardiovascular Research Foundation, and was published simultaneously in the Journal of the American College of Cardiology.

The results are generally in line with those reported in 2020 with an average follow-up of 20 months, when the annualized primary event rate was 11% with LAAC and 13% with DOACs, also known as novel OACs (NOACs).

The trial randomly assigned 415 patients to LAAC with the Amulet (Abbott Vascular) or Watchman/Watchman FLX devices (Boston Scientific) or to rivaroxaban, dabigatran, or preferably apixaban (96%). The modified intention-to-treat analysis included 201 patients in each group, with follow-up extending to 4.3 years in the LAAC group and 4.2 years in the DOAC group.

Dr. Osmancik said the trial enrolled a very-high-risk atrial fibrillation cohort, citing a CHA2DS2-VASc score of 4.7 in both groups and a HAS-BLED score of 3.0-3.1. More than half of the LAAC group (54.2%) and 47.3% of the DOAC group had a history of bleeding or bleeding predisposition.

During a discussion of the results, the panel questioned whether the continuing divergence of the primary event curves at 4 years was potentially related to the effect of noncompliance to the NOACs over time.

Dr. Osmancik replied: “We didn’t do any medication look among the patients, but I don’t think that the number of patients who stopped the NOAC treatment was too high because the rate of strokes was very similar to that in the NOAC trials.”

He reported that 26 patients in the DOAC group permanently stopped their DOAC during follow-up; 15 (58%) because of clinically relevant bleeding, and 13 crossed over to LAAC. Of the 13 patients, 12 cases were successful with dual antiplatelet therapy for 3 months.

In the LAAC group, 17 patients started a DOAC during follow-up. Of these, three (18%) initiated DOAC treatment because of device-related thrombus (DRT) on transesophageal echocardiography, three (18%) because of a peridevice leak (PDL), and five (29%) because of a stroke/TIA.

“Given the observed trend of significantly increased nonprocedural clinically relevant bleeding in the NOAC arm, it is likely that late bleeding events will increasingly favor LAAC over time,” Faisal Merchant, MD, Emory University, Atlanta, wrote in an accompanying editorial.

NOACs, he noted, have important indications beyond prevention of left atrial appendage thrombi, including prevention of non-LAA sources of stroke/systemic embolism (SSE) and treatment of venous thromboembolism. “If significant numbers of patients treated with LAAC end up on anticoagulation in the long run, the benefits of LAAC are likely to be attenuated.”

Although PRAGUE-17 provides some insights into the longer-term indications for resuming anticoagulation in patients previously treated with LAAC, Dr. Merchant said the trial is a “real missed opportunity” in terms of understanding late device-associated risks. Unfortunately, two-thirds of the follow-up transesophageal echocardiograms were canceled because of the COVID-19 pandemic.

“Although the incidence of late DRT and PDL isn’t known, the longer-term PRAGUE-17 data are helpful in demonstrating that rates of SSE remain similar in the LAAC and NOAC groups over time, without any obvious signal of late ischemic events in the LAAC group,” he wrote.

The editorialist also called attention to the “often overlooked” issue of aspirin adherence in long-term medical therapy. Although patients treated with LAAC typically remain on aspirin indefinitely, the percentage who discontinue long-term aspirin is not well described and is not reported in PRAGUE-17. In the AVERROES trial, comparing aspirin with apixaban in patients with atrial fibrillation, however, 20.5% of patients permanently discontinued aspirin at 2 years, compared with only 17.9% on apixaban.

“It is plausible that discontinuation of aspirin may contribute to late ischemic events in patients treated with LAAC, potentially by increasing the risk of late DRT or through other mechanisms,” Dr. Merchant wrote. “Adherence to, and the impact of, long-term antiplatelet therapy should be a focus of future LAAC studies.”

The study was funded by a research grant from the Ministry of Health, Czech Republic. Dr. Osmancik reported occasional speaking honoraria from Bayer and Abbott. Dr. Merchant disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Higher intake of vegetable fats from foods such as olive oil and nuts is associated with a lower risk for stroke, whereas people who eat more animal fats, especially processed red meats, may have a higher stroke risk, observational findings suggest.

camij/thinkstockphotos.com

In a study of more than 117,000 health professionals who were followed for 27 years, those whose diet was in the highest quintile for intake of vegetable fat had a 12% lower risk for stroke, compared with those who consumed the least amount of vegetable fats.

Conversely, having the highest intake of animal fat from nondairy sources was associated with a 16% increased risk of stroke.

Fenglei Wang, PhD, presented these results at the American Heart Association scientific sessions.

“Our findings support the Dietary Guidelines for Americans and dietary recommendations by AHA,” Dr. Wang, a postdoctoral fellow in the department of nutrition at Harvard University’s T.H. Chan School of Public Health in Boston, told this news organization.

“The main sources of vegetable fat have a large overlap with polyunsaturated fat, such as vegetable oils, nuts, walnuts, and peanut butter,” Dr. Wang noted, adding that fish, especially fatty fish, is a main source of polyunsaturated fat and is recommended for cardiovascular health.

“We would recommend that people reduce consumption of red and processed meat, minimize fatty parts of unprocessed meat if consumed, and replace lard or tallow (beef fat) with nontropical vegetable oils, such as olive oil, corn, or soybean oils in cooking, to lower their stroke risk,” she said.

Moreover, although the results from this study of dietary fat are informative, Dr. Wang continued, “there are other dietary factors (fruits, vegetables, salt, alcohol, et cetera), and lifestyle factors (physical activity, smoking, et cetera), that are associated with stroke risk and worthy of attention as well.”

“Many processed meats are high in salt and saturated fat, and low in vegetable fat,” Alice H. Lichtenstein, DSc, an AHA spokesperson who was not involved with this research, noted in a press release.

“Research shows that replacing processed meat with other protein sources, particularly plant sources, is associated with lower death rates,” added Dr. Lichtenstein, the Stanley N. Gershoff professor of nutrition science and policy at Tufts University in Boston, and lead author of the AHA’s 2021 scientific statement, Dietary Guidance to Improve Cardiovascular Health.

“Key features of a heart-healthy diet pattern,” she summarized, “are to balance calorie intake with calorie needs to achieve and maintain a healthy weight; choose whole grains, lean and plant-based protein, and a variety of fruits and vegetables; limit salt, sugar, animal fat, processed foods, and alcohol; and apply this guidance regardless of where the food is prepared or consumed.”
 

Replace processed meat with plant proteins

The focus on stroke in this study “is important” because, traditionally, studies of diet and cardiovascular health have focused on coronary heart disease, Andrew Mente, PhD, who also was not involved in this research, said in an email to this news organization.

“Overall, the take-home message from the study is that replacing processed meat with plant sources of protein in the diet is probably beneficial,” Dr. Mente, associate professor, health research methods, evidence, and impact, Faculty of Health Sciences, McMaster University, Hamilton, Ont., said.

The finding that people who ate the most vegetable fat had a modest 12% lower risk of stroke than those who ate the least vegetable fat “points to protective effects of foods like seeds, nuts, vegetables, and olive oil, which has been shown previously,” he continued.

The highest quintile of total red meat intake was associated with an 8% higher risk for stroke, but this was driven mainly by processed red meat (which was associated with a 12% higher risk for stroke). These findings are “generally consistent with cohort studies showing that processed meat, as with most highly processed foods for that matter, are associated with an increased risk of cardiovascular events,” Dr. Mente noted.

“Surprisingly, dairy products (such as cheese, butter, or milk) in the study were not connected with the risk of stroke,” he added. This finding differs from results of meta-analyses of multiple cohort studies of dairy intake and stroke and the recent large international PURE study, which showed that dairy intake was associated with a lower risk for stroke.

“What is needed to move the field forward,” according to Dr. Mente, “is to employ new methods that use cutting-edge technology to study nutritional biomarkers and health outcomes.”

“When dealing with modest associations as usually encountered in nutrition, it is a challenge to make causal connections based on dietary questionnaires, which are fraught with measurement error,” he added. “The use of novel methods is where the field is headed.”
 

Total dietary fat, different types, and different food sources

Dr. Wang and colleagues investigated how total dietary fat, different types of fat, and fats from different foods were associated with incident stroke in 73,867 women in the 1984-2016 Nurses’ Health Study and 43,269 men who participated in the 1986-2016 Health Professionals Follow-up Study.

The participants had an average age of 50 years, 63% were women, and 97% were White. They replied to food-frequency questionnaires every 4 years.

Total red meat included beef, pork, or lamb (as a main dish or in sandwiches or mixed dishes) as well as processed red meats (such as bacon, sausage, bologna, hot dogs, and salami).

Animal fat sources included meat, beef tallow, lard, and full-fat dairy products, such as full-fat milk and cheese.

The median percentage of total daily calories from different sources of fat ranged from 10% to 20% for vegetable fat, 3% to 10% for dairy fat, and 7% to 17% for nondairy animal fat (for lowest to highest quintiles).

The median percentage of total daily calories from different types of fat ranged from 5% to 8% for polyunsaturated fat, 4% to 7% for n-6 polyunsaturated fat, 9% to 15% for monounsaturated fat, 8% to 14% for saturated fat, and 1% to 2% for trans fat.

During follow-up, there were 6,189 incident strokes, including 2,967 ischemic strokes and 814 hemorrhagic strokes.

The researchers found that intake in the highest quintile of vegetable fat was associated with a lower risk for total stroke, compared with the lowest quintile (hazard ratio, 0.88; 95% confidence interval, 0.81-0.96; P for trend < .001).

Similarly, the highest intake of polyunsaturated fat was also associated with lower total stroke (HR, 0.88; 95% CI, 0.80-0.96; P for trend = .002). 

Highest intake of nondairy animal fat, however, was associated with an increased risk for total stroke (HR, 1.16; 95% CI, 1.05-1.29; P for trend < .001). They observed “similar associations” for ischemic stroke, but the only positive association for nondairy animal fat was with hemorrhagic stroke, the abstract notes.   

The risk for stroke was lower by 9% per serving per day for vegetable oil but increased by 8% and 12%, respectively, per serving of total red meat or processed red meat.

The association for vegetable oil was attenuated after adjustment for vegetable fat or polyunsaturated fat, whereas adjustment for nondairy animal fat rendered the association for total red meat and processed red meat nonsignificant. 

The study was funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Dr. Wang has no relevant financial disclosures. Dr. Mente has received research funding from the Dairy Farmers of Canada and the National Dairy Council to analyze data on dairy consumption and health outcomes in the PURE study, which is funded by the Population Health Research Institute, Hamilton Health Sciences Research Institute, and more than 70 other sources (government and pharmaceutical).

A version of this article first appeared on Medscape.com.

Higher intake of vegetable fats from foods such as olive oil and nuts is associated with a lower risk for stroke, whereas people who eat more animal fats, especially processed red meats, may have a higher stroke risk, observational findings suggest.

camij/thinkstockphotos.com

In a study of more than 117,000 health professionals who were followed for 27 years, those whose diet was in the highest quintile for intake of vegetable fat had a 12% lower risk for stroke, compared with those who consumed the least amount of vegetable fats.

Conversely, having the highest intake of animal fat from nondairy sources was associated with a 16% increased risk of stroke.

Fenglei Wang, PhD, presented these results at the American Heart Association scientific sessions.

“Our findings support the Dietary Guidelines for Americans and dietary recommendations by AHA,” Dr. Wang, a postdoctoral fellow in the department of nutrition at Harvard University’s T.H. Chan School of Public Health in Boston, told this news organization.

“The main sources of vegetable fat have a large overlap with polyunsaturated fat, such as vegetable oils, nuts, walnuts, and peanut butter,” Dr. Wang noted, adding that fish, especially fatty fish, is a main source of polyunsaturated fat and is recommended for cardiovascular health.

“We would recommend that people reduce consumption of red and processed meat, minimize fatty parts of unprocessed meat if consumed, and replace lard or tallow (beef fat) with nontropical vegetable oils, such as olive oil, corn, or soybean oils in cooking, to lower their stroke risk,” she said.

Moreover, although the results from this study of dietary fat are informative, Dr. Wang continued, “there are other dietary factors (fruits, vegetables, salt, alcohol, et cetera), and lifestyle factors (physical activity, smoking, et cetera), that are associated with stroke risk and worthy of attention as well.”

“Many processed meats are high in salt and saturated fat, and low in vegetable fat,” Alice H. Lichtenstein, DSc, an AHA spokesperson who was not involved with this research, noted in a press release.

“Research shows that replacing processed meat with other protein sources, particularly plant sources, is associated with lower death rates,” added Dr. Lichtenstein, the Stanley N. Gershoff professor of nutrition science and policy at Tufts University in Boston, and lead author of the AHA’s 2021 scientific statement, Dietary Guidance to Improve Cardiovascular Health.

“Key features of a heart-healthy diet pattern,” she summarized, “are to balance calorie intake with calorie needs to achieve and maintain a healthy weight; choose whole grains, lean and plant-based protein, and a variety of fruits and vegetables; limit salt, sugar, animal fat, processed foods, and alcohol; and apply this guidance regardless of where the food is prepared or consumed.”
 

Replace processed meat with plant proteins

The focus on stroke in this study “is important” because, traditionally, studies of diet and cardiovascular health have focused on coronary heart disease, Andrew Mente, PhD, who also was not involved in this research, said in an email to this news organization.

“Overall, the take-home message from the study is that replacing processed meat with plant sources of protein in the diet is probably beneficial,” Dr. Mente, associate professor, health research methods, evidence, and impact, Faculty of Health Sciences, McMaster University, Hamilton, Ont., said.

The finding that people who ate the most vegetable fat had a modest 12% lower risk of stroke than those who ate the least vegetable fat “points to protective effects of foods like seeds, nuts, vegetables, and olive oil, which has been shown previously,” he continued.

The highest quintile of total red meat intake was associated with an 8% higher risk for stroke, but this was driven mainly by processed red meat (which was associated with a 12% higher risk for stroke). These findings are “generally consistent with cohort studies showing that processed meat, as with most highly processed foods for that matter, are associated with an increased risk of cardiovascular events,” Dr. Mente noted.

“Surprisingly, dairy products (such as cheese, butter, or milk) in the study were not connected with the risk of stroke,” he added. This finding differs from results of meta-analyses of multiple cohort studies of dairy intake and stroke and the recent large international PURE study, which showed that dairy intake was associated with a lower risk for stroke.

“What is needed to move the field forward,” according to Dr. Mente, “is to employ new methods that use cutting-edge technology to study nutritional biomarkers and health outcomes.”

“When dealing with modest associations as usually encountered in nutrition, it is a challenge to make causal connections based on dietary questionnaires, which are fraught with measurement error,” he added. “The use of novel methods is where the field is headed.”
 

Total dietary fat, different types, and different food sources

Dr. Wang and colleagues investigated how total dietary fat, different types of fat, and fats from different foods were associated with incident stroke in 73,867 women in the 1984-2016 Nurses’ Health Study and 43,269 men who participated in the 1986-2016 Health Professionals Follow-up Study.

The participants had an average age of 50 years, 63% were women, and 97% were White. They replied to food-frequency questionnaires every 4 years.

Total red meat included beef, pork, or lamb (as a main dish or in sandwiches or mixed dishes) as well as processed red meats (such as bacon, sausage, bologna, hot dogs, and salami).

Animal fat sources included meat, beef tallow, lard, and full-fat dairy products, such as full-fat milk and cheese.

The median percentage of total daily calories from different sources of fat ranged from 10% to 20% for vegetable fat, 3% to 10% for dairy fat, and 7% to 17% for nondairy animal fat (for lowest to highest quintiles).

The median percentage of total daily calories from different types of fat ranged from 5% to 8% for polyunsaturated fat, 4% to 7% for n-6 polyunsaturated fat, 9% to 15% for monounsaturated fat, 8% to 14% for saturated fat, and 1% to 2% for trans fat.

During follow-up, there were 6,189 incident strokes, including 2,967 ischemic strokes and 814 hemorrhagic strokes.

The researchers found that intake in the highest quintile of vegetable fat was associated with a lower risk for total stroke, compared with the lowest quintile (hazard ratio, 0.88; 95% confidence interval, 0.81-0.96; P for trend < .001).

Similarly, the highest intake of polyunsaturated fat was also associated with lower total stroke (HR, 0.88; 95% CI, 0.80-0.96; P for trend = .002). 

Highest intake of nondairy animal fat, however, was associated with an increased risk for total stroke (HR, 1.16; 95% CI, 1.05-1.29; P for trend < .001). They observed “similar associations” for ischemic stroke, but the only positive association for nondairy animal fat was with hemorrhagic stroke, the abstract notes.   

The risk for stroke was lower by 9% per serving per day for vegetable oil but increased by 8% and 12%, respectively, per serving of total red meat or processed red meat.

The association for vegetable oil was attenuated after adjustment for vegetable fat or polyunsaturated fat, whereas adjustment for nondairy animal fat rendered the association for total red meat and processed red meat nonsignificant. 

The study was funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Dr. Wang has no relevant financial disclosures. Dr. Mente has received research funding from the Dairy Farmers of Canada and the National Dairy Council to analyze data on dairy consumption and health outcomes in the PURE study, which is funded by the Population Health Research Institute, Hamilton Health Sciences Research Institute, and more than 70 other sources (government and pharmaceutical).

A version of this article first appeared on Medscape.com.

Higher intake of vegetable fats from foods such as olive oil and nuts is associated with a lower risk for stroke, whereas people who eat more animal fats, especially processed red meats, may have a higher stroke risk, observational findings suggest.

camij/thinkstockphotos.com

In a study of more than 117,000 health professionals who were followed for 27 years, those whose diet was in the highest quintile for intake of vegetable fat had a 12% lower risk for stroke, compared with those who consumed the least amount of vegetable fats.

Conversely, having the highest intake of animal fat from nondairy sources was associated with a 16% increased risk of stroke.

Fenglei Wang, PhD, presented these results at the American Heart Association scientific sessions.

“Our findings support the Dietary Guidelines for Americans and dietary recommendations by AHA,” Dr. Wang, a postdoctoral fellow in the department of nutrition at Harvard University’s T.H. Chan School of Public Health in Boston, told this news organization.

“The main sources of vegetable fat have a large overlap with polyunsaturated fat, such as vegetable oils, nuts, walnuts, and peanut butter,” Dr. Wang noted, adding that fish, especially fatty fish, is a main source of polyunsaturated fat and is recommended for cardiovascular health.

“We would recommend that people reduce consumption of red and processed meat, minimize fatty parts of unprocessed meat if consumed, and replace lard or tallow (beef fat) with nontropical vegetable oils, such as olive oil, corn, or soybean oils in cooking, to lower their stroke risk,” she said.

Moreover, although the results from this study of dietary fat are informative, Dr. Wang continued, “there are other dietary factors (fruits, vegetables, salt, alcohol, et cetera), and lifestyle factors (physical activity, smoking, et cetera), that are associated with stroke risk and worthy of attention as well.”

“Many processed meats are high in salt and saturated fat, and low in vegetable fat,” Alice H. Lichtenstein, DSc, an AHA spokesperson who was not involved with this research, noted in a press release.

“Research shows that replacing processed meat with other protein sources, particularly plant sources, is associated with lower death rates,” added Dr. Lichtenstein, the Stanley N. Gershoff professor of nutrition science and policy at Tufts University in Boston, and lead author of the AHA’s 2021 scientific statement, Dietary Guidance to Improve Cardiovascular Health.

“Key features of a heart-healthy diet pattern,” she summarized, “are to balance calorie intake with calorie needs to achieve and maintain a healthy weight; choose whole grains, lean and plant-based protein, and a variety of fruits and vegetables; limit salt, sugar, animal fat, processed foods, and alcohol; and apply this guidance regardless of where the food is prepared or consumed.”
 

Replace processed meat with plant proteins

The focus on stroke in this study “is important” because, traditionally, studies of diet and cardiovascular health have focused on coronary heart disease, Andrew Mente, PhD, who also was not involved in this research, said in an email to this news organization.

“Overall, the take-home message from the study is that replacing processed meat with plant sources of protein in the diet is probably beneficial,” Dr. Mente, associate professor, health research methods, evidence, and impact, Faculty of Health Sciences, McMaster University, Hamilton, Ont., said.

The finding that people who ate the most vegetable fat had a modest 12% lower risk of stroke than those who ate the least vegetable fat “points to protective effects of foods like seeds, nuts, vegetables, and olive oil, which has been shown previously,” he continued.

The highest quintile of total red meat intake was associated with an 8% higher risk for stroke, but this was driven mainly by processed red meat (which was associated with a 12% higher risk for stroke). These findings are “generally consistent with cohort studies showing that processed meat, as with most highly processed foods for that matter, are associated with an increased risk of cardiovascular events,” Dr. Mente noted.

“Surprisingly, dairy products (such as cheese, butter, or milk) in the study were not connected with the risk of stroke,” he added. This finding differs from results of meta-analyses of multiple cohort studies of dairy intake and stroke and the recent large international PURE study, which showed that dairy intake was associated with a lower risk for stroke.

“What is needed to move the field forward,” according to Dr. Mente, “is to employ new methods that use cutting-edge technology to study nutritional biomarkers and health outcomes.”

“When dealing with modest associations as usually encountered in nutrition, it is a challenge to make causal connections based on dietary questionnaires, which are fraught with measurement error,” he added. “The use of novel methods is where the field is headed.”
 

Total dietary fat, different types, and different food sources

Dr. Wang and colleagues investigated how total dietary fat, different types of fat, and fats from different foods were associated with incident stroke in 73,867 women in the 1984-2016 Nurses’ Health Study and 43,269 men who participated in the 1986-2016 Health Professionals Follow-up Study.

The participants had an average age of 50 years, 63% were women, and 97% were White. They replied to food-frequency questionnaires every 4 years.

Total red meat included beef, pork, or lamb (as a main dish or in sandwiches or mixed dishes) as well as processed red meats (such as bacon, sausage, bologna, hot dogs, and salami).

Animal fat sources included meat, beef tallow, lard, and full-fat dairy products, such as full-fat milk and cheese.

The median percentage of total daily calories from different sources of fat ranged from 10% to 20% for vegetable fat, 3% to 10% for dairy fat, and 7% to 17% for nondairy animal fat (for lowest to highest quintiles).

The median percentage of total daily calories from different types of fat ranged from 5% to 8% for polyunsaturated fat, 4% to 7% for n-6 polyunsaturated fat, 9% to 15% for monounsaturated fat, 8% to 14% for saturated fat, and 1% to 2% for trans fat.

During follow-up, there were 6,189 incident strokes, including 2,967 ischemic strokes and 814 hemorrhagic strokes.

The researchers found that intake in the highest quintile of vegetable fat was associated with a lower risk for total stroke, compared with the lowest quintile (hazard ratio, 0.88; 95% confidence interval, 0.81-0.96; P for trend < .001).

Similarly, the highest intake of polyunsaturated fat was also associated with lower total stroke (HR, 0.88; 95% CI, 0.80-0.96; P for trend = .002). 

Highest intake of nondairy animal fat, however, was associated with an increased risk for total stroke (HR, 1.16; 95% CI, 1.05-1.29; P for trend < .001). They observed “similar associations” for ischemic stroke, but the only positive association for nondairy animal fat was with hemorrhagic stroke, the abstract notes.   

The risk for stroke was lower by 9% per serving per day for vegetable oil but increased by 8% and 12%, respectively, per serving of total red meat or processed red meat.

The association for vegetable oil was attenuated after adjustment for vegetable fat or polyunsaturated fat, whereas adjustment for nondairy animal fat rendered the association for total red meat and processed red meat nonsignificant. 

The study was funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Dr. Wang has no relevant financial disclosures. Dr. Mente has received research funding from the Dairy Farmers of Canada and the National Dairy Council to analyze data on dairy consumption and health outcomes in the PURE study, which is funded by the Population Health Research Institute, Hamilton Health Sciences Research Institute, and more than 70 other sources (government and pharmaceutical).

A version of this article first appeared on Medscape.com.

Patients with acute coronary syndromes who have been taking the antiplatelet medication, ticagrelor, and who need coronary artery bypass surgery (CABG) may be able to safely have the procedure earlier than typically recommended, a new randomized trial suggests.

The RAPID CABG trial found that early surgery 2-3 days after ticagrelor cessation was noninferior in incurring severe or massive perioperative bleeding, compared with waiting 5-7 days. There was also no significant difference in TIMI CABG or Bleeding Academic Research Consortium (BARC) type 4 or 5 bleeding.

Patients in the delayed group had a numerically higher number of ischemic events requiring earlier surgery and had a longer hospital stay.

The study was presented at the American Heart Association scientific sessions.

“RAPID CABG is the first and only randomized controlled trial evaluating the safety of early surgery in patients taking ticagrelor,” said lead investigator Derek So, MD.

Dr. So, a cardiologist at the University of Ottawa Heart Institute and a professor at the University of Ottawa, explained that ticagrelor is a first-line antiplatelet agent for patients with acute coronary syndromes (ACS), but around 10% of patients presenting with ACS require CABG surgery.

A major concern among patients requiring bypass surgery is perioperative bleeding, and it has been shown that patients undergoing urgent bypass within 24 hours of the last dose of ticagrelor have increased mortality. Accordingly, guidelines suggest a waiting period for patients not requiring urgent bypass surgery, Dr. So noted.

Current North American guidelines suggest a waiting period of at least 5 days after stopping ticagrelor before bypass surgery. In contrast, the updated European and Japanese guidelines suggest a waiting period of 3 days.

Dr. So noted that all of the guidelines are based on cohort studies and pharmacodynamic studies, with no randomized evidence. Pharmacodynamic studies have shown that at 48 hours after the last dose of ticagrelor, the level of platelet inhibition drops to the same levels seen with long-term treatment with clopidogrel, a weaker antiplatelet drug, and after 120 hours (5 days) the effect has completely worn off.

Dr. So concluded that these new results from the RAPID CABG trial “may influence future iterations of North American guidelines with reduced waiting prior to bypass surgery” for patients receiving ticagrelor, and “they could also strengthen the level of evidence in European and Asian guidelines.”

Designated discussant of the RAPID CABG trial, Roxana Mehran, MD, professor of medicine at the Icahn School of Medicine at Mount Sinai, New York, said this was a “very important study,” being the only randomized trial to look at this issue to date.

Dr. Mehran noted that the results showed a similar number of major life-threatening bleeding events in the early and delayed groups and met the noninferiority endpoint, but she pointed out that the trial had a small sample size and a small number of events. “Therefore, larger trials are needed to verify these important and encouraging results.”

However, she concluded that these results should be considered in decisions about the timing of bypass surgery in patients receiving ticagrelor. “I will be changing my practice and sending patients earlier based on this data,” she said.

 RAPID CABG

RAPID CABG was a physician-initiated multicenter randomized study evaluating the safety of early surgery at 2-3 days after ticagrelor cessation, compared with a delay of 5-7 days among patients presenting with ACS who required nonemergency CABG surgery.

The study enrolled 143 patients with ACS who were receiving ticagrelor and needed CABG surgery. Patients with stenting for culprit lesions, those requiring urgent surgery (less than 24 hours after presentation), and those requiring valve surgery were excluded.   

Three patients declined surgery, and several others underwent surgery outside the assigned time window, so the results were based on the per protocol analysis of patients who actually had CABG in the assigned time window: 65 patients in the early CABG group and 58 in the delayed group.

The mean time from last ticagrelor dose to surgery was 3 days in the early group and 6 days in the delayed group.

Platelet reactivity on the VerifyNow test showed more residual antiplatelet activity in the early group, with P2Y12 reaction unit (PRU) levels of 200 (vs. 251 in the delayed group). This test measures the extent of platelet aggregation in the presence of P2Y12-inhibitor drugs, with lower PRU levels showing stronger antiplatelet effects.

The primary outcome of the study was severe or massive bleeding by Universal Definition of Perioperative Bleeding (UDPB) class 3 or 4. This is defined as a blood transfusions of more than 5 units of red blood cells or plasma within 24 hours of surgical closure, chest tube drainage of over 1,000 mL in the first 12 hours, and reoperation for bleeding.

Results showed that 4.6% of the early-surgery group had a primary outcome bleeding event, compared with 5.2% of the delayed surgery group, meeting the criteria for noninferiority (P = .0253 for noninferiority).

Individual components of the primary endpoint showed three class 3 (severe) bleeding events in both groups and no class 4 (massive) bleeding events in either group.  

In terms of other bleeding outcomes, TIMI CABG bleeding occurred in two patients (3.1%) in the early-surgery group vs. no patients in the delayed group; BARC 4 bleeding occurred in two patients (3.1%) in the early group versus none in the delayed group, and there were no BARC 5 bleeding events in either group.

In the intention-to-treat analysis, ischemic events before surgery occurred in six patients (8.7%) in the delayed group (one myocardial infarction, four cases of recurrent ischemia, and one ventricular tachycardia) versus none in the early group.

Cumulative 6-month ischemic events occurred in nine patients (13.0%) in the delayed group vs. four patients (5.6%) in the early group, the difference being driven by nonfatal MI and recurrent ischemia.  

There were no cardiovascular deaths in either group and one all-cause death in both groups.

Patients undergoing early surgery also had a shorter hospitalization, with a median length of stay of 9 days versus 12 days in the delayed group.

Larger trial needed

Commenting on the RAPID CABG study at an AHA press conference, Joanna Chikwe, MD, chair of the cardiac surgery department at Cedars-Sinai Medical Center, Los Angeles, said the results were in line with her practice.

“These results confirm what I already think is safe,” she said. “I’m comfortable going within 48 hours. But we individualize our approach, so it was helpful that the study investigators included platelet reactivity data. The interesting thing for me in this study was the number of adverse events in patients who waited longer.” 

Dr. Chikwe said her top-line message was that “Surgery looked incredibly safe; there was amazingly low mortality. And if a patient has an indication for surgery, waiting does not serve you well.”

However, she also cautioned that the trial was somewhat underpowered, with a small number of events that drove the primary outcome, leading to some uncertainty on the results.

“The RAPID trial was helpful, and although it confirms my practice, I think physicians may want to see a larger-powered trial to be convincingly compelled that they should change their practice,” Dr. Chikwe noted.  

She added that clinical trials in cardiac surgery are driven by inherent challenges. “Cardiac surgery is not very common, and it is hard to recruit patients into these trials, so you are generally tied to a small number of patients, and you therefore have to be extremely thoughtful about the study design. It is almost a given that you will need to use surrogate endpoints, and the choice of the surrogate endpoint can determine which way the trial goes.”

The RAPID CABG study was funded by the Canadian Institutes of Health Research. Dr. So reports research support, consultancy, or speaker’s fees from AggreDyne, Roche Diagnostics, Fujimori Kogyo, and AstraZeneca Canada. Dr. Mehran reports that her institution has received significant trial funding from AstraZeneca (the manufacturer of ticagrelor).  

A version of this article first appeared on Medscape.com.

Patients with acute coronary syndromes who have been taking the antiplatelet medication, ticagrelor, and who need coronary artery bypass surgery (CABG) may be able to safely have the procedure earlier than typically recommended, a new randomized trial suggests.

The RAPID CABG trial found that early surgery 2-3 days after ticagrelor cessation was noninferior in incurring severe or massive perioperative bleeding, compared with waiting 5-7 days. There was also no significant difference in TIMI CABG or Bleeding Academic Research Consortium (BARC) type 4 or 5 bleeding.

Patients in the delayed group had a numerically higher number of ischemic events requiring earlier surgery and had a longer hospital stay.

The study was presented at the American Heart Association scientific sessions.

“RAPID CABG is the first and only randomized controlled trial evaluating the safety of early surgery in patients taking ticagrelor,” said lead investigator Derek So, MD.

Dr. So, a cardiologist at the University of Ottawa Heart Institute and a professor at the University of Ottawa, explained that ticagrelor is a first-line antiplatelet agent for patients with acute coronary syndromes (ACS), but around 10% of patients presenting with ACS require CABG surgery.

A major concern among patients requiring bypass surgery is perioperative bleeding, and it has been shown that patients undergoing urgent bypass within 24 hours of the last dose of ticagrelor have increased mortality. Accordingly, guidelines suggest a waiting period for patients not requiring urgent bypass surgery, Dr. So noted.

Current North American guidelines suggest a waiting period of at least 5 days after stopping ticagrelor before bypass surgery. In contrast, the updated European and Japanese guidelines suggest a waiting period of 3 days.

Dr. So noted that all of the guidelines are based on cohort studies and pharmacodynamic studies, with no randomized evidence. Pharmacodynamic studies have shown that at 48 hours after the last dose of ticagrelor, the level of platelet inhibition drops to the same levels seen with long-term treatment with clopidogrel, a weaker antiplatelet drug, and after 120 hours (5 days) the effect has completely worn off.

Dr. So concluded that these new results from the RAPID CABG trial “may influence future iterations of North American guidelines with reduced waiting prior to bypass surgery” for patients receiving ticagrelor, and “they could also strengthen the level of evidence in European and Asian guidelines.”

Designated discussant of the RAPID CABG trial, Roxana Mehran, MD, professor of medicine at the Icahn School of Medicine at Mount Sinai, New York, said this was a “very important study,” being the only randomized trial to look at this issue to date.

Dr. Mehran noted that the results showed a similar number of major life-threatening bleeding events in the early and delayed groups and met the noninferiority endpoint, but she pointed out that the trial had a small sample size and a small number of events. “Therefore, larger trials are needed to verify these important and encouraging results.”

However, she concluded that these results should be considered in decisions about the timing of bypass surgery in patients receiving ticagrelor. “I will be changing my practice and sending patients earlier based on this data,” she said.

 RAPID CABG

RAPID CABG was a physician-initiated multicenter randomized study evaluating the safety of early surgery at 2-3 days after ticagrelor cessation, compared with a delay of 5-7 days among patients presenting with ACS who required nonemergency CABG surgery.

The study enrolled 143 patients with ACS who were receiving ticagrelor and needed CABG surgery. Patients with stenting for culprit lesions, those requiring urgent surgery (less than 24 hours after presentation), and those requiring valve surgery were excluded.   

Three patients declined surgery, and several others underwent surgery outside the assigned time window, so the results were based on the per protocol analysis of patients who actually had CABG in the assigned time window: 65 patients in the early CABG group and 58 in the delayed group.

The mean time from last ticagrelor dose to surgery was 3 days in the early group and 6 days in the delayed group.

Platelet reactivity on the VerifyNow test showed more residual antiplatelet activity in the early group, with P2Y12 reaction unit (PRU) levels of 200 (vs. 251 in the delayed group). This test measures the extent of platelet aggregation in the presence of P2Y12-inhibitor drugs, with lower PRU levels showing stronger antiplatelet effects.

The primary outcome of the study was severe or massive bleeding by Universal Definition of Perioperative Bleeding (UDPB) class 3 or 4. This is defined as a blood transfusions of more than 5 units of red blood cells or plasma within 24 hours of surgical closure, chest tube drainage of over 1,000 mL in the first 12 hours, and reoperation for bleeding.

Results showed that 4.6% of the early-surgery group had a primary outcome bleeding event, compared with 5.2% of the delayed surgery group, meeting the criteria for noninferiority (P = .0253 for noninferiority).

Individual components of the primary endpoint showed three class 3 (severe) bleeding events in both groups and no class 4 (massive) bleeding events in either group.  

In terms of other bleeding outcomes, TIMI CABG bleeding occurred in two patients (3.1%) in the early-surgery group vs. no patients in the delayed group; BARC 4 bleeding occurred in two patients (3.1%) in the early group versus none in the delayed group, and there were no BARC 5 bleeding events in either group.

In the intention-to-treat analysis, ischemic events before surgery occurred in six patients (8.7%) in the delayed group (one myocardial infarction, four cases of recurrent ischemia, and one ventricular tachycardia) versus none in the early group.

Cumulative 6-month ischemic events occurred in nine patients (13.0%) in the delayed group vs. four patients (5.6%) in the early group, the difference being driven by nonfatal MI and recurrent ischemia.  

There were no cardiovascular deaths in either group and one all-cause death in both groups.

Patients undergoing early surgery also had a shorter hospitalization, with a median length of stay of 9 days versus 12 days in the delayed group.

Larger trial needed

Commenting on the RAPID CABG study at an AHA press conference, Joanna Chikwe, MD, chair of the cardiac surgery department at Cedars-Sinai Medical Center, Los Angeles, said the results were in line with her practice.

“These results confirm what I already think is safe,” she said. “I’m comfortable going within 48 hours. But we individualize our approach, so it was helpful that the study investigators included platelet reactivity data. The interesting thing for me in this study was the number of adverse events in patients who waited longer.” 

Dr. Chikwe said her top-line message was that “Surgery looked incredibly safe; there was amazingly low mortality. And if a patient has an indication for surgery, waiting does not serve you well.”

However, she also cautioned that the trial was somewhat underpowered, with a small number of events that drove the primary outcome, leading to some uncertainty on the results.

“The RAPID trial was helpful, and although it confirms my practice, I think physicians may want to see a larger-powered trial to be convincingly compelled that they should change their practice,” Dr. Chikwe noted.  

She added that clinical trials in cardiac surgery are driven by inherent challenges. “Cardiac surgery is not very common, and it is hard to recruit patients into these trials, so you are generally tied to a small number of patients, and you therefore have to be extremely thoughtful about the study design. It is almost a given that you will need to use surrogate endpoints, and the choice of the surrogate endpoint can determine which way the trial goes.”

The RAPID CABG study was funded by the Canadian Institutes of Health Research. Dr. So reports research support, consultancy, or speaker’s fees from AggreDyne, Roche Diagnostics, Fujimori Kogyo, and AstraZeneca Canada. Dr. Mehran reports that her institution has received significant trial funding from AstraZeneca (the manufacturer of ticagrelor).  

A version of this article first appeared on Medscape.com.

Patients with acute coronary syndromes who have been taking the antiplatelet medication, ticagrelor, and who need coronary artery bypass surgery (CABG) may be able to safely have the procedure earlier than typically recommended, a new randomized trial suggests.

The RAPID CABG trial found that early surgery 2-3 days after ticagrelor cessation was noninferior in incurring severe or massive perioperative bleeding, compared with waiting 5-7 days. There was also no significant difference in TIMI CABG or Bleeding Academic Research Consortium (BARC) type 4 or 5 bleeding.

Patients in the delayed group had a numerically higher number of ischemic events requiring earlier surgery and had a longer hospital stay.

The study was presented at the American Heart Association scientific sessions.

“RAPID CABG is the first and only randomized controlled trial evaluating the safety of early surgery in patients taking ticagrelor,” said lead investigator Derek So, MD.

Dr. So, a cardiologist at the University of Ottawa Heart Institute and a professor at the University of Ottawa, explained that ticagrelor is a first-line antiplatelet agent for patients with acute coronary syndromes (ACS), but around 10% of patients presenting with ACS require CABG surgery.

A major concern among patients requiring bypass surgery is perioperative bleeding, and it has been shown that patients undergoing urgent bypass within 24 hours of the last dose of ticagrelor have increased mortality. Accordingly, guidelines suggest a waiting period for patients not requiring urgent bypass surgery, Dr. So noted.

Current North American guidelines suggest a waiting period of at least 5 days after stopping ticagrelor before bypass surgery. In contrast, the updated European and Japanese guidelines suggest a waiting period of 3 days.

Dr. So noted that all of the guidelines are based on cohort studies and pharmacodynamic studies, with no randomized evidence. Pharmacodynamic studies have shown that at 48 hours after the last dose of ticagrelor, the level of platelet inhibition drops to the same levels seen with long-term treatment with clopidogrel, a weaker antiplatelet drug, and after 120 hours (5 days) the effect has completely worn off.

Dr. So concluded that these new results from the RAPID CABG trial “may influence future iterations of North American guidelines with reduced waiting prior to bypass surgery” for patients receiving ticagrelor, and “they could also strengthen the level of evidence in European and Asian guidelines.”

Designated discussant of the RAPID CABG trial, Roxana Mehran, MD, professor of medicine at the Icahn School of Medicine at Mount Sinai, New York, said this was a “very important study,” being the only randomized trial to look at this issue to date.

Dr. Mehran noted that the results showed a similar number of major life-threatening bleeding events in the early and delayed groups and met the noninferiority endpoint, but she pointed out that the trial had a small sample size and a small number of events. “Therefore, larger trials are needed to verify these important and encouraging results.”

However, she concluded that these results should be considered in decisions about the timing of bypass surgery in patients receiving ticagrelor. “I will be changing my practice and sending patients earlier based on this data,” she said.

 RAPID CABG

RAPID CABG was a physician-initiated multicenter randomized study evaluating the safety of early surgery at 2-3 days after ticagrelor cessation, compared with a delay of 5-7 days among patients presenting with ACS who required nonemergency CABG surgery.

The study enrolled 143 patients with ACS who were receiving ticagrelor and needed CABG surgery. Patients with stenting for culprit lesions, those requiring urgent surgery (less than 24 hours after presentation), and those requiring valve surgery were excluded.   

Three patients declined surgery, and several others underwent surgery outside the assigned time window, so the results were based on the per protocol analysis of patients who actually had CABG in the assigned time window: 65 patients in the early CABG group and 58 in the delayed group.

The mean time from last ticagrelor dose to surgery was 3 days in the early group and 6 days in the delayed group.

Platelet reactivity on the VerifyNow test showed more residual antiplatelet activity in the early group, with P2Y12 reaction unit (PRU) levels of 200 (vs. 251 in the delayed group). This test measures the extent of platelet aggregation in the presence of P2Y12-inhibitor drugs, with lower PRU levels showing stronger antiplatelet effects.

The primary outcome of the study was severe or massive bleeding by Universal Definition of Perioperative Bleeding (UDPB) class 3 or 4. This is defined as a blood transfusions of more than 5 units of red blood cells or plasma within 24 hours of surgical closure, chest tube drainage of over 1,000 mL in the first 12 hours, and reoperation for bleeding.

Results showed that 4.6% of the early-surgery group had a primary outcome bleeding event, compared with 5.2% of the delayed surgery group, meeting the criteria for noninferiority (P = .0253 for noninferiority).

Individual components of the primary endpoint showed three class 3 (severe) bleeding events in both groups and no class 4 (massive) bleeding events in either group.  

In terms of other bleeding outcomes, TIMI CABG bleeding occurred in two patients (3.1%) in the early-surgery group vs. no patients in the delayed group; BARC 4 bleeding occurred in two patients (3.1%) in the early group versus none in the delayed group, and there were no BARC 5 bleeding events in either group.

In the intention-to-treat analysis, ischemic events before surgery occurred in six patients (8.7%) in the delayed group (one myocardial infarction, four cases of recurrent ischemia, and one ventricular tachycardia) versus none in the early group.

Cumulative 6-month ischemic events occurred in nine patients (13.0%) in the delayed group vs. four patients (5.6%) in the early group, the difference being driven by nonfatal MI and recurrent ischemia.  

There were no cardiovascular deaths in either group and one all-cause death in both groups.

Patients undergoing early surgery also had a shorter hospitalization, with a median length of stay of 9 days versus 12 days in the delayed group.

Larger trial needed

Commenting on the RAPID CABG study at an AHA press conference, Joanna Chikwe, MD, chair of the cardiac surgery department at Cedars-Sinai Medical Center, Los Angeles, said the results were in line with her practice.

“These results confirm what I already think is safe,” she said. “I’m comfortable going within 48 hours. But we individualize our approach, so it was helpful that the study investigators included platelet reactivity data. The interesting thing for me in this study was the number of adverse events in patients who waited longer.” 

Dr. Chikwe said her top-line message was that “Surgery looked incredibly safe; there was amazingly low mortality. And if a patient has an indication for surgery, waiting does not serve you well.”

However, she also cautioned that the trial was somewhat underpowered, with a small number of events that drove the primary outcome, leading to some uncertainty on the results.

“The RAPID trial was helpful, and although it confirms my practice, I think physicians may want to see a larger-powered trial to be convincingly compelled that they should change their practice,” Dr. Chikwe noted.  

She added that clinical trials in cardiac surgery are driven by inherent challenges. “Cardiac surgery is not very common, and it is hard to recruit patients into these trials, so you are generally tied to a small number of patients, and you therefore have to be extremely thoughtful about the study design. It is almost a given that you will need to use surrogate endpoints, and the choice of the surrogate endpoint can determine which way the trial goes.”

The RAPID CABG study was funded by the Canadian Institutes of Health Research. Dr. So reports research support, consultancy, or speaker’s fees from AggreDyne, Roche Diagnostics, Fujimori Kogyo, and AstraZeneca Canada. Dr. Mehran reports that her institution has received significant trial funding from AstraZeneca (the manufacturer of ticagrelor).  

A version of this article first appeared on Medscape.com.

In large-vessel occlusion stroke, results of a randomized trial failed to show noninferiority of direct mechanical thrombectomy using the Solitaire device to the combination of intravenous (IV) thrombolysis plus mechanical thrombectomy.

In the prospective, multicenter trial, the rate of good functional outcome was 57% for patients who underwent direct thrombectomy and 65% among patients who received IV thrombolysis before undergoing thrombectomy. This result failed to demonstrate noninferiority of direct mechanical thrombectomy compared to combination therapy, the researchers conclude.

“Good outcome was high in both treatment arms, with the point estimate in favor of the bridging cohort,” said lead investigator Urs Fischer, MD, co-chair of the stroke center at Inselspital, Bern University Hospital, Switzerland, during his presentation. “Postinterventional reperfusion was very high in both treatment arms and higher in patients with bridging thrombolysis, compared to direct mechanical thrombectomy.”

The findings were presented at the 13th World Stroke Congress (WSC) 2021.
 

Two views of thrombolysis

The value of bridging thrombolysis for patients who undergo mechanical thrombectomy is a matter of debate. One argument is that, for patients with large-vessel occlusion, IV thrombolysis may improve reperfusion before and after thrombectomy and yield better clinical outcomes. The opposing argument is that bridging thrombolysis may increase the risk for distal emboli, delay mechanical thrombectomy, and increase the rate of hemorrhage.

The researchers conducted the SWIFT DIRECT trial to investigate this question. They enrolled patients with acute ischemic stroke due to occlusion of the internal carotid artery or the M1 segment of the middle cerebral artery.

The trial was conducted at 48 sites in seven European countries and Canada. The investigators randomly assigned patients to receive IV alteplase (0.9 mg/kg) plus mechanical thrombectomy with the Solitaire device or to receive direct mechanical thrombectomy with the same device. Treatment was open label, but the assessment of endpoints was blinded.

Investigators assigned 423 patients to treatment, and 408 were included in the full analysis set. Of this group, 201 participants received direct mechanical thrombectomy, and 207 received IV thrombolysis plus thrombectomy. There were three crossovers in each treatment arm.

The primary outcome was functional independence, defined as a Modified Rankin Scale (mRS) score of 0-2, at 90 days. Secondary outcomes included mortality at 90 days, mRS shift, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, successful reperfusion, and symptomatic and asymptomatic intracranial hemorrhage (ICH).
 

Noninferiority not demonstrated

At baseline, patient characteristics were well balanced between the treatment groups. The median age of the patients was 72 years, and about 50% of participants were women. The median NIHSS score was 17 in both arms.

Approximately 57% of patients who underwent direct thrombectomy and 65% of those who received IV thrombolysis plus thrombectomy were functionally independent at 90 days, the primary outcome.

In addition, the researchers found no difference in mRS shift, mortality at 90 days, or change in NIHSS score at 24 hours. Postinterventional reperfusion was very high in both arms and was higher in patients who received IV tissue plasminogen activator, compared with those who received direct mechanical thrombectomy, said Dr. Fischer.

The rate of successful postinterventional reperfusion, however, was higher among patients who received thrombolysis than among those who underwent direct thrombectomy. The rate of symptomatic ICH was 1.5% in the direct thrombectomy group and 4.9% in the thrombolysis-plus-thrombectomy group.
 

New endpoints needed?

The investigators used noninferiority margins of 12%. “This question about the noninferiority margins, that’s a very tricky and difficult one in randomized clinical trials,” said Dr. Fischer. The investigators defined their margin using the 2015 HERMES data because no trials had yet compared direct mechanical thrombectomy and bridging thrombolysis at the time.

The researchers are performing a pooled analysis of all the trials that compared bridging thrombolysis with direct mechanical thrombectomy. “We are therefore looking at several margins, and I think this is the way we should look at these noninferiority margins,” said Dr. Fischer. “There’s not a clear-cut level which you can define.”

Enrollment in the trial was well balanced with respect to gender, which is not always the case in stroke studies, said Kevin Sheth, MD, professor of neurology and neurosurgery at Yale School of Medicine, New Haven, Conn., who commented on the study for this news organization.

The findings indicate that the likelihood of there being a difference between groups on this question is low, said Dr. Sheth. Both groups had large-vessel occlusion, both received thrombectomy, and both achieved reperfusion. But the higher rate of successful reperfusion in the bridging cohort was not reflected in any of the clinical endpoints that the investigators examined.

Observing a difference in this context will require very large trials or different endpoints that are more responsive to the intervention, said Dr. Sheth. “This is going to be a challenge for not just this but for any neuroprotection trial in the future,” he said.

The study was supported by Medtronic. Dr. Fischer has served as a consultant for Medtronic, Stryker, and CSL Behring. Dr. Sheth has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

In large-vessel occlusion stroke, results of a randomized trial failed to show noninferiority of direct mechanical thrombectomy using the Solitaire device to the combination of intravenous (IV) thrombolysis plus mechanical thrombectomy.

In the prospective, multicenter trial, the rate of good functional outcome was 57% for patients who underwent direct thrombectomy and 65% among patients who received IV thrombolysis before undergoing thrombectomy. This result failed to demonstrate noninferiority of direct mechanical thrombectomy compared to combination therapy, the researchers conclude.

“Good outcome was high in both treatment arms, with the point estimate in favor of the bridging cohort,” said lead investigator Urs Fischer, MD, co-chair of the stroke center at Inselspital, Bern University Hospital, Switzerland, during his presentation. “Postinterventional reperfusion was very high in both treatment arms and higher in patients with bridging thrombolysis, compared to direct mechanical thrombectomy.”

The findings were presented at the 13th World Stroke Congress (WSC) 2021.
 

Two views of thrombolysis

The value of bridging thrombolysis for patients who undergo mechanical thrombectomy is a matter of debate. One argument is that, for patients with large-vessel occlusion, IV thrombolysis may improve reperfusion before and after thrombectomy and yield better clinical outcomes. The opposing argument is that bridging thrombolysis may increase the risk for distal emboli, delay mechanical thrombectomy, and increase the rate of hemorrhage.

The researchers conducted the SWIFT DIRECT trial to investigate this question. They enrolled patients with acute ischemic stroke due to occlusion of the internal carotid artery or the M1 segment of the middle cerebral artery.

The trial was conducted at 48 sites in seven European countries and Canada. The investigators randomly assigned patients to receive IV alteplase (0.9 mg/kg) plus mechanical thrombectomy with the Solitaire device or to receive direct mechanical thrombectomy with the same device. Treatment was open label, but the assessment of endpoints was blinded.

Investigators assigned 423 patients to treatment, and 408 were included in the full analysis set. Of this group, 201 participants received direct mechanical thrombectomy, and 207 received IV thrombolysis plus thrombectomy. There were three crossovers in each treatment arm.

The primary outcome was functional independence, defined as a Modified Rankin Scale (mRS) score of 0-2, at 90 days. Secondary outcomes included mortality at 90 days, mRS shift, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, successful reperfusion, and symptomatic and asymptomatic intracranial hemorrhage (ICH).
 

Noninferiority not demonstrated

At baseline, patient characteristics were well balanced between the treatment groups. The median age of the patients was 72 years, and about 50% of participants were women. The median NIHSS score was 17 in both arms.

Approximately 57% of patients who underwent direct thrombectomy and 65% of those who received IV thrombolysis plus thrombectomy were functionally independent at 90 days, the primary outcome.

In addition, the researchers found no difference in mRS shift, mortality at 90 days, or change in NIHSS score at 24 hours. Postinterventional reperfusion was very high in both arms and was higher in patients who received IV tissue plasminogen activator, compared with those who received direct mechanical thrombectomy, said Dr. Fischer.

The rate of successful postinterventional reperfusion, however, was higher among patients who received thrombolysis than among those who underwent direct thrombectomy. The rate of symptomatic ICH was 1.5% in the direct thrombectomy group and 4.9% in the thrombolysis-plus-thrombectomy group.
 

New endpoints needed?

The investigators used noninferiority margins of 12%. “This question about the noninferiority margins, that’s a very tricky and difficult one in randomized clinical trials,” said Dr. Fischer. The investigators defined their margin using the 2015 HERMES data because no trials had yet compared direct mechanical thrombectomy and bridging thrombolysis at the time.

The researchers are performing a pooled analysis of all the trials that compared bridging thrombolysis with direct mechanical thrombectomy. “We are therefore looking at several margins, and I think this is the way we should look at these noninferiority margins,” said Dr. Fischer. “There’s not a clear-cut level which you can define.”

Enrollment in the trial was well balanced with respect to gender, which is not always the case in stroke studies, said Kevin Sheth, MD, professor of neurology and neurosurgery at Yale School of Medicine, New Haven, Conn., who commented on the study for this news organization.

The findings indicate that the likelihood of there being a difference between groups on this question is low, said Dr. Sheth. Both groups had large-vessel occlusion, both received thrombectomy, and both achieved reperfusion. But the higher rate of successful reperfusion in the bridging cohort was not reflected in any of the clinical endpoints that the investigators examined.

Observing a difference in this context will require very large trials or different endpoints that are more responsive to the intervention, said Dr. Sheth. “This is going to be a challenge for not just this but for any neuroprotection trial in the future,” he said.

The study was supported by Medtronic. Dr. Fischer has served as a consultant for Medtronic, Stryker, and CSL Behring. Dr. Sheth has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

In large-vessel occlusion stroke, results of a randomized trial failed to show noninferiority of direct mechanical thrombectomy using the Solitaire device to the combination of intravenous (IV) thrombolysis plus mechanical thrombectomy.

In the prospective, multicenter trial, the rate of good functional outcome was 57% for patients who underwent direct thrombectomy and 65% among patients who received IV thrombolysis before undergoing thrombectomy. This result failed to demonstrate noninferiority of direct mechanical thrombectomy compared to combination therapy, the researchers conclude.

“Good outcome was high in both treatment arms, with the point estimate in favor of the bridging cohort,” said lead investigator Urs Fischer, MD, co-chair of the stroke center at Inselspital, Bern University Hospital, Switzerland, during his presentation. “Postinterventional reperfusion was very high in both treatment arms and higher in patients with bridging thrombolysis, compared to direct mechanical thrombectomy.”

The findings were presented at the 13th World Stroke Congress (WSC) 2021.
 

Two views of thrombolysis

The value of bridging thrombolysis for patients who undergo mechanical thrombectomy is a matter of debate. One argument is that, for patients with large-vessel occlusion, IV thrombolysis may improve reperfusion before and after thrombectomy and yield better clinical outcomes. The opposing argument is that bridging thrombolysis may increase the risk for distal emboli, delay mechanical thrombectomy, and increase the rate of hemorrhage.

The researchers conducted the SWIFT DIRECT trial to investigate this question. They enrolled patients with acute ischemic stroke due to occlusion of the internal carotid artery or the M1 segment of the middle cerebral artery.

The trial was conducted at 48 sites in seven European countries and Canada. The investigators randomly assigned patients to receive IV alteplase (0.9 mg/kg) plus mechanical thrombectomy with the Solitaire device or to receive direct mechanical thrombectomy with the same device. Treatment was open label, but the assessment of endpoints was blinded.

Investigators assigned 423 patients to treatment, and 408 were included in the full analysis set. Of this group, 201 participants received direct mechanical thrombectomy, and 207 received IV thrombolysis plus thrombectomy. There were three crossovers in each treatment arm.

The primary outcome was functional independence, defined as a Modified Rankin Scale (mRS) score of 0-2, at 90 days. Secondary outcomes included mortality at 90 days, mRS shift, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, successful reperfusion, and symptomatic and asymptomatic intracranial hemorrhage (ICH).
 

Noninferiority not demonstrated

At baseline, patient characteristics were well balanced between the treatment groups. The median age of the patients was 72 years, and about 50% of participants were women. The median NIHSS score was 17 in both arms.

Approximately 57% of patients who underwent direct thrombectomy and 65% of those who received IV thrombolysis plus thrombectomy were functionally independent at 90 days, the primary outcome.

In addition, the researchers found no difference in mRS shift, mortality at 90 days, or change in NIHSS score at 24 hours. Postinterventional reperfusion was very high in both arms and was higher in patients who received IV tissue plasminogen activator, compared with those who received direct mechanical thrombectomy, said Dr. Fischer.

The rate of successful postinterventional reperfusion, however, was higher among patients who received thrombolysis than among those who underwent direct thrombectomy. The rate of symptomatic ICH was 1.5% in the direct thrombectomy group and 4.9% in the thrombolysis-plus-thrombectomy group.
 

New endpoints needed?

The investigators used noninferiority margins of 12%. “This question about the noninferiority margins, that’s a very tricky and difficult one in randomized clinical trials,” said Dr. Fischer. The investigators defined their margin using the 2015 HERMES data because no trials had yet compared direct mechanical thrombectomy and bridging thrombolysis at the time.

The researchers are performing a pooled analysis of all the trials that compared bridging thrombolysis with direct mechanical thrombectomy. “We are therefore looking at several margins, and I think this is the way we should look at these noninferiority margins,” said Dr. Fischer. “There’s not a clear-cut level which you can define.”

Enrollment in the trial was well balanced with respect to gender, which is not always the case in stroke studies, said Kevin Sheth, MD, professor of neurology and neurosurgery at Yale School of Medicine, New Haven, Conn., who commented on the study for this news organization.

The findings indicate that the likelihood of there being a difference between groups on this question is low, said Dr. Sheth. Both groups had large-vessel occlusion, both received thrombectomy, and both achieved reperfusion. But the higher rate of successful reperfusion in the bridging cohort was not reflected in any of the clinical endpoints that the investigators examined.

Observing a difference in this context will require very large trials or different endpoints that are more responsive to the intervention, said Dr. Sheth. “This is going to be a challenge for not just this but for any neuroprotection trial in the future,” he said.

The study was supported by Medtronic. Dr. Fischer has served as a consultant for Medtronic, Stryker, and CSL Behring. Dr. Sheth has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

On the basis of outcomes, there was no clear winner from a trial that directly compared two modern devices used in patients undergoing percutaneous left atrial appendage (LAA) closure.

But the devices were not interchangeable for rates of complications or leaks, according to results of the open-label SWISS APERO trial, which compared the Amplatzer Amulet to the Watchman FLX device at eight participating centers in Europe.

At 45 days, the overall rates of leaks and the clinical outcomes in the two randomized groups were not significantly different, but there were differences in secondary endpoints, such as rates of peridevice leak (PDL), which were lower in the Amulet device group, and procedural complications, which were higher, Roberto Galea, MD, reported at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando.

LAA closure devices were developed as an alternative to oral anticoagulation in patients with nonvalvular atrial fibrillation. Although a similar comparison of LAA closure devices, called Amulet IDE, was recently published, that trial compared Amulet to Watchman 2.5, an earlier generation device.

Started later, SWISS APERO was also a planned comparison of Amulet and the Watchman 2.5, but the comparison switched to the Watchman FLX, when it was released in March of 2019.
 

First randomized comparison with Watchman FLX

“This is the first multicenter randomized controlled trial to include the Watchman FLX,” said Dr. Galea, a clinical investigator in the department of cardiology, Bern (Switzerland) University Hospital. He noted that Watchman FLX included some adjustments in design with the potential to reduce leak rates.

After preprocedural transesophageal echocardiography confirmed that patients had suitable anatomy to receive either device, the 221 patients who qualified for SWISS APERO were randomized. The primary endpoint was a composite of a justified crossover to a device other than the one to which they were assigned or residual patency detected by coronary computed tomography angiography (CCTA) at 45 days.

The primary endpoint was reached by 67.6% of patients randomized to the Amulet device and 70% of those randomized to Watchman Flex, a statistically nonsignificant difference (P = .71).

Because only one patient in the Amulet group and none in the Watchman group had a justified crossover to a nonrandomized device, most of the differences in the 45-day CCTA involved patency, defined as LAA density of at least 100 Hounsfield units. While the proportion of patients with leaks was similar, the types of leaks, which were stratified by underlying leak mechanism into PDL, mixed leaks (including incomplete side sealing), intradevice leaks, and leaks of unclear origin, were different.
 

Peridevice leaks twofold greater with Watchman

Those randomized to the Watchman device were more than twice as likely to have PDL (27.5% vs. 13.7%; P = .02), although no visible leak exceeded 5 mm in size. They were also more likely to have mixed leaks (14% vs. 3.8%; P = .01) and patency with no visible leak (21.0% vs. 9.5%; P = .02). There were also more device-related thrombi in the Watchman group even though the difference did not reach statistical significance (9.9% vs. 3.7%; P = .08).

Intradevice leaks (44.8% vs. 23.0%; P = .001) were the only type of patency significantly more common among patients randomized to Amulet, but the difference was relatively large. In addition, procedural complications of any type (32.4% vs. 19.1%; P = .023) were higher in the Amulet group. Most of these involved non–clinically relevant pericardial effusions, Dr. Galea said at the meeting, sponsored by the Cardiovascular Research Foundation.

The proportion of patients with adverse outcomes by 45 days was similar, but the types of complications differed. Of the six deaths, two occurred in the Amulet group as a result of periprocedural complications (one stemming from an air embolism and the other from a series of events following pericardial effusion). Three of the four deaths in the Watchman group were due to fatal bleeding. The fourth was a sudden death that occurred 30 days after the procedure.
 

Amulet IDE trial generates similar data

The much larger Amulet IDE trial, which compared Amulet to the Watchman 2.5 device, produced generally similar results. Again, the proportion of patients reaching the composite primary endpoints was similar.

The primary safety endpoint, which included death and major bleeding within 12 months of randomization, occurred in 14.5% and 14.7% of the Amulet and Watchman patients, respectively (P < .001 for noninferiority). The primary efficacy endpoint, which included stroke or systemic embolism within 18 months of randomization, occurred in 2.8% of patients in both groups.

As in SWISS APERO, the 1,878-patient Amulet IDE trial showed that the devices are similarly effective and safe but not necessarily interchangeable. Ultimately, the rate of LAA occlusion was higher for Amulet than the older generation Watchman (98.9% vs. 96.8%; P = .003) but procedural complication occurred more frequently among those randomized to the Amulet device (4.5% vs. 2.5%).

“The closure mechanisms are not the same, which might explain why we see differences in some secondary outcomes even when they perform similarly on the primary outcomes,” said Dhanunjaya R. Lakkireddy, MD, executive medical director, Kansas City (Kansas) Heart Rhythm Institute.

The lead investigator of the Amulet IDE trial, Dr. Lakkireddy was referring to both the AMULET IDE and the SWISS APERO study when he said that the currently available data do not allow one device to be considered superior to the other. He did suggest that differences between devices might still be considered meaningful in specific clinical situations or to specific clinicians.

Without studies to show objective differences, Dr. Lakkireddy suggested that training and experience is probably the most important variable in achieving treatment goals. “Operator comfort is certainly important,” he said.

Dr. Galea reports no significant financial relationships. The investigator-initiated study received funding from Abbott, the manufacturer of the Amulet device. Dr. Lakkireddy has financial relationships with Abbott, AltaThera, Medtronic, Biotronik, and Boston Scientific, which makes the Watchman device.

On the basis of outcomes, there was no clear winner from a trial that directly compared two modern devices used in patients undergoing percutaneous left atrial appendage (LAA) closure.

But the devices were not interchangeable for rates of complications or leaks, according to results of the open-label SWISS APERO trial, which compared the Amplatzer Amulet to the Watchman FLX device at eight participating centers in Europe.

At 45 days, the overall rates of leaks and the clinical outcomes in the two randomized groups were not significantly different, but there were differences in secondary endpoints, such as rates of peridevice leak (PDL), which were lower in the Amulet device group, and procedural complications, which were higher, Roberto Galea, MD, reported at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando.

LAA closure devices were developed as an alternative to oral anticoagulation in patients with nonvalvular atrial fibrillation. Although a similar comparison of LAA closure devices, called Amulet IDE, was recently published, that trial compared Amulet to Watchman 2.5, an earlier generation device.

Started later, SWISS APERO was also a planned comparison of Amulet and the Watchman 2.5, but the comparison switched to the Watchman FLX, when it was released in March of 2019.
 

First randomized comparison with Watchman FLX

“This is the first multicenter randomized controlled trial to include the Watchman FLX,” said Dr. Galea, a clinical investigator in the department of cardiology, Bern (Switzerland) University Hospital. He noted that Watchman FLX included some adjustments in design with the potential to reduce leak rates.

After preprocedural transesophageal echocardiography confirmed that patients had suitable anatomy to receive either device, the 221 patients who qualified for SWISS APERO were randomized. The primary endpoint was a composite of a justified crossover to a device other than the one to which they were assigned or residual patency detected by coronary computed tomography angiography (CCTA) at 45 days.

The primary endpoint was reached by 67.6% of patients randomized to the Amulet device and 70% of those randomized to Watchman Flex, a statistically nonsignificant difference (P = .71).

Because only one patient in the Amulet group and none in the Watchman group had a justified crossover to a nonrandomized device, most of the differences in the 45-day CCTA involved patency, defined as LAA density of at least 100 Hounsfield units. While the proportion of patients with leaks was similar, the types of leaks, which were stratified by underlying leak mechanism into PDL, mixed leaks (including incomplete side sealing), intradevice leaks, and leaks of unclear origin, were different.
 

Peridevice leaks twofold greater with Watchman

Those randomized to the Watchman device were more than twice as likely to have PDL (27.5% vs. 13.7%; P = .02), although no visible leak exceeded 5 mm in size. They were also more likely to have mixed leaks (14% vs. 3.8%; P = .01) and patency with no visible leak (21.0% vs. 9.5%; P = .02). There were also more device-related thrombi in the Watchman group even though the difference did not reach statistical significance (9.9% vs. 3.7%; P = .08).

Intradevice leaks (44.8% vs. 23.0%; P = .001) were the only type of patency significantly more common among patients randomized to Amulet, but the difference was relatively large. In addition, procedural complications of any type (32.4% vs. 19.1%; P = .023) were higher in the Amulet group. Most of these involved non–clinically relevant pericardial effusions, Dr. Galea said at the meeting, sponsored by the Cardiovascular Research Foundation.

The proportion of patients with adverse outcomes by 45 days was similar, but the types of complications differed. Of the six deaths, two occurred in the Amulet group as a result of periprocedural complications (one stemming from an air embolism and the other from a series of events following pericardial effusion). Three of the four deaths in the Watchman group were due to fatal bleeding. The fourth was a sudden death that occurred 30 days after the procedure.
 

Amulet IDE trial generates similar data

The much larger Amulet IDE trial, which compared Amulet to the Watchman 2.5 device, produced generally similar results. Again, the proportion of patients reaching the composite primary endpoints was similar.

The primary safety endpoint, which included death and major bleeding within 12 months of randomization, occurred in 14.5% and 14.7% of the Amulet and Watchman patients, respectively (P < .001 for noninferiority). The primary efficacy endpoint, which included stroke or systemic embolism within 18 months of randomization, occurred in 2.8% of patients in both groups.

As in SWISS APERO, the 1,878-patient Amulet IDE trial showed that the devices are similarly effective and safe but not necessarily interchangeable. Ultimately, the rate of LAA occlusion was higher for Amulet than the older generation Watchman (98.9% vs. 96.8%; P = .003) but procedural complication occurred more frequently among those randomized to the Amulet device (4.5% vs. 2.5%).

“The closure mechanisms are not the same, which might explain why we see differences in some secondary outcomes even when they perform similarly on the primary outcomes,” said Dhanunjaya R. Lakkireddy, MD, executive medical director, Kansas City (Kansas) Heart Rhythm Institute.

The lead investigator of the Amulet IDE trial, Dr. Lakkireddy was referring to both the AMULET IDE and the SWISS APERO study when he said that the currently available data do not allow one device to be considered superior to the other. He did suggest that differences between devices might still be considered meaningful in specific clinical situations or to specific clinicians.

Without studies to show objective differences, Dr. Lakkireddy suggested that training and experience is probably the most important variable in achieving treatment goals. “Operator comfort is certainly important,” he said.

Dr. Galea reports no significant financial relationships. The investigator-initiated study received funding from Abbott, the manufacturer of the Amulet device. Dr. Lakkireddy has financial relationships with Abbott, AltaThera, Medtronic, Biotronik, and Boston Scientific, which makes the Watchman device.

On the basis of outcomes, there was no clear winner from a trial that directly compared two modern devices used in patients undergoing percutaneous left atrial appendage (LAA) closure.

But the devices were not interchangeable for rates of complications or leaks, according to results of the open-label SWISS APERO trial, which compared the Amplatzer Amulet to the Watchman FLX device at eight participating centers in Europe.

At 45 days, the overall rates of leaks and the clinical outcomes in the two randomized groups were not significantly different, but there were differences in secondary endpoints, such as rates of peridevice leak (PDL), which were lower in the Amulet device group, and procedural complications, which were higher, Roberto Galea, MD, reported at the Transcatheter Cardiovascular Therapeutics annual meeting, held virtually and live in Orlando.

LAA closure devices were developed as an alternative to oral anticoagulation in patients with nonvalvular atrial fibrillation. Although a similar comparison of LAA closure devices, called Amulet IDE, was recently published, that trial compared Amulet to Watchman 2.5, an earlier generation device.

Started later, SWISS APERO was also a planned comparison of Amulet and the Watchman 2.5, but the comparison switched to the Watchman FLX, when it was released in March of 2019.
 

First randomized comparison with Watchman FLX

“This is the first multicenter randomized controlled trial to include the Watchman FLX,” said Dr. Galea, a clinical investigator in the department of cardiology, Bern (Switzerland) University Hospital. He noted that Watchman FLX included some adjustments in design with the potential to reduce leak rates.

After preprocedural transesophageal echocardiography confirmed that patients had suitable anatomy to receive either device, the 221 patients who qualified for SWISS APERO were randomized. The primary endpoint was a composite of a justified crossover to a device other than the one to which they were assigned or residual patency detected by coronary computed tomography angiography (CCTA) at 45 days.

The primary endpoint was reached by 67.6% of patients randomized to the Amulet device and 70% of those randomized to Watchman Flex, a statistically nonsignificant difference (P = .71).

Because only one patient in the Amulet group and none in the Watchman group had a justified crossover to a nonrandomized device, most of the differences in the 45-day CCTA involved patency, defined as LAA density of at least 100 Hounsfield units. While the proportion of patients with leaks was similar, the types of leaks, which were stratified by underlying leak mechanism into PDL, mixed leaks (including incomplete side sealing), intradevice leaks, and leaks of unclear origin, were different.
 

Peridevice leaks twofold greater with Watchman

Those randomized to the Watchman device were more than twice as likely to have PDL (27.5% vs. 13.7%; P = .02), although no visible leak exceeded 5 mm in size. They were also more likely to have mixed leaks (14% vs. 3.8%; P = .01) and patency with no visible leak (21.0% vs. 9.5%; P = .02). There were also more device-related thrombi in the Watchman group even though the difference did not reach statistical significance (9.9% vs. 3.7%; P = .08).

Intradevice leaks (44.8% vs. 23.0%; P = .001) were the only type of patency significantly more common among patients randomized to Amulet, but the difference was relatively large. In addition, procedural complications of any type (32.4% vs. 19.1%; P = .023) were higher in the Amulet group. Most of these involved non–clinically relevant pericardial effusions, Dr. Galea said at the meeting, sponsored by the Cardiovascular Research Foundation.

The proportion of patients with adverse outcomes by 45 days was similar, but the types of complications differed. Of the six deaths, two occurred in the Amulet group as a result of periprocedural complications (one stemming from an air embolism and the other from a series of events following pericardial effusion). Three of the four deaths in the Watchman group were due to fatal bleeding. The fourth was a sudden death that occurred 30 days after the procedure.
 

Amulet IDE trial generates similar data

The much larger Amulet IDE trial, which compared Amulet to the Watchman 2.5 device, produced generally similar results. Again, the proportion of patients reaching the composite primary endpoints was similar.

The primary safety endpoint, which included death and major bleeding within 12 months of randomization, occurred in 14.5% and 14.7% of the Amulet and Watchman patients, respectively (P < .001 for noninferiority). The primary efficacy endpoint, which included stroke or systemic embolism within 18 months of randomization, occurred in 2.8% of patients in both groups.

As in SWISS APERO, the 1,878-patient Amulet IDE trial showed that the devices are similarly effective and safe but not necessarily interchangeable. Ultimately, the rate of LAA occlusion was higher for Amulet than the older generation Watchman (98.9% vs. 96.8%; P = .003) but procedural complication occurred more frequently among those randomized to the Amulet device (4.5% vs. 2.5%).

“The closure mechanisms are not the same, which might explain why we see differences in some secondary outcomes even when they perform similarly on the primary outcomes,” said Dhanunjaya R. Lakkireddy, MD, executive medical director, Kansas City (Kansas) Heart Rhythm Institute.

The lead investigator of the Amulet IDE trial, Dr. Lakkireddy was referring to both the AMULET IDE and the SWISS APERO study when he said that the currently available data do not allow one device to be considered superior to the other. He did suggest that differences between devices might still be considered meaningful in specific clinical situations or to specific clinicians.

Without studies to show objective differences, Dr. Lakkireddy suggested that training and experience is probably the most important variable in achieving treatment goals. “Operator comfort is certainly important,” he said.

Dr. Galea reports no significant financial relationships. The investigator-initiated study received funding from Abbott, the manufacturer of the Amulet device. Dr. Lakkireddy has financial relationships with Abbott, AltaThera, Medtronic, Biotronik, and Boston Scientific, which makes the Watchman device.

Antithrombotic therapy in clinically stable, nonhospitalized COVID-19 patients does not offer protection against adverse cardiovascular or pulmonary events, new randomized clinical trial results suggest.

Bruce Jancin/MDedge News

Antithrombotic therapy has proven useful in acutely ill inpatients with COVID-19, but in this study, treatment with aspirin or apixaban (Eliquis) did not reduce the rate of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary causes in patients ill with COVID-19 but who were not hospitalized.

“Among symptomatic, clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome,” the authors conclude. “However, the study was terminated after enrollment of 9% of participants because of a primary event rate lower than anticipated.”

The study, which was led by Jean M. Connors, MD, Brigham and Women’s Hospital, Boston, was published online October 11 in JAMA.

The ACTIV-4B Outpatient Thrombosis Prevention Trial was a randomized, adaptive, double-blind, placebo-controlled trial that sought to compare anticoagulant and antiplatelet therapy among 7,000 symptomatic but clinically stable outpatients with COVID-19.

The trial was conducted at 52 sites in the U.S. between Sept. 2020 and June 2021, with final follow-up this past August 5, and involved minimal face-to-face interactions with study participants.

Patients were randomized in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164 patients), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days.

The primary endpoint was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause.

The trial was terminated early this past June by the independent data monitoring committee because of lower than anticipated event rates. At the time, just 657 symptomatic outpatients with COVID-19 had been enrolled.

The median age of the study participants was 54 years (Interquartile Range [IQR] 46-59); 59% were women.

The median time from diagnosis to randomization was 7 days, and the median time from randomization to initiation of study medications was 3 days.

The trial’s primary efficacy and safety analyses were restricted to patients who received at least one dose of trial medication, for a final number of 558 patients.

Among these patients, the primary endpoint occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5 mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group.

The researchers found that the absolute risk reductions compared with placebo for the primary outcome were 0.0% (95% confidence interval not calculable) in the aspirin group, 0.7% (95% confidence interval, -2.1% to 4.1%) in the prophylactic-dose apixaban group, and 1.4% (95% CI, -1.5% to 5%) in the therapeutic-dose apixaban group.

No major bleeding events were reported.

The absolute risk differences compared with placebo for clinically relevant nonmajor bleeding events were 2% (95% CI, -2.7% to 6.8%) in the aspirin group, 4.5% (95% CI, -0.7% to 10.2%) in the prophylactic-dose apixaban group, and 6.9% (95% CI, 1.4% to 12.9%) in the therapeutic-dose apixaban group.

Safety and efficacy results were similar in all randomly assigned patients.

The researchers speculated that a combination of two demographic shifts over time may have led to the lower than anticipated rate of events in ACTIV-4B.

“First, the threshold for hospital admission has markedly declined since the beginning of the pandemic, such that hospitalization is no longer limited almost exclusively to those with severe pulmonary distress likely to require mechanical ventilation,” they write. “As a result, the severity of illness among individuals with COVID-19 and destined for outpatient care has declined.”

“Second, at least within the U.S., where the trial was conducted, individuals currently being infected with SARS-CoV-2 tend to be younger and have fewer comorbidities when compared with individuals with incident infection at the onset of the pandemic,” they add.

Further, COVID-19 testing was quite limited early in the pandemic, they note, “and it is possible that the anticipated event rates based on data from registries available at that time were overestimated because the denominator (that is, the number of infected individuals overall) was essentially unknown.”
 

Robust evidence

“The ACTIV-4B trial is the first randomized trial to generate robust evidence about the effects of antithrombotic therapy in outpatients with COVID-19,” Otavio Berwanger, MD, PhD, director of the Academic Research Organization, Hospital Israelita Albert Einstein, Sao Paulo-SP, Brazil, told this news organization.

“It should be noted that this was a well-designed trial with low risk of bias. On the other hand, the main limitation is the low number of events and, consequently, the limited statistical power,” said Dr. Berwanger, who wrote an accompanying editorial.

The ACTIV-4B trial has immediate implications for clinical practice, he added.

“In this sense, considering the neutral results for major cardiopulmonary outcomes, the use of aspirin or apixaban for the management of outpatients with COVID-19 should not be recommended.”

ACTIV-4B also provides useful information for the steering committees of other ongoing trials of antithrombotic therapy for patients with COVID-19 who are not hospitalized, Dr. Berwanger added.

“In this sense, probably issues like statistical power, outcome choices, recruitment feasibility, and even futility would need to be revisited. And finally, lessons learned from the implementation of an innovative, pragmatic, and decentralized trial design represent an important legacy for future trials in cardiovascular diseases and other common conditions,” he said.

The study was funded by the National Institutes of Health, and the National Heart, Lung, and Blood Institute. Dr. Connors reports financial relationships with Bristol-Myers Squibb, Pfizer, Abbott, Alnylam, Takeda, Roche, and Sanofi. Dr. Berwanger reports financial relationships with AstraZeneca, Amgen, Servier, Bristol-Myers Squibb, Bayer, Novartis, Pfizer, and Boehringer Ingelheim.

A version of this article first appeared on Medscape.com.

Antithrombotic therapy in clinically stable, nonhospitalized COVID-19 patients does not offer protection against adverse cardiovascular or pulmonary events, new randomized clinical trial results suggest.

Bruce Jancin/MDedge News

Antithrombotic therapy has proven useful in acutely ill inpatients with COVID-19, but in this study, treatment with aspirin or apixaban (Eliquis) did not reduce the rate of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary causes in patients ill with COVID-19 but who were not hospitalized.

“Among symptomatic, clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome,” the authors conclude. “However, the study was terminated after enrollment of 9% of participants because of a primary event rate lower than anticipated.”

The study, which was led by Jean M. Connors, MD, Brigham and Women’s Hospital, Boston, was published online October 11 in JAMA.

The ACTIV-4B Outpatient Thrombosis Prevention Trial was a randomized, adaptive, double-blind, placebo-controlled trial that sought to compare anticoagulant and antiplatelet therapy among 7,000 symptomatic but clinically stable outpatients with COVID-19.

The trial was conducted at 52 sites in the U.S. between Sept. 2020 and June 2021, with final follow-up this past August 5, and involved minimal face-to-face interactions with study participants.

Patients were randomized in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164 patients), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days.

The primary endpoint was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause.

The trial was terminated early this past June by the independent data monitoring committee because of lower than anticipated event rates. At the time, just 657 symptomatic outpatients with COVID-19 had been enrolled.

The median age of the study participants was 54 years (Interquartile Range [IQR] 46-59); 59% were women.

The median time from diagnosis to randomization was 7 days, and the median time from randomization to initiation of study medications was 3 days.

The trial’s primary efficacy and safety analyses were restricted to patients who received at least one dose of trial medication, for a final number of 558 patients.

Among these patients, the primary endpoint occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5 mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group.

The researchers found that the absolute risk reductions compared with placebo for the primary outcome were 0.0% (95% confidence interval not calculable) in the aspirin group, 0.7% (95% confidence interval, -2.1% to 4.1%) in the prophylactic-dose apixaban group, and 1.4% (95% CI, -1.5% to 5%) in the therapeutic-dose apixaban group.

No major bleeding events were reported.

The absolute risk differences compared with placebo for clinically relevant nonmajor bleeding events were 2% (95% CI, -2.7% to 6.8%) in the aspirin group, 4.5% (95% CI, -0.7% to 10.2%) in the prophylactic-dose apixaban group, and 6.9% (95% CI, 1.4% to 12.9%) in the therapeutic-dose apixaban group.

Safety and efficacy results were similar in all randomly assigned patients.

The researchers speculated that a combination of two demographic shifts over time may have led to the lower than anticipated rate of events in ACTIV-4B.

“First, the threshold for hospital admission has markedly declined since the beginning of the pandemic, such that hospitalization is no longer limited almost exclusively to those with severe pulmonary distress likely to require mechanical ventilation,” they write. “As a result, the severity of illness among individuals with COVID-19 and destined for outpatient care has declined.”

“Second, at least within the U.S., where the trial was conducted, individuals currently being infected with SARS-CoV-2 tend to be younger and have fewer comorbidities when compared with individuals with incident infection at the onset of the pandemic,” they add.

Further, COVID-19 testing was quite limited early in the pandemic, they note, “and it is possible that the anticipated event rates based on data from registries available at that time were overestimated because the denominator (that is, the number of infected individuals overall) was essentially unknown.”
 

Robust evidence

“The ACTIV-4B trial is the first randomized trial to generate robust evidence about the effects of antithrombotic therapy in outpatients with COVID-19,” Otavio Berwanger, MD, PhD, director of the Academic Research Organization, Hospital Israelita Albert Einstein, Sao Paulo-SP, Brazil, told this news organization.

“It should be noted that this was a well-designed trial with low risk of bias. On the other hand, the main limitation is the low number of events and, consequently, the limited statistical power,” said Dr. Berwanger, who wrote an accompanying editorial.

The ACTIV-4B trial has immediate implications for clinical practice, he added.

“In this sense, considering the neutral results for major cardiopulmonary outcomes, the use of aspirin or apixaban for the management of outpatients with COVID-19 should not be recommended.”

ACTIV-4B also provides useful information for the steering committees of other ongoing trials of antithrombotic therapy for patients with COVID-19 who are not hospitalized, Dr. Berwanger added.

“In this sense, probably issues like statistical power, outcome choices, recruitment feasibility, and even futility would need to be revisited. And finally, lessons learned from the implementation of an innovative, pragmatic, and decentralized trial design represent an important legacy for future trials in cardiovascular diseases and other common conditions,” he said.

The study was funded by the National Institutes of Health, and the National Heart, Lung, and Blood Institute. Dr. Connors reports financial relationships with Bristol-Myers Squibb, Pfizer, Abbott, Alnylam, Takeda, Roche, and Sanofi. Dr. Berwanger reports financial relationships with AstraZeneca, Amgen, Servier, Bristol-Myers Squibb, Bayer, Novartis, Pfizer, and Boehringer Ingelheim.

A version of this article first appeared on Medscape.com.

Antithrombotic therapy in clinically stable, nonhospitalized COVID-19 patients does not offer protection against adverse cardiovascular or pulmonary events, new randomized clinical trial results suggest.

Bruce Jancin/MDedge News

Antithrombotic therapy has proven useful in acutely ill inpatients with COVID-19, but in this study, treatment with aspirin or apixaban (Eliquis) did not reduce the rate of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary causes in patients ill with COVID-19 but who were not hospitalized.

“Among symptomatic, clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome,” the authors conclude. “However, the study was terminated after enrollment of 9% of participants because of a primary event rate lower than anticipated.”

The study, which was led by Jean M. Connors, MD, Brigham and Women’s Hospital, Boston, was published online October 11 in JAMA.

The ACTIV-4B Outpatient Thrombosis Prevention Trial was a randomized, adaptive, double-blind, placebo-controlled trial that sought to compare anticoagulant and antiplatelet therapy among 7,000 symptomatic but clinically stable outpatients with COVID-19.

The trial was conducted at 52 sites in the U.S. between Sept. 2020 and June 2021, with final follow-up this past August 5, and involved minimal face-to-face interactions with study participants.

Patients were randomized in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164 patients), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days.

The primary endpoint was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause.

The trial was terminated early this past June by the independent data monitoring committee because of lower than anticipated event rates. At the time, just 657 symptomatic outpatients with COVID-19 had been enrolled.

The median age of the study participants was 54 years (Interquartile Range [IQR] 46-59); 59% were women.

The median time from diagnosis to randomization was 7 days, and the median time from randomization to initiation of study medications was 3 days.

The trial’s primary efficacy and safety analyses were restricted to patients who received at least one dose of trial medication, for a final number of 558 patients.

Among these patients, the primary endpoint occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5 mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group.

The researchers found that the absolute risk reductions compared with placebo for the primary outcome were 0.0% (95% confidence interval not calculable) in the aspirin group, 0.7% (95% confidence interval, -2.1% to 4.1%) in the prophylactic-dose apixaban group, and 1.4% (95% CI, -1.5% to 5%) in the therapeutic-dose apixaban group.

No major bleeding events were reported.

The absolute risk differences compared with placebo for clinically relevant nonmajor bleeding events were 2% (95% CI, -2.7% to 6.8%) in the aspirin group, 4.5% (95% CI, -0.7% to 10.2%) in the prophylactic-dose apixaban group, and 6.9% (95% CI, 1.4% to 12.9%) in the therapeutic-dose apixaban group.

Safety and efficacy results were similar in all randomly assigned patients.

The researchers speculated that a combination of two demographic shifts over time may have led to the lower than anticipated rate of events in ACTIV-4B.

“First, the threshold for hospital admission has markedly declined since the beginning of the pandemic, such that hospitalization is no longer limited almost exclusively to those with severe pulmonary distress likely to require mechanical ventilation,” they write. “As a result, the severity of illness among individuals with COVID-19 and destined for outpatient care has declined.”

“Second, at least within the U.S., where the trial was conducted, individuals currently being infected with SARS-CoV-2 tend to be younger and have fewer comorbidities when compared with individuals with incident infection at the onset of the pandemic,” they add.

Further, COVID-19 testing was quite limited early in the pandemic, they note, “and it is possible that the anticipated event rates based on data from registries available at that time were overestimated because the denominator (that is, the number of infected individuals overall) was essentially unknown.”
 

Robust evidence

“The ACTIV-4B trial is the first randomized trial to generate robust evidence about the effects of antithrombotic therapy in outpatients with COVID-19,” Otavio Berwanger, MD, PhD, director of the Academic Research Organization, Hospital Israelita Albert Einstein, Sao Paulo-SP, Brazil, told this news organization.

“It should be noted that this was a well-designed trial with low risk of bias. On the other hand, the main limitation is the low number of events and, consequently, the limited statistical power,” said Dr. Berwanger, who wrote an accompanying editorial.

The ACTIV-4B trial has immediate implications for clinical practice, he added.

“In this sense, considering the neutral results for major cardiopulmonary outcomes, the use of aspirin or apixaban for the management of outpatients with COVID-19 should not be recommended.”

ACTIV-4B also provides useful information for the steering committees of other ongoing trials of antithrombotic therapy for patients with COVID-19 who are not hospitalized, Dr. Berwanger added.

“In this sense, probably issues like statistical power, outcome choices, recruitment feasibility, and even futility would need to be revisited. And finally, lessons learned from the implementation of an innovative, pragmatic, and decentralized trial design represent an important legacy for future trials in cardiovascular diseases and other common conditions,” he said.

The study was funded by the National Institutes of Health, and the National Heart, Lung, and Blood Institute. Dr. Connors reports financial relationships with Bristol-Myers Squibb, Pfizer, Abbott, Alnylam, Takeda, Roche, and Sanofi. Dr. Berwanger reports financial relationships with AstraZeneca, Amgen, Servier, Bristol-Myers Squibb, Bayer, Novartis, Pfizer, and Boehringer Ingelheim.

A version of this article first appeared on Medscape.com.

Calculating the estimated glucose disposal rate (eGDR) as a proxy for the level of insulin resistance may be useful way to determine if someone with type 2 diabetes (T2D) is at risk for having a first stroke, Swedish researchers have found.

purestock/Thinkstock

In a large population-based study, the lower the eGDR score went, the higher the risk for having a first stroke became.

The eGDR score was also predictive of the chance of dying from any or a cardiovascular cause, Alexander Zabala, MD, reported at the annual meeting of the European Association for the Study of Diabetes (Abstract OP 01-4).

The link between insulin resistance and an increased risk for stroke has been known for some time, and not just in people with T2D. However, the current way of determining insulin resistance is not suitable for widespread practice.

“The goal standard technique for measuring insulin resistance is the euglycemic clamp method,” said Dr. Zabala, an internal medical resident at Södersjukhuset hospital and researcher at the Karolinska Institutet in Stockholm.

“For that reason, [the eGDR], a method based on readily available clinical factors – waist circumference, hypertension, and glycosylated hemoglobin was developed,” he explained. Body mass index can also be used in place of waist circumference, he qualified.

The eGDR has already been proven to be very precise in people with type 1 diabetes, said Dr. Zabala, and could be an “excellent tool to measure insulin resistance in a large patient population.”
 

Investigating the link between eGDR and first stroke risk

The aim of the study he presented was to see if changes in the eGDR were associated with changes in the risk of someone with T2D experiencing a first stroke, or dying from a cardiovascular or other cause.

An observational cohort was formed by first considering data on all adult patients with T2D who were logged in the Swedish National Diabetes Registry (NDR) during 2004-2016. Then anyone with a history of stroke, or with any missing data on the clinical variables needed to calculate the eGDR, were excluded.

This resulted in an overall population of 104,697 individuals, aged a mean of 63 years, who had developed T2D at around the age of 59 years. About 44% of the study population were women. The mean eGDR for the whole population was 5.6 mg/kg per min.

The study subjects were grouped according to four eGDR levels: 24,706 were in the lowest quartile of eGDR (less than 4 mg/kg per min), signifying the highest level of insulin resistance, and 18,762 were in the upper quartile of eGDR (greater than 8 mg/kg per min), signifying the lowest level of insulin resistance. The middle two groups had an eGDR between 4 and 6 mg/kg per min (40,187), and 6 and 8 mg/kg/min (21,042).

Data from the NDR were then combined with the Swedish Cause of Death register, the Swedish In-patient Care Diagnoses registry, and the Longitudinal Database for Health Insurance and Labour Market Studies (LISA) to determine the rates of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, and cardiovascular mortality.
 

Increasing insulin resistance ups risk for stroke, death

After a median follow-up of 5.6 years, 4% (4,201) of the study population had had a stroke.

“We clearly see an increased occurrence of first-time stroke in the group with the lowest eGDR, indicating worst insulin resistance, in comparison with the group with the highest eGDR, indicating less insulin resistance,” Dr. Zabala reported.

After adjustment for potential confounding factors, including age at baseline, gender, diabetes duration, among other variables, the risk for stroke was lowest in those with a high eGDR value and highest for those with a low eGDR value.

Using individuals with the lowest eGDR (less than 4 mg/kg per min) and thus greatest risk of stroke as the reference, adjusted hazard ratios (aHR) for first-time stroke were: 0.60, 0.68, and 0.77 for those with an eGDR of greater than 8, 6-8, and 4-6 mg/kg per min, respectively.

The corresponding values for risk of ischemic stroke were 0.55, 0.68, and 0.75. Regarding hemorrhagic stroke, there was no statistically significant correlation between eGDR levels and stroke occurrence. This was due to the small number of cases recorded.

As for all-cause and cardiovascular mortality, a similar pattern was seen, with higher rates of death linked to increasing insulin resistance. Adjusted hazard ratios according to increasing insulin resistance (decreasing eGDR scores) for all-cause death were 0.68, 0.75, and 0.82 and for cardiovascular mortality were 0.65, 0.75, and 0.82.

A sensitivity analysis, using BMI instead of waist circumference to calculate the eGDR, showed a similar pattern, and “interestingly, a correlation between eGDR levels and risk of hemorrhagic stroke.” Dr. Zabala said.
 

Limitations and take-homes

Of course, this is an observational cohort study, so no conclusions on causality can be made and there are no data on the use of anti-diabetic treatments specifically. But there are strengths such as covering almost all adults with T2D in Sweden and a relatively long-follow-up time.

The findings suggest that “eGDR, which may reflect insulin resistance may be a useful risk marker for stroke and death in people with type 2 diabetes,” said Dr. Zabala.

“You had a very large cohort, and that certainly makes your results very valid,” observed Peter Novodvorsky, MUDr. (Hons), PhD, MRCP, a consultant diabetologist in Trenčín, Slovakia.

Dr. Novodvorsky, who chaired the session, picked up on the lack of information about how many people were taking newer diabetes drugs, such as the glucagon-like peptide 1 receptor antagonists and sodium glucose-lowering transport 2 inhibitors.

“As we all know, these might have protective effects which are not necessarily related to the glucose lowering or insulin resistance-lowering” effects, so could have influenced the results. In terms of how practical the eGDR is for clinical practice, Dr. Zabala observed in a press release: “eGDR could be used to help T2D patients better understand and manage their risk of stroke and death. 

“It could also be of importance in research. In this era of personalized medicine, better stratification of type 2 diabetes patients will help optimize clinical trials and further vital research into treatment, diagnosis, care and prevention.”

The research was a collaboration between the Karolinska Institutet, Gothenburg University and the Swedish National Diabetes Registry. Dr. Zabala and coauthors reported having no conflicts of interest.

Calculating the estimated glucose disposal rate (eGDR) as a proxy for the level of insulin resistance may be useful way to determine if someone with type 2 diabetes (T2D) is at risk for having a first stroke, Swedish researchers have found.

purestock/Thinkstock

In a large population-based study, the lower the eGDR score went, the higher the risk for having a first stroke became.

The eGDR score was also predictive of the chance of dying from any or a cardiovascular cause, Alexander Zabala, MD, reported at the annual meeting of the European Association for the Study of Diabetes (Abstract OP 01-4).

The link between insulin resistance and an increased risk for stroke has been known for some time, and not just in people with T2D. However, the current way of determining insulin resistance is not suitable for widespread practice.

“The goal standard technique for measuring insulin resistance is the euglycemic clamp method,” said Dr. Zabala, an internal medical resident at Södersjukhuset hospital and researcher at the Karolinska Institutet in Stockholm.

“For that reason, [the eGDR], a method based on readily available clinical factors – waist circumference, hypertension, and glycosylated hemoglobin was developed,” he explained. Body mass index can also be used in place of waist circumference, he qualified.

The eGDR has already been proven to be very precise in people with type 1 diabetes, said Dr. Zabala, and could be an “excellent tool to measure insulin resistance in a large patient population.”
 

Investigating the link between eGDR and first stroke risk

The aim of the study he presented was to see if changes in the eGDR were associated with changes in the risk of someone with T2D experiencing a first stroke, or dying from a cardiovascular or other cause.

An observational cohort was formed by first considering data on all adult patients with T2D who were logged in the Swedish National Diabetes Registry (NDR) during 2004-2016. Then anyone with a history of stroke, or with any missing data on the clinical variables needed to calculate the eGDR, were excluded.

This resulted in an overall population of 104,697 individuals, aged a mean of 63 years, who had developed T2D at around the age of 59 years. About 44% of the study population were women. The mean eGDR for the whole population was 5.6 mg/kg per min.

The study subjects were grouped according to four eGDR levels: 24,706 were in the lowest quartile of eGDR (less than 4 mg/kg per min), signifying the highest level of insulin resistance, and 18,762 were in the upper quartile of eGDR (greater than 8 mg/kg per min), signifying the lowest level of insulin resistance. The middle two groups had an eGDR between 4 and 6 mg/kg per min (40,187), and 6 and 8 mg/kg/min (21,042).

Data from the NDR were then combined with the Swedish Cause of Death register, the Swedish In-patient Care Diagnoses registry, and the Longitudinal Database for Health Insurance and Labour Market Studies (LISA) to determine the rates of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, and cardiovascular mortality.
 

Increasing insulin resistance ups risk for stroke, death

After a median follow-up of 5.6 years, 4% (4,201) of the study population had had a stroke.

“We clearly see an increased occurrence of first-time stroke in the group with the lowest eGDR, indicating worst insulin resistance, in comparison with the group with the highest eGDR, indicating less insulin resistance,” Dr. Zabala reported.

After adjustment for potential confounding factors, including age at baseline, gender, diabetes duration, among other variables, the risk for stroke was lowest in those with a high eGDR value and highest for those with a low eGDR value.

Using individuals with the lowest eGDR (less than 4 mg/kg per min) and thus greatest risk of stroke as the reference, adjusted hazard ratios (aHR) for first-time stroke were: 0.60, 0.68, and 0.77 for those with an eGDR of greater than 8, 6-8, and 4-6 mg/kg per min, respectively.

The corresponding values for risk of ischemic stroke were 0.55, 0.68, and 0.75. Regarding hemorrhagic stroke, there was no statistically significant correlation between eGDR levels and stroke occurrence. This was due to the small number of cases recorded.

As for all-cause and cardiovascular mortality, a similar pattern was seen, with higher rates of death linked to increasing insulin resistance. Adjusted hazard ratios according to increasing insulin resistance (decreasing eGDR scores) for all-cause death were 0.68, 0.75, and 0.82 and for cardiovascular mortality were 0.65, 0.75, and 0.82.

A sensitivity analysis, using BMI instead of waist circumference to calculate the eGDR, showed a similar pattern, and “interestingly, a correlation between eGDR levels and risk of hemorrhagic stroke.” Dr. Zabala said.
 

Limitations and take-homes

Of course, this is an observational cohort study, so no conclusions on causality can be made and there are no data on the use of anti-diabetic treatments specifically. But there are strengths such as covering almost all adults with T2D in Sweden and a relatively long-follow-up time.

The findings suggest that “eGDR, which may reflect insulin resistance may be a useful risk marker for stroke and death in people with type 2 diabetes,” said Dr. Zabala.

“You had a very large cohort, and that certainly makes your results very valid,” observed Peter Novodvorsky, MUDr. (Hons), PhD, MRCP, a consultant diabetologist in Trenčín, Slovakia.

Dr. Novodvorsky, who chaired the session, picked up on the lack of information about how many people were taking newer diabetes drugs, such as the glucagon-like peptide 1 receptor antagonists and sodium glucose-lowering transport 2 inhibitors.

“As we all know, these might have protective effects which are not necessarily related to the glucose lowering or insulin resistance-lowering” effects, so could have influenced the results. In terms of how practical the eGDR is for clinical practice, Dr. Zabala observed in a press release: “eGDR could be used to help T2D patients better understand and manage their risk of stroke and death. 

“It could also be of importance in research. In this era of personalized medicine, better stratification of type 2 diabetes patients will help optimize clinical trials and further vital research into treatment, diagnosis, care and prevention.”

The research was a collaboration between the Karolinska Institutet, Gothenburg University and the Swedish National Diabetes Registry. Dr. Zabala and coauthors reported having no conflicts of interest.

Calculating the estimated glucose disposal rate (eGDR) as a proxy for the level of insulin resistance may be useful way to determine if someone with type 2 diabetes (T2D) is at risk for having a first stroke, Swedish researchers have found.

purestock/Thinkstock

In a large population-based study, the lower the eGDR score went, the higher the risk for having a first stroke became.

The eGDR score was also predictive of the chance of dying from any or a cardiovascular cause, Alexander Zabala, MD, reported at the annual meeting of the European Association for the Study of Diabetes (Abstract OP 01-4).

The link between insulin resistance and an increased risk for stroke has been known for some time, and not just in people with T2D. However, the current way of determining insulin resistance is not suitable for widespread practice.

“The goal standard technique for measuring insulin resistance is the euglycemic clamp method,” said Dr. Zabala, an internal medical resident at Södersjukhuset hospital and researcher at the Karolinska Institutet in Stockholm.

“For that reason, [the eGDR], a method based on readily available clinical factors – waist circumference, hypertension, and glycosylated hemoglobin was developed,” he explained. Body mass index can also be used in place of waist circumference, he qualified.

The eGDR has already been proven to be very precise in people with type 1 diabetes, said Dr. Zabala, and could be an “excellent tool to measure insulin resistance in a large patient population.”
 

Investigating the link between eGDR and first stroke risk

The aim of the study he presented was to see if changes in the eGDR were associated with changes in the risk of someone with T2D experiencing a first stroke, or dying from a cardiovascular or other cause.

An observational cohort was formed by first considering data on all adult patients with T2D who were logged in the Swedish National Diabetes Registry (NDR) during 2004-2016. Then anyone with a history of stroke, or with any missing data on the clinical variables needed to calculate the eGDR, were excluded.

This resulted in an overall population of 104,697 individuals, aged a mean of 63 years, who had developed T2D at around the age of 59 years. About 44% of the study population were women. The mean eGDR for the whole population was 5.6 mg/kg per min.

The study subjects were grouped according to four eGDR levels: 24,706 were in the lowest quartile of eGDR (less than 4 mg/kg per min), signifying the highest level of insulin resistance, and 18,762 were in the upper quartile of eGDR (greater than 8 mg/kg per min), signifying the lowest level of insulin resistance. The middle two groups had an eGDR between 4 and 6 mg/kg per min (40,187), and 6 and 8 mg/kg/min (21,042).

Data from the NDR were then combined with the Swedish Cause of Death register, the Swedish In-patient Care Diagnoses registry, and the Longitudinal Database for Health Insurance and Labour Market Studies (LISA) to determine the rates of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, and cardiovascular mortality.
 

Increasing insulin resistance ups risk for stroke, death

After a median follow-up of 5.6 years, 4% (4,201) of the study population had had a stroke.

“We clearly see an increased occurrence of first-time stroke in the group with the lowest eGDR, indicating worst insulin resistance, in comparison with the group with the highest eGDR, indicating less insulin resistance,” Dr. Zabala reported.

After adjustment for potential confounding factors, including age at baseline, gender, diabetes duration, among other variables, the risk for stroke was lowest in those with a high eGDR value and highest for those with a low eGDR value.

Using individuals with the lowest eGDR (less than 4 mg/kg per min) and thus greatest risk of stroke as the reference, adjusted hazard ratios (aHR) for first-time stroke were: 0.60, 0.68, and 0.77 for those with an eGDR of greater than 8, 6-8, and 4-6 mg/kg per min, respectively.

The corresponding values for risk of ischemic stroke were 0.55, 0.68, and 0.75. Regarding hemorrhagic stroke, there was no statistically significant correlation between eGDR levels and stroke occurrence. This was due to the small number of cases recorded.

As for all-cause and cardiovascular mortality, a similar pattern was seen, with higher rates of death linked to increasing insulin resistance. Adjusted hazard ratios according to increasing insulin resistance (decreasing eGDR scores) for all-cause death were 0.68, 0.75, and 0.82 and for cardiovascular mortality were 0.65, 0.75, and 0.82.

A sensitivity analysis, using BMI instead of waist circumference to calculate the eGDR, showed a similar pattern, and “interestingly, a correlation between eGDR levels and risk of hemorrhagic stroke.” Dr. Zabala said.
 

Limitations and take-homes

Of course, this is an observational cohort study, so no conclusions on causality can be made and there are no data on the use of anti-diabetic treatments specifically. But there are strengths such as covering almost all adults with T2D in Sweden and a relatively long-follow-up time.

The findings suggest that “eGDR, which may reflect insulin resistance may be a useful risk marker for stroke and death in people with type 2 diabetes,” said Dr. Zabala.

“You had a very large cohort, and that certainly makes your results very valid,” observed Peter Novodvorsky, MUDr. (Hons), PhD, MRCP, a consultant diabetologist in Trenčín, Slovakia.

Dr. Novodvorsky, who chaired the session, picked up on the lack of information about how many people were taking newer diabetes drugs, such as the glucagon-like peptide 1 receptor antagonists and sodium glucose-lowering transport 2 inhibitors.

“As we all know, these might have protective effects which are not necessarily related to the glucose lowering or insulin resistance-lowering” effects, so could have influenced the results. In terms of how practical the eGDR is for clinical practice, Dr. Zabala observed in a press release: “eGDR could be used to help T2D patients better understand and manage their risk of stroke and death. 

“It could also be of importance in research. In this era of personalized medicine, better stratification of type 2 diabetes patients will help optimize clinical trials and further vital research into treatment, diagnosis, care and prevention.”

The research was a collaboration between the Karolinska Institutet, Gothenburg University and the Swedish National Diabetes Registry. Dr. Zabala and coauthors reported having no conflicts of interest.

New risk equations can help determine the need for a first coronary artery calcium (CAC) scan in young adults to identify those most at risk for premature atherosclerosis, researchers say.

“To our knowledge this is the first time to derive a clinical risk equation for the initial conversion from CAC 0, which can be used actually to guide the timing of CAC testing in young adults,” Omar Dzaye, MD, MPH, PhD, Johns Hopkins University School of Medicine, Baltimore, said in an interview.

CAC is an independent predictor of adverse atherosclerotic cardiovascular disease (ASCVD), but routine screening is not recommended in low-risk groups. U.S. guidelines say CAC testing may be considered (class IIa) for risk stratification in adults 40 to 75 years at intermediate risk (estimated 10-year ASCVD risk 7.5% to 20%) when the decision to start preventive therapies is unclear.

The new sex-specific risk equations were derived from 22,346 adults 30 to 50 years of age who underwent CAC testing between 1991 and 2010 for ASCVD risk prediction at four high-volume centers in the CAC Consortium. The average age was 43.5 years, 25% were women, and 12.3% were non-White.

The participants were free of clinical ASCVD or CV symptoms at the time of scanning but had underlying traditional ASCVD risk factors (dyslipidemia in 49.6%, hypertension in 20.0%, active smokers 11.0%, and diabetes in 4.0%), an intermediate 10-year ASCVD risk (2.6%), and/or a significant family history of CHD (49.3%).

As reported in the Journal of the American College of Cardiology, 92.7% of participants had a low 10-year ASCVD risk below 5%, but 34.4% had CAC scores above 0 (median, 20 Agatston units).

Assuming a 25% testing yield (number needed to scan equals four to detect one CAC score above 0), the optimal age for a first scan in young men without risk factors was 42.3 years, and for women it was 57.6 years.

Young adults with one or more risk factors, however, would convert to CAC above 0 at least 3.3 years earlier on average. Diabetes had the strongest influence on the probability of conversion, with men and women predicted to develop incident CAC a respective 5.5 years and 7.3 years earlier on average.

The findings build on previous observations by the team showing that diabetes confers a 40% reduction in the so-called “warranty period” of a CAC score of 0, Dr. Dzaye noted. The National Lipid Association 2020 statement on CAC scoring also suggests it’s reasonable to obtain a CAC scan in people with diabetes aged 30 to 39 years.

“The predicted utility of CAC for ASCVD outcomes is similar in type 1 and type 2 diabetes; however, individuals with type 1 diabetes may actually develop CAC as young as 17 years of age,” he said. “Therefore, definitely, CAC studies in this population are required.”

In contrast, hypertension, dyslipidemia, active smoking, and a family history of CHD were individually associated with the development of CAC 3.3 to 4.3 years earlier. In general, the time to premature CAC was longer for women than for men with a given risk-factor profile.

The predicted age for a first CAC was 37.5 years for men and 48.9 years for women with an intermediate risk-factor profile (for example, smoking plus hypertension) and 33.8 years and 44.7 years, respectively, for those with a high-risk profile (for example, diabetes plus dyslipidemia).

Asked whether the risk equations can be used to guide CAC scanning in clinical practice, Dr. Dzaye said, “we very much believe that this can be used because for the process we published the internal validation, and we also did an external validation that is not published at the moment in [the] MESA [trial].”

He pointed out that study participants did not have a second CAC scan for true modeling of longitudinal CAC and do not represent the general population but, rather, a general cardiology referral population enriched with ASCVD risk factors. Future studies are needed that incorporate a more diverse population, multiple CAC scans, and genetic risk factors.

“This is helpful from a descriptive, epidemiologic point of view and helps us understand the approximate prevalence of coronary calcium greater than 0 in younger men and women, but I’m not convinced that it will or should change clinical practice,” cardiologist Philip Greenland, MD, a professor of preventive medicine and professor of medicine at Northwestern University in Chicago, said in an interview.

Dr. Greenland, who coauthored a review on CAC testing earlier this month, said CAC is the strongest tool we have to improve risk prediction beyond standard risk scores but does involve radiation exposure and some added costs. CAC testing is especially useful as a tiebreaker in older intermediate-risk patients who may be on the fence about starting primary prevention medications but could fall short among “younger, low-risk patients where, as they show here, the proportion of people who have a positive test is well below half.”

“So that means you’re going to have a very large number of people who are CAC 0, which is what we would expect in relatively younger people, but I wouldn’t be happy to try to explain that to a patient: ‘We’re not seeing coronary atherosclerosis right now, but we still want to treat your risk factors.’ That’s kind of a dissonant message,” Dr. Greenland said.

An accompanying editorial suggests “the study has filled an important clinical gap, providing highly actionable data that could help guide clinical decision making for ASCVD prevention.”

Nevertheless, Tasneem Naqvi, MD, Mayo Clinic, Scottsdale, Arizona, and Tamar Polonsky, MD, University of Chicago, question the generalizability of the results and point out that CAC screening at the authors’ recommended ages “could still miss a substantial number of young women with incident MI.”

Exposure to ionizing radiation with CAC is lower than that used in screening mammography for breast cancer but, they agree, should be considered, particularly in young women.

“Alternatively, ultrasonography avoids radiation altogether and can detect plaque earlier than the development of CAC,” write Dr. Naqvi and Dr. Polonsky. Further, the 2019 European Society of Cardiology guidelines for CV risk give ultrasound assessment of carotid artery and femoral plaque a class IIa recommendation and CAC a class IIb recommendation.

Commenting for this news organization, Roger Blumenthal, MD, director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease, said the class IIb recommendation “never really made any sense because the data with coronary calcium is so much stronger than it is with carotid ultrasound.”

“Sometimes smart scientists and researchers differ, but in my strong opinion, the European Society of Cardiology in 2019 did not give it the right classification, while the group I was part of, the American Heart Association/American College of Cardiology [2019 guideline], got it right and emphasized that this is the most cost-effective and useful way to improve risk assessment.”

Dr. Blumenthal, who was not part of the study, noted that U.S. guidelines say CAC measurement is not intended as a screening test for everyone but may be used selectively as a decision aid.

“This study adds to the information about how to use that type of testing. So, I personally think it will be a highly referenced article in the next set of guidelines that the American Heart Association, American College of Cardiology, and other organizations have.”

The study was supported in part by a research grant from the National Institutes of Health National Heart, Lung, and Blood Institute. Dr. Dzaye, Dr. Blumenthal, Dr. Naqvi, and Dr. Polonsky report having no relevant financial relationships.

A version of this article appeared on Medscape.com.

New risk equations can help determine the need for a first coronary artery calcium (CAC) scan in young adults to identify those most at risk for premature atherosclerosis, researchers say.

“To our knowledge this is the first time to derive a clinical risk equation for the initial conversion from CAC 0, which can be used actually to guide the timing of CAC testing in young adults,” Omar Dzaye, MD, MPH, PhD, Johns Hopkins University School of Medicine, Baltimore, said in an interview.

CAC is an independent predictor of adverse atherosclerotic cardiovascular disease (ASCVD), but routine screening is not recommended in low-risk groups. U.S. guidelines say CAC testing may be considered (class IIa) for risk stratification in adults 40 to 75 years at intermediate risk (estimated 10-year ASCVD risk 7.5% to 20%) when the decision to start preventive therapies is unclear.

The new sex-specific risk equations were derived from 22,346 adults 30 to 50 years of age who underwent CAC testing between 1991 and 2010 for ASCVD risk prediction at four high-volume centers in the CAC Consortium. The average age was 43.5 years, 25% were women, and 12.3% were non-White.

The participants were free of clinical ASCVD or CV symptoms at the time of scanning but had underlying traditional ASCVD risk factors (dyslipidemia in 49.6%, hypertension in 20.0%, active smokers 11.0%, and diabetes in 4.0%), an intermediate 10-year ASCVD risk (2.6%), and/or a significant family history of CHD (49.3%).

As reported in the Journal of the American College of Cardiology, 92.7% of participants had a low 10-year ASCVD risk below 5%, but 34.4% had CAC scores above 0 (median, 20 Agatston units).

Assuming a 25% testing yield (number needed to scan equals four to detect one CAC score above 0), the optimal age for a first scan in young men without risk factors was 42.3 years, and for women it was 57.6 years.

Young adults with one or more risk factors, however, would convert to CAC above 0 at least 3.3 years earlier on average. Diabetes had the strongest influence on the probability of conversion, with men and women predicted to develop incident CAC a respective 5.5 years and 7.3 years earlier on average.

The findings build on previous observations by the team showing that diabetes confers a 40% reduction in the so-called “warranty period” of a CAC score of 0, Dr. Dzaye noted. The National Lipid Association 2020 statement on CAC scoring also suggests it’s reasonable to obtain a CAC scan in people with diabetes aged 30 to 39 years.

“The predicted utility of CAC for ASCVD outcomes is similar in type 1 and type 2 diabetes; however, individuals with type 1 diabetes may actually develop CAC as young as 17 years of age,” he said. “Therefore, definitely, CAC studies in this population are required.”

In contrast, hypertension, dyslipidemia, active smoking, and a family history of CHD were individually associated with the development of CAC 3.3 to 4.3 years earlier. In general, the time to premature CAC was longer for women than for men with a given risk-factor profile.

The predicted age for a first CAC was 37.5 years for men and 48.9 years for women with an intermediate risk-factor profile (for example, smoking plus hypertension) and 33.8 years and 44.7 years, respectively, for those with a high-risk profile (for example, diabetes plus dyslipidemia).

Asked whether the risk equations can be used to guide CAC scanning in clinical practice, Dr. Dzaye said, “we very much believe that this can be used because for the process we published the internal validation, and we also did an external validation that is not published at the moment in [the] MESA [trial].”

He pointed out that study participants did not have a second CAC scan for true modeling of longitudinal CAC and do not represent the general population but, rather, a general cardiology referral population enriched with ASCVD risk factors. Future studies are needed that incorporate a more diverse population, multiple CAC scans, and genetic risk factors.

“This is helpful from a descriptive, epidemiologic point of view and helps us understand the approximate prevalence of coronary calcium greater than 0 in younger men and women, but I’m not convinced that it will or should change clinical practice,” cardiologist Philip Greenland, MD, a professor of preventive medicine and professor of medicine at Northwestern University in Chicago, said in an interview.

Dr. Greenland, who coauthored a review on CAC testing earlier this month, said CAC is the strongest tool we have to improve risk prediction beyond standard risk scores but does involve radiation exposure and some added costs. CAC testing is especially useful as a tiebreaker in older intermediate-risk patients who may be on the fence about starting primary prevention medications but could fall short among “younger, low-risk patients where, as they show here, the proportion of people who have a positive test is well below half.”

“So that means you’re going to have a very large number of people who are CAC 0, which is what we would expect in relatively younger people, but I wouldn’t be happy to try to explain that to a patient: ‘We’re not seeing coronary atherosclerosis right now, but we still want to treat your risk factors.’ That’s kind of a dissonant message,” Dr. Greenland said.

An accompanying editorial suggests “the study has filled an important clinical gap, providing highly actionable data that could help guide clinical decision making for ASCVD prevention.”

Nevertheless, Tasneem Naqvi, MD, Mayo Clinic, Scottsdale, Arizona, and Tamar Polonsky, MD, University of Chicago, question the generalizability of the results and point out that CAC screening at the authors’ recommended ages “could still miss a substantial number of young women with incident MI.”

Exposure to ionizing radiation with CAC is lower than that used in screening mammography for breast cancer but, they agree, should be considered, particularly in young women.

“Alternatively, ultrasonography avoids radiation altogether and can detect plaque earlier than the development of CAC,” write Dr. Naqvi and Dr. Polonsky. Further, the 2019 European Society of Cardiology guidelines for CV risk give ultrasound assessment of carotid artery and femoral plaque a class IIa recommendation and CAC a class IIb recommendation.

Commenting for this news organization, Roger Blumenthal, MD, director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease, said the class IIb recommendation “never really made any sense because the data with coronary calcium is so much stronger than it is with carotid ultrasound.”

“Sometimes smart scientists and researchers differ, but in my strong opinion, the European Society of Cardiology in 2019 did not give it the right classification, while the group I was part of, the American Heart Association/American College of Cardiology [2019 guideline], got it right and emphasized that this is the most cost-effective and useful way to improve risk assessment.”

Dr. Blumenthal, who was not part of the study, noted that U.S. guidelines say CAC measurement is not intended as a screening test for everyone but may be used selectively as a decision aid.

“This study adds to the information about how to use that type of testing. So, I personally think it will be a highly referenced article in the next set of guidelines that the American Heart Association, American College of Cardiology, and other organizations have.”

The study was supported in part by a research grant from the National Institutes of Health National Heart, Lung, and Blood Institute. Dr. Dzaye, Dr. Blumenthal, Dr. Naqvi, and Dr. Polonsky report having no relevant financial relationships.

A version of this article appeared on Medscape.com.

New risk equations can help determine the need for a first coronary artery calcium (CAC) scan in young adults to identify those most at risk for premature atherosclerosis, researchers say.

“To our knowledge this is the first time to derive a clinical risk equation for the initial conversion from CAC 0, which can be used actually to guide the timing of CAC testing in young adults,” Omar Dzaye, MD, MPH, PhD, Johns Hopkins University School of Medicine, Baltimore, said in an interview.

CAC is an independent predictor of adverse atherosclerotic cardiovascular disease (ASCVD), but routine screening is not recommended in low-risk groups. U.S. guidelines say CAC testing may be considered (class IIa) for risk stratification in adults 40 to 75 years at intermediate risk (estimated 10-year ASCVD risk 7.5% to 20%) when the decision to start preventive therapies is unclear.

The new sex-specific risk equations were derived from 22,346 adults 30 to 50 years of age who underwent CAC testing between 1991 and 2010 for ASCVD risk prediction at four high-volume centers in the CAC Consortium. The average age was 43.5 years, 25% were women, and 12.3% were non-White.

The participants were free of clinical ASCVD or CV symptoms at the time of scanning but had underlying traditional ASCVD risk factors (dyslipidemia in 49.6%, hypertension in 20.0%, active smokers 11.0%, and diabetes in 4.0%), an intermediate 10-year ASCVD risk (2.6%), and/or a significant family history of CHD (49.3%).

As reported in the Journal of the American College of Cardiology, 92.7% of participants had a low 10-year ASCVD risk below 5%, but 34.4% had CAC scores above 0 (median, 20 Agatston units).

Assuming a 25% testing yield (number needed to scan equals four to detect one CAC score above 0), the optimal age for a first scan in young men without risk factors was 42.3 years, and for women it was 57.6 years.

Young adults with one or more risk factors, however, would convert to CAC above 0 at least 3.3 years earlier on average. Diabetes had the strongest influence on the probability of conversion, with men and women predicted to develop incident CAC a respective 5.5 years and 7.3 years earlier on average.

The findings build on previous observations by the team showing that diabetes confers a 40% reduction in the so-called “warranty period” of a CAC score of 0, Dr. Dzaye noted. The National Lipid Association 2020 statement on CAC scoring also suggests it’s reasonable to obtain a CAC scan in people with diabetes aged 30 to 39 years.

“The predicted utility of CAC for ASCVD outcomes is similar in type 1 and type 2 diabetes; however, individuals with type 1 diabetes may actually develop CAC as young as 17 years of age,” he said. “Therefore, definitely, CAC studies in this population are required.”

In contrast, hypertension, dyslipidemia, active smoking, and a family history of CHD were individually associated with the development of CAC 3.3 to 4.3 years earlier. In general, the time to premature CAC was longer for women than for men with a given risk-factor profile.

The predicted age for a first CAC was 37.5 years for men and 48.9 years for women with an intermediate risk-factor profile (for example, smoking plus hypertension) and 33.8 years and 44.7 years, respectively, for those with a high-risk profile (for example, diabetes plus dyslipidemia).

Asked whether the risk equations can be used to guide CAC scanning in clinical practice, Dr. Dzaye said, “we very much believe that this can be used because for the process we published the internal validation, and we also did an external validation that is not published at the moment in [the] MESA [trial].”

He pointed out that study participants did not have a second CAC scan for true modeling of longitudinal CAC and do not represent the general population but, rather, a general cardiology referral population enriched with ASCVD risk factors. Future studies are needed that incorporate a more diverse population, multiple CAC scans, and genetic risk factors.

“This is helpful from a descriptive, epidemiologic point of view and helps us understand the approximate prevalence of coronary calcium greater than 0 in younger men and women, but I’m not convinced that it will or should change clinical practice,” cardiologist Philip Greenland, MD, a professor of preventive medicine and professor of medicine at Northwestern University in Chicago, said in an interview.

Dr. Greenland, who coauthored a review on CAC testing earlier this month, said CAC is the strongest tool we have to improve risk prediction beyond standard risk scores but does involve radiation exposure and some added costs. CAC testing is especially useful as a tiebreaker in older intermediate-risk patients who may be on the fence about starting primary prevention medications but could fall short among “younger, low-risk patients where, as they show here, the proportion of people who have a positive test is well below half.”

“So that means you’re going to have a very large number of people who are CAC 0, which is what we would expect in relatively younger people, but I wouldn’t be happy to try to explain that to a patient: ‘We’re not seeing coronary atherosclerosis right now, but we still want to treat your risk factors.’ That’s kind of a dissonant message,” Dr. Greenland said.

An accompanying editorial suggests “the study has filled an important clinical gap, providing highly actionable data that could help guide clinical decision making for ASCVD prevention.”

Nevertheless, Tasneem Naqvi, MD, Mayo Clinic, Scottsdale, Arizona, and Tamar Polonsky, MD, University of Chicago, question the generalizability of the results and point out that CAC screening at the authors’ recommended ages “could still miss a substantial number of young women with incident MI.”

Exposure to ionizing radiation with CAC is lower than that used in screening mammography for breast cancer but, they agree, should be considered, particularly in young women.

“Alternatively, ultrasonography avoids radiation altogether and can detect plaque earlier than the development of CAC,” write Dr. Naqvi and Dr. Polonsky. Further, the 2019 European Society of Cardiology guidelines for CV risk give ultrasound assessment of carotid artery and femoral plaque a class IIa recommendation and CAC a class IIb recommendation.

Commenting for this news organization, Roger Blumenthal, MD, director of the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease, said the class IIb recommendation “never really made any sense because the data with coronary calcium is so much stronger than it is with carotid ultrasound.”

“Sometimes smart scientists and researchers differ, but in my strong opinion, the European Society of Cardiology in 2019 did not give it the right classification, while the group I was part of, the American Heart Association/American College of Cardiology [2019 guideline], got it right and emphasized that this is the most cost-effective and useful way to improve risk assessment.”

Dr. Blumenthal, who was not part of the study, noted that U.S. guidelines say CAC measurement is not intended as a screening test for everyone but may be used selectively as a decision aid.

“This study adds to the information about how to use that type of testing. So, I personally think it will be a highly referenced article in the next set of guidelines that the American Heart Association, American College of Cardiology, and other organizations have.”

The study was supported in part by a research grant from the National Institutes of Health National Heart, Lung, and Blood Institute. Dr. Dzaye, Dr. Blumenthal, Dr. Naqvi, and Dr. Polonsky report having no relevant financial relationships.

A version of this article appeared on Medscape.com.

The Food and Drug Administration has issued voluntary, short-term sodium reduction targets for food manufacturers, chain restaurants, and food service operators for processed, packaged, and prepared foods, with an eye toward reducing diet-related conditions such as heart disease and obesity.

According to the FDA, more than 70% of total sodium intake is from sodium added during food manufacturing and commercial food preparation.

The new targets seek to decrease average sodium intake from approximately 3,400 mg/day to 3,000 mg/day, about a 12% reduction, over the next 2.5 years, acting FDA Commissioner Janet Woodcock, MD, and Susan Mayne, PhD, director of the FDA’s Center for Food Safety and Applied Nutrition, said in joint statement.

Although this reduction keeps the average intake above the recommended limit of 2,300 mg/day for individuals 14 years and older as per the Dietary Guidelines for Americans, “we know that even these modest reductions made slowly over the next few years will substantially decrease diet-related diseases,” they added.

The FDA first proposed recommendations for reducing sodium content in draft guidance released in 2016.

Since, then a number of companies in the food industry have already made changes to sodium content in their products, “which is encouraging, but additional support across all types of foods to help consumers meet recommended sodium limits is needed,” Dr. Woodcock and Dr. Mayne said.

They emphasized that the new guidance represents short-term goals that the food industry should work to meet as soon as possible to help optimize public health.

“We will continue our discussions with the food industry as we monitor the sodium content of the food supply to evaluate progress. In the future, we plan to issue revised, subsequent targets to further lower the sodium content incrementally and continue to help reduce sodium intake,” Dr. Woodcock and Dr. Mayne said.
 

AHA: A good first step that does not go far enough

In a statement, the American Heart Association said the new targets will play “a critical role in helping people across the country achieve healthier levels of sodium and improved well-being overall. These targets will be an important driver to reduce sodium consumption, which can have significant health benefits and lead to lower medical costs.”

“Lowering sodium levels in the food supply would reduce risk of hypertension, heart disease, stroke, heart attack, and death in addition to saving billions of dollars in health care costs over the next decade,” the AHA said.

But the AHA also said lowering sodium intake to 3,000 mg/day is not enough.

“Lowering sodium further to 2,300 mg could prevent an estimated 450,000 cases of cardiovascular disease, gain 2 million quality-adjusted life-years, and save approximately $40 billion in health care costs over a 20-year period,” the AHA said.

The AHA is urging the FDA to “follow [this] action with additional targets to further lower the amount of sodium in the food supply and help people in America attain an appropriate sodium intake.”

A version of this article first appeared on Medscape.com.

The Food and Drug Administration has issued voluntary, short-term sodium reduction targets for food manufacturers, chain restaurants, and food service operators for processed, packaged, and prepared foods, with an eye toward reducing diet-related conditions such as heart disease and obesity.

According to the FDA, more than 70% of total sodium intake is from sodium added during food manufacturing and commercial food preparation.

The new targets seek to decrease average sodium intake from approximately 3,400 mg/day to 3,000 mg/day, about a 12% reduction, over the next 2.5 years, acting FDA Commissioner Janet Woodcock, MD, and Susan Mayne, PhD, director of the FDA’s Center for Food Safety and Applied Nutrition, said in joint statement.

Although this reduction keeps the average intake above the recommended limit of 2,300 mg/day for individuals 14 years and older as per the Dietary Guidelines for Americans, “we know that even these modest reductions made slowly over the next few years will substantially decrease diet-related diseases,” they added.

The FDA first proposed recommendations for reducing sodium content in draft guidance released in 2016.

Since, then a number of companies in the food industry have already made changes to sodium content in their products, “which is encouraging, but additional support across all types of foods to help consumers meet recommended sodium limits is needed,” Dr. Woodcock and Dr. Mayne said.

They emphasized that the new guidance represents short-term goals that the food industry should work to meet as soon as possible to help optimize public health.

“We will continue our discussions with the food industry as we monitor the sodium content of the food supply to evaluate progress. In the future, we plan to issue revised, subsequent targets to further lower the sodium content incrementally and continue to help reduce sodium intake,” Dr. Woodcock and Dr. Mayne said.
 

AHA: A good first step that does not go far enough

In a statement, the American Heart Association said the new targets will play “a critical role in helping people across the country achieve healthier levels of sodium and improved well-being overall. These targets will be an important driver to reduce sodium consumption, which can have significant health benefits and lead to lower medical costs.”

“Lowering sodium levels in the food supply would reduce risk of hypertension, heart disease, stroke, heart attack, and death in addition to saving billions of dollars in health care costs over the next decade,” the AHA said.

But the AHA also said lowering sodium intake to 3,000 mg/day is not enough.

“Lowering sodium further to 2,300 mg could prevent an estimated 450,000 cases of cardiovascular disease, gain 2 million quality-adjusted life-years, and save approximately $40 billion in health care costs over a 20-year period,” the AHA said.

The AHA is urging the FDA to “follow [this] action with additional targets to further lower the amount of sodium in the food supply and help people in America attain an appropriate sodium intake.”

A version of this article first appeared on Medscape.com.

The Food and Drug Administration has issued voluntary, short-term sodium reduction targets for food manufacturers, chain restaurants, and food service operators for processed, packaged, and prepared foods, with an eye toward reducing diet-related conditions such as heart disease and obesity.

According to the FDA, more than 70% of total sodium intake is from sodium added during food manufacturing and commercial food preparation.

The new targets seek to decrease average sodium intake from approximately 3,400 mg/day to 3,000 mg/day, about a 12% reduction, over the next 2.5 years, acting FDA Commissioner Janet Woodcock, MD, and Susan Mayne, PhD, director of the FDA’s Center for Food Safety and Applied Nutrition, said in joint statement.

Although this reduction keeps the average intake above the recommended limit of 2,300 mg/day for individuals 14 years and older as per the Dietary Guidelines for Americans, “we know that even these modest reductions made slowly over the next few years will substantially decrease diet-related diseases,” they added.

The FDA first proposed recommendations for reducing sodium content in draft guidance released in 2016.

Since, then a number of companies in the food industry have already made changes to sodium content in their products, “which is encouraging, but additional support across all types of foods to help consumers meet recommended sodium limits is needed,” Dr. Woodcock and Dr. Mayne said.

They emphasized that the new guidance represents short-term goals that the food industry should work to meet as soon as possible to help optimize public health.

“We will continue our discussions with the food industry as we monitor the sodium content of the food supply to evaluate progress. In the future, we plan to issue revised, subsequent targets to further lower the sodium content incrementally and continue to help reduce sodium intake,” Dr. Woodcock and Dr. Mayne said.
 

AHA: A good first step that does not go far enough

In a statement, the American Heart Association said the new targets will play “a critical role in helping people across the country achieve healthier levels of sodium and improved well-being overall. These targets will be an important driver to reduce sodium consumption, which can have significant health benefits and lead to lower medical costs.”

“Lowering sodium levels in the food supply would reduce risk of hypertension, heart disease, stroke, heart attack, and death in addition to saving billions of dollars in health care costs over the next decade,” the AHA said.

But the AHA also said lowering sodium intake to 3,000 mg/day is not enough.

“Lowering sodium further to 2,300 mg could prevent an estimated 450,000 cases of cardiovascular disease, gain 2 million quality-adjusted life-years, and save approximately $40 billion in health care costs over a 20-year period,” the AHA said.

The AHA is urging the FDA to “follow [this] action with additional targets to further lower the amount of sodium in the food supply and help people in America attain an appropriate sodium intake.”

A version of this article first appeared on Medscape.com.

Discovery of substantial atrial fibrillation (AFib) is usually an indication to start oral anticoagulation (OAC) for stroke prevention, but it’s far from settled whether such AFib is actually a direct cause of thromboembolic stroke. And that has implications for whether patients with occasional bouts of the arrhythmia need to be on continuous OAC.  

It’s possible that some with infrequent paroxysmal AFib can get away with OAC maintained only about as long as the arrhythmia persists, and then go off the drugs, say researchers based on their study, which, they caution, would need the support of prospective trials before such a strategy could be considered.

But importantly, in their patients who had been continuously monitored by their cardiac implantable electronic devices (CIEDs) prior to experiencing a stroke, the 30-day risk of that stroke more than tripled if their AFib burden on 1 day reached at least 5-6 hours. The risk jumped especially high within the first few days after accumulating that amount of AFib in a day, but then fell off sharply over the next few days.

Based on the study, “Your risk of stroke goes up acutely when you have an episode of AFib, and it decreases rapidly, back to baseline – certainly by 30 days and it looked like in our data by 5 days,” Daniel E. Singer, MD, of Massachusetts General Hospital, Boston, said in an interview.

Increasingly, he noted, “there’s a widespread belief that AFib is a risk marker, not a causal risk factor.” In that scenario, most embolic strokes are caused by thrombi formed as a result of an atrial myopathy, characterized by fibrosis and inflammation, that also happens to trigger AFib.

But the current findings are, “from a mechanistic point of view, very much in favor of AFib being a causal risk factor, acutely raising the risk of stroke,” said Dr. Singer, who is lead author on the analysis published online Sept. 29 in JAMA Cardiology.

Some studies have “shown that anticoagulants seem to lower stroke risk even in patients without atrial fib, and even from sources not likely to be coming from the atrium,” Mintu P. Turakhia, MD, of Stanford (Calif.) University, Palo Alto, said in an interview. Collectively they point to “atrial fibrillation as a cause of and a noncausal marker for stroke.”

For example, Dr. Turakhia pointed out in an editorial accompanying the current report that stroke in patients with CIEDs “may occur during prolonged periods of sinus rhythm.”

The current study, he said in an interview, doesn’t preclude atrial myopathy as one direct cause of stroke-associated thrombus, because probably both the myopathy and AFib can be culprits. Still, AFib itself it may bear more responsibility for strokes in patients with fewer competing risks for stroke.

In such patients at lower vascular risk, who may have a CHA2DS2-VASc score of only 1 or 2, for example, “AFib can become a more important cause” of ischemic stroke, Dr. Turakhia said. That’s when AFib is more likely to be temporally related to stroke as the likely culprit, the mechanism addressed by Dr. Singer and associates.

“I think we’re all trying to grapple with what the truth is,” Dr. Singer observed. Still, the current study was unusual for primarily looking at the temporal relationship between AFib and stroke, rather than stroke risk. “And once again, as we found in our earlier study, but now a much larger study, it’s a tight relationship.”

Based on the current results, he said, the risk is “high when you have AFib, and it decreases very rapidly after the AFib is over.” And, “it takes multiple hours of AFib to raise stroke risk.” Inclusion in the analysis required accumulation of at least 5.5 hours of AFib on at least 1 day in a month, the cut point at which stroke risk started to climb significantly in an earlier trial.  

In the current analysis, however, the 30-day odds ratio for stroke was a nonsignificant 2.75 for an AFib burden of 6-23 hours in a day and jumped to a significant 5.0 for a burden in excess of 23 hours in a day. “That’s a lot of AFib” before the risk actually goes up, and supports AFib as causative, Dr. Singer said. If it were the myopathy itself triggering stroke in these particular patients, the risk would be ongoing and not subject to a threshold of AFib burden.
 

Implications for noncontinuous OAC

“The hope is that there are people who have very little AFib: They may have several hours, and then they have nothing for 6 months. Do they have to be anticoagulated or not?” Dr. Singer asked.

“If you believe the risk-marker story, you might say they have to be anticoagulated. But if you believe our results, you would certainly think there’s a good chance they don’t have to be anticoagulated,” he said.

“So it is logical to think, if you have the right people and continuous monitoring, that you could have time-delimited anticoagulation.” That is, patients might start right away on a direct OAC once reaching the AFib threshold in a day, Dr. Singer said, “going on and off anticoagulants in parallel with their episodes of AFib.”

The strategy wouldn’t be feasible in patients who often experience AFib, Dr. Singer noted, “but it might work for people who have infrequent paroxysmal AFib.” It certainly would first have to be tested in prospective trials, he said. Such trials would be more practical than ever to carry out given the growing availability of continuous AFib monitoring by wearables.

“We need a trial to make the case whether it’s safe or not,” Dr. Turakhia said of such a rhythm-guided approach to OAC for AFib. The population to start with, he said, would be patients with paroxysmal AFib and low CHA2DS2-VASc scores. “If you think CHA2DS2-VASc as an integrated score of vascular risk, such patients would have a lot fewer reasons to have strokes. And if they do have a stroke, it’s more reasonable to assume that it’s likely caused by atrial fib and not just a marker.”

Importantly, such a strategy could well be safer than continuous OAC for some patients – those at the lowest vascular risk and with the most occasional AFib and lowest AFib burden “who are otherwise doing fine,” Dr. Turakhia said. In such patients on continuous OAC, he proposed, the risks of bleeding and intracranial hemorrhage could potentially exceed the expected degree of protection from ischemic events.
 

Discordant periods of AFib burden

Dr. Singer and his colleagues linked a national electronic health record database with Medtronic CareLink records covering 10 years to identify 891 patients who experienced an ischemic stroke preceded by at least 120 days of continuous heart-rhythm monitoring.

The patients were then categorized by their pattern of AFib, if any, within each of two prestroke periods: the most recent 30 days, which was the test period, and the preceding 91-120 days, the control period.

The analysis then excluded any patients who reached an AFib-burden threshold of at least 5.5 hours on any day during both the test and control periods, and those who did not attain that threshold in either period.

“The ones who had AFib in both periods mostly had permanent AFib, and ones that didn’t have AFib in either period mostly were in sinus rhythm,” Dr. Singer said. It was “close to 100%” in both cases.

Those exclusions left 66 patients, 7.4% of the total, who reached the AFib-burden threshold on at least 1 day during either the test or control periods, but not both. They included 52 and 14 patients, respectively, with “discordant” periods, that is, at least that burden of AFib in a day during either the test or control period, but not both.

Comparing AFib burden at test versus control periods among patients for whom the two periods were discordant yielded an OR for stroke of 3.71 (95% confidence interval, 2.06-6.70).

Stroke risk levels were not evenly spread throughout the 24-hour periods that met the AFib-burden threshold or the 30 days preceding the patients’ strokes. The OR for stroke was 5.00 (95% CI, 2.62-9.55) during days 1-5 following the day in which the AFib-burden threshold was met. And it was 5.00 (95% CI, 2.08-12.01) over 30 days if the AFib burden exceeded 23 hours on any day of the test period.

The study’s case-crossover design, in which each patient served as their own control, is one of its advantages, Dr. Singer observed. Most patient features, including CHA2DS2-VASc score and comorbidities, did not change appreciably from earliest to the latest 30-day period, which strengthens the comparison of the two because “you don’t have to worry about long-term confounding.”

Dr. Singer was supported by the Eliot B. and Edith C. Shoolman fund of the Massachusetts General Hospital. He discloses receiving grants from Boehringer Ingelheim and Bristol-Myers Squibb; personal fees from Boehringer Ingelheim, Bristol-Myers Squibb, Fitbit, Johnson & Johnson, Merck, and Pfizer; and royalties from UpToDate.

Dr. Turakhia discloses personal fees from Medtronic, Abbott, Sanofi, Pfizer, Myokardia, Johnson & Johnson, Milestone Pharmaceuticals, InCarda Therapeutics, 100Plus, Forward Pharma, and AliveCor; and grants from Bristol-Myers Squibb, the American Heart Association, Apple, and Bayer.

A version of this article first appeared on Medscape.com.

Discovery of substantial atrial fibrillation (AFib) is usually an indication to start oral anticoagulation (OAC) for stroke prevention, but it’s far from settled whether such AFib is actually a direct cause of thromboembolic stroke. And that has implications for whether patients with occasional bouts of the arrhythmia need to be on continuous OAC.  

It’s possible that some with infrequent paroxysmal AFib can get away with OAC maintained only about as long as the arrhythmia persists, and then go off the drugs, say researchers based on their study, which, they caution, would need the support of prospective trials before such a strategy could be considered.

But importantly, in their patients who had been continuously monitored by their cardiac implantable electronic devices (CIEDs) prior to experiencing a stroke, the 30-day risk of that stroke more than tripled if their AFib burden on 1 day reached at least 5-6 hours. The risk jumped especially high within the first few days after accumulating that amount of AFib in a day, but then fell off sharply over the next few days.

Based on the study, “Your risk of stroke goes up acutely when you have an episode of AFib, and it decreases rapidly, back to baseline – certainly by 30 days and it looked like in our data by 5 days,” Daniel E. Singer, MD, of Massachusetts General Hospital, Boston, said in an interview.

Increasingly, he noted, “there’s a widespread belief that AFib is a risk marker, not a causal risk factor.” In that scenario, most embolic strokes are caused by thrombi formed as a result of an atrial myopathy, characterized by fibrosis and inflammation, that also happens to trigger AFib.

But the current findings are, “from a mechanistic point of view, very much in favor of AFib being a causal risk factor, acutely raising the risk of stroke,” said Dr. Singer, who is lead author on the analysis published online Sept. 29 in JAMA Cardiology.

Some studies have “shown that anticoagulants seem to lower stroke risk even in patients without atrial fib, and even from sources not likely to be coming from the atrium,” Mintu P. Turakhia, MD, of Stanford (Calif.) University, Palo Alto, said in an interview. Collectively they point to “atrial fibrillation as a cause of and a noncausal marker for stroke.”

For example, Dr. Turakhia pointed out in an editorial accompanying the current report that stroke in patients with CIEDs “may occur during prolonged periods of sinus rhythm.”

The current study, he said in an interview, doesn’t preclude atrial myopathy as one direct cause of stroke-associated thrombus, because probably both the myopathy and AFib can be culprits. Still, AFib itself it may bear more responsibility for strokes in patients with fewer competing risks for stroke.

In such patients at lower vascular risk, who may have a CHA2DS2-VASc score of only 1 or 2, for example, “AFib can become a more important cause” of ischemic stroke, Dr. Turakhia said. That’s when AFib is more likely to be temporally related to stroke as the likely culprit, the mechanism addressed by Dr. Singer and associates.

“I think we’re all trying to grapple with what the truth is,” Dr. Singer observed. Still, the current study was unusual for primarily looking at the temporal relationship between AFib and stroke, rather than stroke risk. “And once again, as we found in our earlier study, but now a much larger study, it’s a tight relationship.”

Based on the current results, he said, the risk is “high when you have AFib, and it decreases very rapidly after the AFib is over.” And, “it takes multiple hours of AFib to raise stroke risk.” Inclusion in the analysis required accumulation of at least 5.5 hours of AFib on at least 1 day in a month, the cut point at which stroke risk started to climb significantly in an earlier trial.  

In the current analysis, however, the 30-day odds ratio for stroke was a nonsignificant 2.75 for an AFib burden of 6-23 hours in a day and jumped to a significant 5.0 for a burden in excess of 23 hours in a day. “That’s a lot of AFib” before the risk actually goes up, and supports AFib as causative, Dr. Singer said. If it were the myopathy itself triggering stroke in these particular patients, the risk would be ongoing and not subject to a threshold of AFib burden.
 

Implications for noncontinuous OAC

“The hope is that there are people who have very little AFib: They may have several hours, and then they have nothing for 6 months. Do they have to be anticoagulated or not?” Dr. Singer asked.

“If you believe the risk-marker story, you might say they have to be anticoagulated. But if you believe our results, you would certainly think there’s a good chance they don’t have to be anticoagulated,” he said.

“So it is logical to think, if you have the right people and continuous monitoring, that you could have time-delimited anticoagulation.” That is, patients might start right away on a direct OAC once reaching the AFib threshold in a day, Dr. Singer said, “going on and off anticoagulants in parallel with their episodes of AFib.”

The strategy wouldn’t be feasible in patients who often experience AFib, Dr. Singer noted, “but it might work for people who have infrequent paroxysmal AFib.” It certainly would first have to be tested in prospective trials, he said. Such trials would be more practical than ever to carry out given the growing availability of continuous AFib monitoring by wearables.

“We need a trial to make the case whether it’s safe or not,” Dr. Turakhia said of such a rhythm-guided approach to OAC for AFib. The population to start with, he said, would be patients with paroxysmal AFib and low CHA2DS2-VASc scores. “If you think CHA2DS2-VASc as an integrated score of vascular risk, such patients would have a lot fewer reasons to have strokes. And if they do have a stroke, it’s more reasonable to assume that it’s likely caused by atrial fib and not just a marker.”

Importantly, such a strategy could well be safer than continuous OAC for some patients – those at the lowest vascular risk and with the most occasional AFib and lowest AFib burden “who are otherwise doing fine,” Dr. Turakhia said. In such patients on continuous OAC, he proposed, the risks of bleeding and intracranial hemorrhage could potentially exceed the expected degree of protection from ischemic events.
 

Discordant periods of AFib burden

Dr. Singer and his colleagues linked a national electronic health record database with Medtronic CareLink records covering 10 years to identify 891 patients who experienced an ischemic stroke preceded by at least 120 days of continuous heart-rhythm monitoring.

The patients were then categorized by their pattern of AFib, if any, within each of two prestroke periods: the most recent 30 days, which was the test period, and the preceding 91-120 days, the control period.

The analysis then excluded any patients who reached an AFib-burden threshold of at least 5.5 hours on any day during both the test and control periods, and those who did not attain that threshold in either period.

“The ones who had AFib in both periods mostly had permanent AFib, and ones that didn’t have AFib in either period mostly were in sinus rhythm,” Dr. Singer said. It was “close to 100%” in both cases.

Those exclusions left 66 patients, 7.4% of the total, who reached the AFib-burden threshold on at least 1 day during either the test or control periods, but not both. They included 52 and 14 patients, respectively, with “discordant” periods, that is, at least that burden of AFib in a day during either the test or control period, but not both.

Comparing AFib burden at test versus control periods among patients for whom the two periods were discordant yielded an OR for stroke of 3.71 (95% confidence interval, 2.06-6.70).

Stroke risk levels were not evenly spread throughout the 24-hour periods that met the AFib-burden threshold or the 30 days preceding the patients’ strokes. The OR for stroke was 5.00 (95% CI, 2.62-9.55) during days 1-5 following the day in which the AFib-burden threshold was met. And it was 5.00 (95% CI, 2.08-12.01) over 30 days if the AFib burden exceeded 23 hours on any day of the test period.

The study’s case-crossover design, in which each patient served as their own control, is one of its advantages, Dr. Singer observed. Most patient features, including CHA2DS2-VASc score and comorbidities, did not change appreciably from earliest to the latest 30-day period, which strengthens the comparison of the two because “you don’t have to worry about long-term confounding.”

Dr. Singer was supported by the Eliot B. and Edith C. Shoolman fund of the Massachusetts General Hospital. He discloses receiving grants from Boehringer Ingelheim and Bristol-Myers Squibb; personal fees from Boehringer Ingelheim, Bristol-Myers Squibb, Fitbit, Johnson & Johnson, Merck, and Pfizer; and royalties from UpToDate.

Dr. Turakhia discloses personal fees from Medtronic, Abbott, Sanofi, Pfizer, Myokardia, Johnson & Johnson, Milestone Pharmaceuticals, InCarda Therapeutics, 100Plus, Forward Pharma, and AliveCor; and grants from Bristol-Myers Squibb, the American Heart Association, Apple, and Bayer.

A version of this article first appeared on Medscape.com.

Discovery of substantial atrial fibrillation (AFib) is usually an indication to start oral anticoagulation (OAC) for stroke prevention, but it’s far from settled whether such AFib is actually a direct cause of thromboembolic stroke. And that has implications for whether patients with occasional bouts of the arrhythmia need to be on continuous OAC.  

It’s possible that some with infrequent paroxysmal AFib can get away with OAC maintained only about as long as the arrhythmia persists, and then go off the drugs, say researchers based on their study, which, they caution, would need the support of prospective trials before such a strategy could be considered.

But importantly, in their patients who had been continuously monitored by their cardiac implantable electronic devices (CIEDs) prior to experiencing a stroke, the 30-day risk of that stroke more than tripled if their AFib burden on 1 day reached at least 5-6 hours. The risk jumped especially high within the first few days after accumulating that amount of AFib in a day, but then fell off sharply over the next few days.

Based on the study, “Your risk of stroke goes up acutely when you have an episode of AFib, and it decreases rapidly, back to baseline – certainly by 30 days and it looked like in our data by 5 days,” Daniel E. Singer, MD, of Massachusetts General Hospital, Boston, said in an interview.

Increasingly, he noted, “there’s a widespread belief that AFib is a risk marker, not a causal risk factor.” In that scenario, most embolic strokes are caused by thrombi formed as a result of an atrial myopathy, characterized by fibrosis and inflammation, that also happens to trigger AFib.

But the current findings are, “from a mechanistic point of view, very much in favor of AFib being a causal risk factor, acutely raising the risk of stroke,” said Dr. Singer, who is lead author on the analysis published online Sept. 29 in JAMA Cardiology.

Some studies have “shown that anticoagulants seem to lower stroke risk even in patients without atrial fib, and even from sources not likely to be coming from the atrium,” Mintu P. Turakhia, MD, of Stanford (Calif.) University, Palo Alto, said in an interview. Collectively they point to “atrial fibrillation as a cause of and a noncausal marker for stroke.”

For example, Dr. Turakhia pointed out in an editorial accompanying the current report that stroke in patients with CIEDs “may occur during prolonged periods of sinus rhythm.”

The current study, he said in an interview, doesn’t preclude atrial myopathy as one direct cause of stroke-associated thrombus, because probably both the myopathy and AFib can be culprits. Still, AFib itself it may bear more responsibility for strokes in patients with fewer competing risks for stroke.

In such patients at lower vascular risk, who may have a CHA2DS2-VASc score of only 1 or 2, for example, “AFib can become a more important cause” of ischemic stroke, Dr. Turakhia said. That’s when AFib is more likely to be temporally related to stroke as the likely culprit, the mechanism addressed by Dr. Singer and associates.

“I think we’re all trying to grapple with what the truth is,” Dr. Singer observed. Still, the current study was unusual for primarily looking at the temporal relationship between AFib and stroke, rather than stroke risk. “And once again, as we found in our earlier study, but now a much larger study, it’s a tight relationship.”

Based on the current results, he said, the risk is “high when you have AFib, and it decreases very rapidly after the AFib is over.” And, “it takes multiple hours of AFib to raise stroke risk.” Inclusion in the analysis required accumulation of at least 5.5 hours of AFib on at least 1 day in a month, the cut point at which stroke risk started to climb significantly in an earlier trial.  

In the current analysis, however, the 30-day odds ratio for stroke was a nonsignificant 2.75 for an AFib burden of 6-23 hours in a day and jumped to a significant 5.0 for a burden in excess of 23 hours in a day. “That’s a lot of AFib” before the risk actually goes up, and supports AFib as causative, Dr. Singer said. If it were the myopathy itself triggering stroke in these particular patients, the risk would be ongoing and not subject to a threshold of AFib burden.
 

Implications for noncontinuous OAC

“The hope is that there are people who have very little AFib: They may have several hours, and then they have nothing for 6 months. Do they have to be anticoagulated or not?” Dr. Singer asked.

“If you believe the risk-marker story, you might say they have to be anticoagulated. But if you believe our results, you would certainly think there’s a good chance they don’t have to be anticoagulated,” he said.

“So it is logical to think, if you have the right people and continuous monitoring, that you could have time-delimited anticoagulation.” That is, patients might start right away on a direct OAC once reaching the AFib threshold in a day, Dr. Singer said, “going on and off anticoagulants in parallel with their episodes of AFib.”

The strategy wouldn’t be feasible in patients who often experience AFib, Dr. Singer noted, “but it might work for people who have infrequent paroxysmal AFib.” It certainly would first have to be tested in prospective trials, he said. Such trials would be more practical than ever to carry out given the growing availability of continuous AFib monitoring by wearables.

“We need a trial to make the case whether it’s safe or not,” Dr. Turakhia said of such a rhythm-guided approach to OAC for AFib. The population to start with, he said, would be patients with paroxysmal AFib and low CHA2DS2-VASc scores. “If you think CHA2DS2-VASc as an integrated score of vascular risk, such patients would have a lot fewer reasons to have strokes. And if they do have a stroke, it’s more reasonable to assume that it’s likely caused by atrial fib and not just a marker.”

Importantly, such a strategy could well be safer than continuous OAC for some patients – those at the lowest vascular risk and with the most occasional AFib and lowest AFib burden “who are otherwise doing fine,” Dr. Turakhia said. In such patients on continuous OAC, he proposed, the risks of bleeding and intracranial hemorrhage could potentially exceed the expected degree of protection from ischemic events.
 

Discordant periods of AFib burden

Dr. Singer and his colleagues linked a national electronic health record database with Medtronic CareLink records covering 10 years to identify 891 patients who experienced an ischemic stroke preceded by at least 120 days of continuous heart-rhythm monitoring.

The patients were then categorized by their pattern of AFib, if any, within each of two prestroke periods: the most recent 30 days, which was the test period, and the preceding 91-120 days, the control period.

The analysis then excluded any patients who reached an AFib-burden threshold of at least 5.5 hours on any day during both the test and control periods, and those who did not attain that threshold in either period.

“The ones who had AFib in both periods mostly had permanent AFib, and ones that didn’t have AFib in either period mostly were in sinus rhythm,” Dr. Singer said. It was “close to 100%” in both cases.

Those exclusions left 66 patients, 7.4% of the total, who reached the AFib-burden threshold on at least 1 day during either the test or control periods, but not both. They included 52 and 14 patients, respectively, with “discordant” periods, that is, at least that burden of AFib in a day during either the test or control period, but not both.

Comparing AFib burden at test versus control periods among patients for whom the two periods were discordant yielded an OR for stroke of 3.71 (95% confidence interval, 2.06-6.70).

Stroke risk levels were not evenly spread throughout the 24-hour periods that met the AFib-burden threshold or the 30 days preceding the patients’ strokes. The OR for stroke was 5.00 (95% CI, 2.62-9.55) during days 1-5 following the day in which the AFib-burden threshold was met. And it was 5.00 (95% CI, 2.08-12.01) over 30 days if the AFib burden exceeded 23 hours on any day of the test period.

The study’s case-crossover design, in which each patient served as their own control, is one of its advantages, Dr. Singer observed. Most patient features, including CHA2DS2-VASc score and comorbidities, did not change appreciably from earliest to the latest 30-day period, which strengthens the comparison of the two because “you don’t have to worry about long-term confounding.”

Dr. Singer was supported by the Eliot B. and Edith C. Shoolman fund of the Massachusetts General Hospital. He discloses receiving grants from Boehringer Ingelheim and Bristol-Myers Squibb; personal fees from Boehringer Ingelheim, Bristol-Myers Squibb, Fitbit, Johnson & Johnson, Merck, and Pfizer; and royalties from UpToDate.

Dr. Turakhia discloses personal fees from Medtronic, Abbott, Sanofi, Pfizer, Myokardia, Johnson & Johnson, Milestone Pharmaceuticals, InCarda Therapeutics, 100Plus, Forward Pharma, and AliveCor; and grants from Bristol-Myers Squibb, the American Heart Association, Apple, and Bayer.

A version of this article first appeared on Medscape.com.