User login
Higher endovascular thrombectomy volumes yield better stroke outcomes
LOS ANGELES – Higher case volumes matter for getting better outcomes in acute ischemic stroke patients treated with endovascular thrombectomy, according to data from more than 13,000 Medicare patients treated during 2016 and 2017.
That’s hardly surprising, given that it’s consistent with what’s already been reported for several other types of endovascular and transcatheter procedures: The more cases a center or individual proceduralist performs, the better their patients do. Routine use of endovascular thrombectomy to treat selected acute ischemic stroke patients is a new-enough paradigm that until now few reports have come out that looked at this issue (Stroke. 2019 May;50[5]:1178-83).
The new analysis of Medicare data “is one of the first contemporary studies of the volume-outcome relationship in endovascular thrombectomy,” Laura K. Stein, MD, said at the International Stroke Conference sponsored by the American Heart Association. The analysis showed that, when the researchers adjusted the Medicare data to better reflect overall case volumes (Medicare patients represent just 59% of all endovascular thrombectomies performed on U.S. acute ischemic stroke patients), the minimum case number for a stroke center to have statistically better in-hospital survival than lower volume centers was 24 cases/year, and 29 cases/year to have a statistically significant higher rate of “good” outcomes than lower-volume centers, reported Dr. Stein, a stroke neurologist with the Mount Sinai Health System in New York. For individual proceduralists, the minimum, adjusted case number to have statistically better acute patient survival was 4 cases/year, and 19 cases/year to have a statistically better rate of good outcomes.
For this analysis, good outcomes were defined as cases when patients left the hospital following their acute care and returned home with either self care or a home health care service, and also patients discharged to rehabilitation. “Bad” outcomes for this analysis were discharges to a skilled nursing facility or hospice, as well as patients who died during their acute hospitalization.
The analyses also showed no plateau to the volume effect for any of the four parameters examined: in-hospital mortality by center and by proceduralist, and the rates of good outcomes by center and by proceduralist. For each of these measures, as case volume increased above the minimum number needed to produce statistically better outcomes, the rate of good outcomes continued to steadily rise and acute mortality continued to steadily fall.
The study run by Dr. Stein and associates used data collected by the Center for Medicare & Medicaid Services on 13,311 Medicare patients who underwent endovascular thrombectomy for acute ischemic stroke at any of 641 U.S. hospitals and received treatment from any of 2,754 thrombectomy proceduralists. Outcomes rated as good occurred in 56% of the patients. The statistical adjustments that the researchers applied to calculate the incremental effect of increasing case volume took into account the variables of patient age, sex, and comorbidities measured by the Charlson Comorbidity Index.
The analysis also showed that, during this 2-year period, the average number of endovascular thrombectomy cases among Medicare patients was just under 21 cases per center, with a range of 1-160 cases; for individual proceduralists, the average was just under 5 cases, with a range of 1-82 cases.
The 19 case/year volume minimum that the analysis identified for an individual proceduralist to have a statistically significant higher rate of good outcomes, compared with lower-volume proceduralists, came close to the 15 cases/year minimum set by the Joint Commission in 2019 for individual operators at centers seeking accreditation from the Joint Commission as either a Thrombectomy-Capable Stroke Center or a Comprehensive Stroke Center. The CMS has not yet set thrombectomy case-load requirements for centers or operators to qualify for Medicare reimbursements, although CMS has set such standards for other endovascular procedures, such as transcatheter aortic valve replacement. When setting such standards, CMS has cited its need to balance the better outcomes produced by higher-volume centers against a societal interest in facilitating access to vital medical services, a balance that Dr. Stein also highlighted in her talk.
“We want to optimize access as well as outcomes for every patient,” she said. “These data support certification volume standards,” but they are “in no way an argument for limiting access based on volume.”
Dr. Stein had no disclosures.
SOURCE: Stein LK et al. ISC 2020, Abstract LB11.
The results reported by Dr. Stein raise issues about balancing the access to certain therapies with the outcomes of those therapies. Having procedures like endovascular thrombectomy for acute ischemic stroke done primarily at high-volume centers might improve procedural outcomes, but having more centers offering this treatment across wider geographical areas would make this treatment more broadly available to more people.
For endovascular thrombectomy, center volume and experience may be much more important than proceduralist volume because having a smoothly functioning system in place is so important for rapid stroke assessment and treatment. It’s also important for programs to provide experienced and comprehensive postthrombectomy care. Success in endovascular thrombectomy involves much more than just taking a clot out. It means quickly and smoothly moving patients through the steps that precede thrombectomy and then following the intervention with a range of services that optimize recovery.
Ashutosh P. Jadhav, MD, PhD , is director of the comprehensive stroke center at the University of Pittsburgh. He had no relevant disclosures. He made these comments in an interview.
The results reported by Dr. Stein raise issues about balancing the access to certain therapies with the outcomes of those therapies. Having procedures like endovascular thrombectomy for acute ischemic stroke done primarily at high-volume centers might improve procedural outcomes, but having more centers offering this treatment across wider geographical areas would make this treatment more broadly available to more people.
For endovascular thrombectomy, center volume and experience may be much more important than proceduralist volume because having a smoothly functioning system in place is so important for rapid stroke assessment and treatment. It’s also important for programs to provide experienced and comprehensive postthrombectomy care. Success in endovascular thrombectomy involves much more than just taking a clot out. It means quickly and smoothly moving patients through the steps that precede thrombectomy and then following the intervention with a range of services that optimize recovery.
Ashutosh P. Jadhav, MD, PhD , is director of the comprehensive stroke center at the University of Pittsburgh. He had no relevant disclosures. He made these comments in an interview.
The results reported by Dr. Stein raise issues about balancing the access to certain therapies with the outcomes of those therapies. Having procedures like endovascular thrombectomy for acute ischemic stroke done primarily at high-volume centers might improve procedural outcomes, but having more centers offering this treatment across wider geographical areas would make this treatment more broadly available to more people.
For endovascular thrombectomy, center volume and experience may be much more important than proceduralist volume because having a smoothly functioning system in place is so important for rapid stroke assessment and treatment. It’s also important for programs to provide experienced and comprehensive postthrombectomy care. Success in endovascular thrombectomy involves much more than just taking a clot out. It means quickly and smoothly moving patients through the steps that precede thrombectomy and then following the intervention with a range of services that optimize recovery.
Ashutosh P. Jadhav, MD, PhD , is director of the comprehensive stroke center at the University of Pittsburgh. He had no relevant disclosures. He made these comments in an interview.
LOS ANGELES – Higher case volumes matter for getting better outcomes in acute ischemic stroke patients treated with endovascular thrombectomy, according to data from more than 13,000 Medicare patients treated during 2016 and 2017.
That’s hardly surprising, given that it’s consistent with what’s already been reported for several other types of endovascular and transcatheter procedures: The more cases a center or individual proceduralist performs, the better their patients do. Routine use of endovascular thrombectomy to treat selected acute ischemic stroke patients is a new-enough paradigm that until now few reports have come out that looked at this issue (Stroke. 2019 May;50[5]:1178-83).
The new analysis of Medicare data “is one of the first contemporary studies of the volume-outcome relationship in endovascular thrombectomy,” Laura K. Stein, MD, said at the International Stroke Conference sponsored by the American Heart Association. The analysis showed that, when the researchers adjusted the Medicare data to better reflect overall case volumes (Medicare patients represent just 59% of all endovascular thrombectomies performed on U.S. acute ischemic stroke patients), the minimum case number for a stroke center to have statistically better in-hospital survival than lower volume centers was 24 cases/year, and 29 cases/year to have a statistically significant higher rate of “good” outcomes than lower-volume centers, reported Dr. Stein, a stroke neurologist with the Mount Sinai Health System in New York. For individual proceduralists, the minimum, adjusted case number to have statistically better acute patient survival was 4 cases/year, and 19 cases/year to have a statistically better rate of good outcomes.
For this analysis, good outcomes were defined as cases when patients left the hospital following their acute care and returned home with either self care or a home health care service, and also patients discharged to rehabilitation. “Bad” outcomes for this analysis were discharges to a skilled nursing facility or hospice, as well as patients who died during their acute hospitalization.
The analyses also showed no plateau to the volume effect for any of the four parameters examined: in-hospital mortality by center and by proceduralist, and the rates of good outcomes by center and by proceduralist. For each of these measures, as case volume increased above the minimum number needed to produce statistically better outcomes, the rate of good outcomes continued to steadily rise and acute mortality continued to steadily fall.
The study run by Dr. Stein and associates used data collected by the Center for Medicare & Medicaid Services on 13,311 Medicare patients who underwent endovascular thrombectomy for acute ischemic stroke at any of 641 U.S. hospitals and received treatment from any of 2,754 thrombectomy proceduralists. Outcomes rated as good occurred in 56% of the patients. The statistical adjustments that the researchers applied to calculate the incremental effect of increasing case volume took into account the variables of patient age, sex, and comorbidities measured by the Charlson Comorbidity Index.
The analysis also showed that, during this 2-year period, the average number of endovascular thrombectomy cases among Medicare patients was just under 21 cases per center, with a range of 1-160 cases; for individual proceduralists, the average was just under 5 cases, with a range of 1-82 cases.
The 19 case/year volume minimum that the analysis identified for an individual proceduralist to have a statistically significant higher rate of good outcomes, compared with lower-volume proceduralists, came close to the 15 cases/year minimum set by the Joint Commission in 2019 for individual operators at centers seeking accreditation from the Joint Commission as either a Thrombectomy-Capable Stroke Center or a Comprehensive Stroke Center. The CMS has not yet set thrombectomy case-load requirements for centers or operators to qualify for Medicare reimbursements, although CMS has set such standards for other endovascular procedures, such as transcatheter aortic valve replacement. When setting such standards, CMS has cited its need to balance the better outcomes produced by higher-volume centers against a societal interest in facilitating access to vital medical services, a balance that Dr. Stein also highlighted in her talk.
“We want to optimize access as well as outcomes for every patient,” she said. “These data support certification volume standards,” but they are “in no way an argument for limiting access based on volume.”
Dr. Stein had no disclosures.
SOURCE: Stein LK et al. ISC 2020, Abstract LB11.
LOS ANGELES – Higher case volumes matter for getting better outcomes in acute ischemic stroke patients treated with endovascular thrombectomy, according to data from more than 13,000 Medicare patients treated during 2016 and 2017.
That’s hardly surprising, given that it’s consistent with what’s already been reported for several other types of endovascular and transcatheter procedures: The more cases a center or individual proceduralist performs, the better their patients do. Routine use of endovascular thrombectomy to treat selected acute ischemic stroke patients is a new-enough paradigm that until now few reports have come out that looked at this issue (Stroke. 2019 May;50[5]:1178-83).
The new analysis of Medicare data “is one of the first contemporary studies of the volume-outcome relationship in endovascular thrombectomy,” Laura K. Stein, MD, said at the International Stroke Conference sponsored by the American Heart Association. The analysis showed that, when the researchers adjusted the Medicare data to better reflect overall case volumes (Medicare patients represent just 59% of all endovascular thrombectomies performed on U.S. acute ischemic stroke patients), the minimum case number for a stroke center to have statistically better in-hospital survival than lower volume centers was 24 cases/year, and 29 cases/year to have a statistically significant higher rate of “good” outcomes than lower-volume centers, reported Dr. Stein, a stroke neurologist with the Mount Sinai Health System in New York. For individual proceduralists, the minimum, adjusted case number to have statistically better acute patient survival was 4 cases/year, and 19 cases/year to have a statistically better rate of good outcomes.
For this analysis, good outcomes were defined as cases when patients left the hospital following their acute care and returned home with either self care or a home health care service, and also patients discharged to rehabilitation. “Bad” outcomes for this analysis were discharges to a skilled nursing facility or hospice, as well as patients who died during their acute hospitalization.
The analyses also showed no plateau to the volume effect for any of the four parameters examined: in-hospital mortality by center and by proceduralist, and the rates of good outcomes by center and by proceduralist. For each of these measures, as case volume increased above the minimum number needed to produce statistically better outcomes, the rate of good outcomes continued to steadily rise and acute mortality continued to steadily fall.
The study run by Dr. Stein and associates used data collected by the Center for Medicare & Medicaid Services on 13,311 Medicare patients who underwent endovascular thrombectomy for acute ischemic stroke at any of 641 U.S. hospitals and received treatment from any of 2,754 thrombectomy proceduralists. Outcomes rated as good occurred in 56% of the patients. The statistical adjustments that the researchers applied to calculate the incremental effect of increasing case volume took into account the variables of patient age, sex, and comorbidities measured by the Charlson Comorbidity Index.
The analysis also showed that, during this 2-year period, the average number of endovascular thrombectomy cases among Medicare patients was just under 21 cases per center, with a range of 1-160 cases; for individual proceduralists, the average was just under 5 cases, with a range of 1-82 cases.
The 19 case/year volume minimum that the analysis identified for an individual proceduralist to have a statistically significant higher rate of good outcomes, compared with lower-volume proceduralists, came close to the 15 cases/year minimum set by the Joint Commission in 2019 for individual operators at centers seeking accreditation from the Joint Commission as either a Thrombectomy-Capable Stroke Center or a Comprehensive Stroke Center. The CMS has not yet set thrombectomy case-load requirements for centers or operators to qualify for Medicare reimbursements, although CMS has set such standards for other endovascular procedures, such as transcatheter aortic valve replacement. When setting such standards, CMS has cited its need to balance the better outcomes produced by higher-volume centers against a societal interest in facilitating access to vital medical services, a balance that Dr. Stein also highlighted in her talk.
“We want to optimize access as well as outcomes for every patient,” she said. “These data support certification volume standards,” but they are “in no way an argument for limiting access based on volume.”
Dr. Stein had no disclosures.
SOURCE: Stein LK et al. ISC 2020, Abstract LB11.
REPORTING FROM ISC 2020
Carotid endarterectomy surpasses stenting in elderly, asymptomatic patients
LOS ANGELES – Carotid artery stenting in older, asymptomatic patients with severe carotid artery stenosis is, in general, as bad an idea as it has already proven to be in symptomatic patients, with a multifold increase in adverse short- and mid-term outcomes, compared with similar older, asymptomatic patients who underwent endarterectomy, according to a combined-study analysis with more than 2,500 patients.
The risk for poor outcomes in patients with severe but asymptomatic carotid artery disease who underwent carotid artery stenting (CAS), compared with patients who instead underwent carotid endarterectomy (CEA) “abruptly increased around age 75,” in an analysis that combined data from the two major, published, randomized trials that compared these two interventions in this patient population, Jenifer H. Voeks, PhD said at the International Stroke Conference sponsored by the American Heart Association.
These results “largely mirror” the findings from a similar combined analysis of data from four major, randomized trials that compared CEA and CAS in patients with symptomatic carotid disease, she noted (Lancet. 2016 Mar 26;387[10025]:1305-11). The new findings in an expanded population of asymptomatic patients derived from two separate studies showed that, in patients aged 70 years or less, “CAS appears to be a reasonable alternative to CEA, but above age 70, and certainly above age 75, age-related risk factors such as cerebrovascular anatomy and underlying cerebral pathology should be carefully considered before selecting patients for CAS,” said Dr. Voeks, a neurology researcher at the Medical University of South Carolina, Charleston. Many experts also believe that, for asymptomatic patients, intensive medical management may have returned as an alternative to either of these invasive approaches for treating severe carotid stenosis and has achieved a level of equipoise that led to the launch of CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial). CREST 2 is comparing CEA and CAS with medical management, and is scheduled to report results in 2021.
The data for this analysis in asymptomatic patients came from the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; N Engl J Med. 2010 Jul 1;363[1]:11-23), which included 1,181 asymptomatic patients (nearly half the total enrollment, with symptomatic patients making up the balance) and had no age ceiling, as well as all 1,453 patients from the ACT 1 trial, which enrolled exclusively asymptomatic patients and limited enrollment to patients aged 79 years or less (N Engl J Med. 2016 Mar 17;374[11]: 1011-20). Because the maximum age of patients in ACT 1 was 79 years, for this analysis Dr. Voeks and associates only included the 1,091 asymptomatic CREST patients who also were within the same age ceiling. The resulting cohort of 2,544 included 1,637 patients who underwent CAS and 907 who underwent CEA (because of a 3:1 randomization ratio in ACT 1), creating the largest data set to compare CAS and CEA by age in asymptomatic patients, Dr. Voeks noted. When subdivided by age, 30% of the cohort was younger that 65 years, 54% were 65-74, and 16% were 75-79.
The primary outcome the researchers used for their analysis was the combined incidence of periprocedural stroke, MI, or death, plus the incidence of ipsilateral stroke during 4 years of follow-up post procedure. Among patients who underwent CAS, this outcome occurred in roughly 9% of patients aged 75-79 years and in about 3% of those younger than 65 years, a hazard ratio of 2.9 that was statistically significant. In contrast, the incidence of the primary outcome among patients aged 65-74 years was just 30% higher, compared with patients aged less than 65 years, a difference that was not statistically significant.
Patients who underwent CEA showed no similar relationship between age and outcome. The incidence of the primary outcome among the CEA patients was roughly the same, about 3.5%, regardless of their age.
A second analysis that considered age as a continuous variable showed a sharply spiked increase in the risk for CAS patients, compared with CEA patients once they reached about age 73-75 years. Until about age 72, the rate of the primary outcome was nearly the same regardless of whether patients underwent CAS or CEA, but the risk for adverse outcomes rose “steeply” starting at about age 75 so that by age 79 the rate of the primary outcome approached 300% higher among the CAS patients compared with CEA patients, Dr. Voeks said.
She cautioned that the analysis included just 115 total primary-outcome events, which makes the incidence rate estimates somewhat imprecise, and that the data reflect outcomes in patients who were treated more than a decade ago, but these data remain the only reported results from large randomized trials that compared CAS and CEA in asymptomatic patients.
Dr. Voeks reported no disclosures.
SOURCE: Voeks JH al. Stroke. 2020 Feb 12;51[suppl 1], Abstract 70.
The role for carotid intervention in asymptomatic patients with severe carotid stenosis, usually defined as a stenosis that obstructs at least 70% of the carotid lumen, is controversial right now because intensive medical management has not been compared with invasive treatments, such as carotid endarterectomy and carotid stenting, for well over a decade. New drugs and new regimens have become treatment options for patients with advanced atherosclerotic carotid artery disease, and this has returned us to a state of equipoise for medical versus interventional management. That’s the premise behind CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial), which is comparing medical treatment against endarterectomy and against carotid stenting in a randomized study. The results may be available in 2021.
The new findings are very important for helping patients and their families make informed decisions. CAS is often perceived as the safer option for older patients because it is less traumatic and invasive than CEA. The data that Dr. Voeks reported show once again that this intuitive impression about CAS in the elderly is belied by the evidence. But the findings also require cautious interpretation because they came from a post hoc, subgroup analysis.
Mai N. Nguyen-Huynh, MD , is a vascular neurologist with Kaiser Permanente Northern California in Oakland. She had no relevant disclosures. She made these comments in an interview.
The role for carotid intervention in asymptomatic patients with severe carotid stenosis, usually defined as a stenosis that obstructs at least 70% of the carotid lumen, is controversial right now because intensive medical management has not been compared with invasive treatments, such as carotid endarterectomy and carotid stenting, for well over a decade. New drugs and new regimens have become treatment options for patients with advanced atherosclerotic carotid artery disease, and this has returned us to a state of equipoise for medical versus interventional management. That’s the premise behind CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial), which is comparing medical treatment against endarterectomy and against carotid stenting in a randomized study. The results may be available in 2021.
The new findings are very important for helping patients and their families make informed decisions. CAS is often perceived as the safer option for older patients because it is less traumatic and invasive than CEA. The data that Dr. Voeks reported show once again that this intuitive impression about CAS in the elderly is belied by the evidence. But the findings also require cautious interpretation because they came from a post hoc, subgroup analysis.
Mai N. Nguyen-Huynh, MD , is a vascular neurologist with Kaiser Permanente Northern California in Oakland. She had no relevant disclosures. She made these comments in an interview.
The role for carotid intervention in asymptomatic patients with severe carotid stenosis, usually defined as a stenosis that obstructs at least 70% of the carotid lumen, is controversial right now because intensive medical management has not been compared with invasive treatments, such as carotid endarterectomy and carotid stenting, for well over a decade. New drugs and new regimens have become treatment options for patients with advanced atherosclerotic carotid artery disease, and this has returned us to a state of equipoise for medical versus interventional management. That’s the premise behind CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial), which is comparing medical treatment against endarterectomy and against carotid stenting in a randomized study. The results may be available in 2021.
The new findings are very important for helping patients and their families make informed decisions. CAS is often perceived as the safer option for older patients because it is less traumatic and invasive than CEA. The data that Dr. Voeks reported show once again that this intuitive impression about CAS in the elderly is belied by the evidence. But the findings also require cautious interpretation because they came from a post hoc, subgroup analysis.
Mai N. Nguyen-Huynh, MD , is a vascular neurologist with Kaiser Permanente Northern California in Oakland. She had no relevant disclosures. She made these comments in an interview.
LOS ANGELES – Carotid artery stenting in older, asymptomatic patients with severe carotid artery stenosis is, in general, as bad an idea as it has already proven to be in symptomatic patients, with a multifold increase in adverse short- and mid-term outcomes, compared with similar older, asymptomatic patients who underwent endarterectomy, according to a combined-study analysis with more than 2,500 patients.
The risk for poor outcomes in patients with severe but asymptomatic carotid artery disease who underwent carotid artery stenting (CAS), compared with patients who instead underwent carotid endarterectomy (CEA) “abruptly increased around age 75,” in an analysis that combined data from the two major, published, randomized trials that compared these two interventions in this patient population, Jenifer H. Voeks, PhD said at the International Stroke Conference sponsored by the American Heart Association.
These results “largely mirror” the findings from a similar combined analysis of data from four major, randomized trials that compared CEA and CAS in patients with symptomatic carotid disease, she noted (Lancet. 2016 Mar 26;387[10025]:1305-11). The new findings in an expanded population of asymptomatic patients derived from two separate studies showed that, in patients aged 70 years or less, “CAS appears to be a reasonable alternative to CEA, but above age 70, and certainly above age 75, age-related risk factors such as cerebrovascular anatomy and underlying cerebral pathology should be carefully considered before selecting patients for CAS,” said Dr. Voeks, a neurology researcher at the Medical University of South Carolina, Charleston. Many experts also believe that, for asymptomatic patients, intensive medical management may have returned as an alternative to either of these invasive approaches for treating severe carotid stenosis and has achieved a level of equipoise that led to the launch of CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial). CREST 2 is comparing CEA and CAS with medical management, and is scheduled to report results in 2021.
The data for this analysis in asymptomatic patients came from the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; N Engl J Med. 2010 Jul 1;363[1]:11-23), which included 1,181 asymptomatic patients (nearly half the total enrollment, with symptomatic patients making up the balance) and had no age ceiling, as well as all 1,453 patients from the ACT 1 trial, which enrolled exclusively asymptomatic patients and limited enrollment to patients aged 79 years or less (N Engl J Med. 2016 Mar 17;374[11]: 1011-20). Because the maximum age of patients in ACT 1 was 79 years, for this analysis Dr. Voeks and associates only included the 1,091 asymptomatic CREST patients who also were within the same age ceiling. The resulting cohort of 2,544 included 1,637 patients who underwent CAS and 907 who underwent CEA (because of a 3:1 randomization ratio in ACT 1), creating the largest data set to compare CAS and CEA by age in asymptomatic patients, Dr. Voeks noted. When subdivided by age, 30% of the cohort was younger that 65 years, 54% were 65-74, and 16% were 75-79.
The primary outcome the researchers used for their analysis was the combined incidence of periprocedural stroke, MI, or death, plus the incidence of ipsilateral stroke during 4 years of follow-up post procedure. Among patients who underwent CAS, this outcome occurred in roughly 9% of patients aged 75-79 years and in about 3% of those younger than 65 years, a hazard ratio of 2.9 that was statistically significant. In contrast, the incidence of the primary outcome among patients aged 65-74 years was just 30% higher, compared with patients aged less than 65 years, a difference that was not statistically significant.
Patients who underwent CEA showed no similar relationship between age and outcome. The incidence of the primary outcome among the CEA patients was roughly the same, about 3.5%, regardless of their age.
A second analysis that considered age as a continuous variable showed a sharply spiked increase in the risk for CAS patients, compared with CEA patients once they reached about age 73-75 years. Until about age 72, the rate of the primary outcome was nearly the same regardless of whether patients underwent CAS or CEA, but the risk for adverse outcomes rose “steeply” starting at about age 75 so that by age 79 the rate of the primary outcome approached 300% higher among the CAS patients compared with CEA patients, Dr. Voeks said.
She cautioned that the analysis included just 115 total primary-outcome events, which makes the incidence rate estimates somewhat imprecise, and that the data reflect outcomes in patients who were treated more than a decade ago, but these data remain the only reported results from large randomized trials that compared CAS and CEA in asymptomatic patients.
Dr. Voeks reported no disclosures.
SOURCE: Voeks JH al. Stroke. 2020 Feb 12;51[suppl 1], Abstract 70.
LOS ANGELES – Carotid artery stenting in older, asymptomatic patients with severe carotid artery stenosis is, in general, as bad an idea as it has already proven to be in symptomatic patients, with a multifold increase in adverse short- and mid-term outcomes, compared with similar older, asymptomatic patients who underwent endarterectomy, according to a combined-study analysis with more than 2,500 patients.
The risk for poor outcomes in patients with severe but asymptomatic carotid artery disease who underwent carotid artery stenting (CAS), compared with patients who instead underwent carotid endarterectomy (CEA) “abruptly increased around age 75,” in an analysis that combined data from the two major, published, randomized trials that compared these two interventions in this patient population, Jenifer H. Voeks, PhD said at the International Stroke Conference sponsored by the American Heart Association.
These results “largely mirror” the findings from a similar combined analysis of data from four major, randomized trials that compared CEA and CAS in patients with symptomatic carotid disease, she noted (Lancet. 2016 Mar 26;387[10025]:1305-11). The new findings in an expanded population of asymptomatic patients derived from two separate studies showed that, in patients aged 70 years or less, “CAS appears to be a reasonable alternative to CEA, but above age 70, and certainly above age 75, age-related risk factors such as cerebrovascular anatomy and underlying cerebral pathology should be carefully considered before selecting patients for CAS,” said Dr. Voeks, a neurology researcher at the Medical University of South Carolina, Charleston. Many experts also believe that, for asymptomatic patients, intensive medical management may have returned as an alternative to either of these invasive approaches for treating severe carotid stenosis and has achieved a level of equipoise that led to the launch of CREST 2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial). CREST 2 is comparing CEA and CAS with medical management, and is scheduled to report results in 2021.
The data for this analysis in asymptomatic patients came from the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; N Engl J Med. 2010 Jul 1;363[1]:11-23), which included 1,181 asymptomatic patients (nearly half the total enrollment, with symptomatic patients making up the balance) and had no age ceiling, as well as all 1,453 patients from the ACT 1 trial, which enrolled exclusively asymptomatic patients and limited enrollment to patients aged 79 years or less (N Engl J Med. 2016 Mar 17;374[11]: 1011-20). Because the maximum age of patients in ACT 1 was 79 years, for this analysis Dr. Voeks and associates only included the 1,091 asymptomatic CREST patients who also were within the same age ceiling. The resulting cohort of 2,544 included 1,637 patients who underwent CAS and 907 who underwent CEA (because of a 3:1 randomization ratio in ACT 1), creating the largest data set to compare CAS and CEA by age in asymptomatic patients, Dr. Voeks noted. When subdivided by age, 30% of the cohort was younger that 65 years, 54% were 65-74, and 16% were 75-79.
The primary outcome the researchers used for their analysis was the combined incidence of periprocedural stroke, MI, or death, plus the incidence of ipsilateral stroke during 4 years of follow-up post procedure. Among patients who underwent CAS, this outcome occurred in roughly 9% of patients aged 75-79 years and in about 3% of those younger than 65 years, a hazard ratio of 2.9 that was statistically significant. In contrast, the incidence of the primary outcome among patients aged 65-74 years was just 30% higher, compared with patients aged less than 65 years, a difference that was not statistically significant.
Patients who underwent CEA showed no similar relationship between age and outcome. The incidence of the primary outcome among the CEA patients was roughly the same, about 3.5%, regardless of their age.
A second analysis that considered age as a continuous variable showed a sharply spiked increase in the risk for CAS patients, compared with CEA patients once they reached about age 73-75 years. Until about age 72, the rate of the primary outcome was nearly the same regardless of whether patients underwent CAS or CEA, but the risk for adverse outcomes rose “steeply” starting at about age 75 so that by age 79 the rate of the primary outcome approached 300% higher among the CAS patients compared with CEA patients, Dr. Voeks said.
She cautioned that the analysis included just 115 total primary-outcome events, which makes the incidence rate estimates somewhat imprecise, and that the data reflect outcomes in patients who were treated more than a decade ago, but these data remain the only reported results from large randomized trials that compared CAS and CEA in asymptomatic patients.
Dr. Voeks reported no disclosures.
SOURCE: Voeks JH al. Stroke. 2020 Feb 12;51[suppl 1], Abstract 70.
REPORTING FROM ISC 2020
Pulsed field catheter ablation shows huge clinical promise for AFib
NATIONAL HARBOR, MD. – Cardiac electrophysiologists have reported using pulsed field ablation, a new power source for catheter ablation of atrial fibrillation, on fewer than 150 patients worldwide in initial clinical studies, but its performance so far and the promise it carries for substantially improving the safety and efficacy of catheter ablation has convinced many experts that it represents the future for this intervention.
“I’m very excited about PFA [pulsed field ablation]. It may make everything else obsolete,” Andrea Natale, MD, said at the annual International AF Symposium. “We need to see more efficacy data, but just for safety alone there is no reason to use anything else,” commented Dr. Natale, executive medical director of the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin,Tex.
“The main issue is safety, and if PFA lives up to its promise, then [using it preferentially] is not a difficult decision,” commented Francis E. Marchlinski, MD, professor of medicine and director of electrophysiology at the University of Pennsylvania.
“The only question is whether it has good long-term efficacy” because so far no patients have been followed for longer than about a year after PFA treatment, noted Moussa Mansour, MD, director of the cardiac electrophysiology laboratory at Massachusetts General Hospital in Boston. “If that piece turns out to be true, then I think it will be a winner.”
Vivek Y. Reddy, MD, one of the few investigators to have already collaborated on clinical studies that used PFA to catheter ablate both in patients with paroxysmal and, more recently, persistent atrial fibrillation (AFib), put it this way: “I’m 99% sure” PFA will be the energy of choice in the near future for AFib catheter ablation. The 1% of uncertainty “is only because of what might be unknown, something we’re not expecting,” said Dr. Reddy, professor of medicine and director of the cardiac arrhythmia service at Mount Sinai Medical Center in New York.
He and his associates at a center in Prague and at a second site in Bordeaux, France, reported their collective experience in 2019 regarding use of PFA on 81 patients with symptomatic, paroxysmal AFib who had not responded to at least one antiarrhythmic drug (J Am Coll Cardiol. 2019 Jul;74[3]:315-26). During a session on PFA at the symposium, Pierre Jaïs, MD, a cardiac electrophysiologist and professor of cardiology at the University of Bordeaux, updated this experience to now include 113 patients treated by the end of 2019 at the same two centers plus now an added third site, an experience accumulated by a total of five operators. Fifty-one patients have now been followed for at least a year, with no “unexpected” safety events, said Dr. Jaïs, The most recent 88 patients underwent PFA without general anesthesia. The ablation technique has undergone several refinements during this experience, and with use of the most recent, biphasic protocol that’s so far treated 26 patients, 24 (92%) of the treated patients had no reconnected AFib circuits in their atrial tissue when they underwent remapping 3 months after their procedure.
Magnetic resonance imaging of the left atria of these patients after pulmonary vein isolation with PFA showed a uniquely homogeneous and continuous lesion that functionally isolated each vein from surrounding atrial tissue and denoted a more uniform and complete ablation, Dr. Jaïs noted. “I have never seen [an ablation] as homogeneous.” The Magnetic resonance pictures also showed that the esophagus in each treated patient remained completely undamaged. “Esophageal sparing is systematically observed,” along with phrenic nerve sparing that’s in notable contrast with what’s seen with conventional energy sources, he said. The images also indicated that edema was substantially reduced compared with both radiofrequency and cryoablation, while mechanical function of treated left atria has consistently been “well preserved.”
“For the first time, we can use extra power to ensure durable lesions without compromising safety,” Dr. Jaïs concluded. PFA appears to put AFib ablation “on the verge of a totally new era.”
The less extensive and briefer experience in patients with persistent AFib has been completely consistent. This included 25 patients who had not responded to at least one antiarrhythmic drug treated by either of two operators, one in Prague and the other in Split, Croatia. All 25 patients who underwent pulmonary vein isolation had the procedure successfully completed as assessed with acute mapping of arrhythmia circuits after ablation, and the 24 of these patients who also underwent posterior wall ablation with the PFA device all had a successful acute result according to mapping, Dr. Reddy reported. No patient had an adverse event. PFA treatments were relatively fast, with an average procedure time in this series of 132 minutes. Repeat mapping 3 months after treatment is still pending.
At the heart of PFA’s safety is its “myocardial selectivity” which has so far kept PFA from causing any esophageal or phrenic nerve injuries, two potential complications of conventional AFib catheter ablation with use of either radiofrequency or cryo energy. Dr. Reddy was quick to highlight that there is no absolute selectivity for myocardium. “If you create a big enough field, it will electroporate everything, but the margin [between safety and damage] seems wide enough to take advantage” of focally damaging myocardial tissue in the left atrium to disrupt arrhythmia circuits while sparing adjacent tissue. Irreversible electroporation is the means by which PFA destroys targets cells while leaving other tissue unscathed, and a precisely adjusted PFA signal can focus its lethal effect exclusively on myocardial cells, a feature of PFA that Dr. Reddy called “lucky.”
The pulsed field ablation studies have been sponsored by Farapulse, the company developing this device, which in May 2019 received breakthrough designation for priority review from the Food and Drug Administration.
Dr. Reddy and Dr. Jaïs are both consultants to and shareholders in Farapulse. Dr. Natale has received honoraria from or has been a consultant to Biotronik, Janssen, Medtronic, and St. Jude. Dr. Marchlinski has been a consultant to or has received honoraria from Abbott EP/St. Jude, Biotronik, and Medtronic. Dr. Mansour has been a consultant for Abbott and Medtronic, has an equity interest or stock options in NewPace and EPD Solutions, and has received research grants from Abbott, Boehringer Ingelheim, Pfizer, and Sentre Heart. In addition, all sources have received consulting fees, honoraria, and/or research grants from Biosense Webster and Boston Scientific.
NATIONAL HARBOR, MD. – Cardiac electrophysiologists have reported using pulsed field ablation, a new power source for catheter ablation of atrial fibrillation, on fewer than 150 patients worldwide in initial clinical studies, but its performance so far and the promise it carries for substantially improving the safety and efficacy of catheter ablation has convinced many experts that it represents the future for this intervention.
“I’m very excited about PFA [pulsed field ablation]. It may make everything else obsolete,” Andrea Natale, MD, said at the annual International AF Symposium. “We need to see more efficacy data, but just for safety alone there is no reason to use anything else,” commented Dr. Natale, executive medical director of the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin,Tex.
“The main issue is safety, and if PFA lives up to its promise, then [using it preferentially] is not a difficult decision,” commented Francis E. Marchlinski, MD, professor of medicine and director of electrophysiology at the University of Pennsylvania.
“The only question is whether it has good long-term efficacy” because so far no patients have been followed for longer than about a year after PFA treatment, noted Moussa Mansour, MD, director of the cardiac electrophysiology laboratory at Massachusetts General Hospital in Boston. “If that piece turns out to be true, then I think it will be a winner.”
Vivek Y. Reddy, MD, one of the few investigators to have already collaborated on clinical studies that used PFA to catheter ablate both in patients with paroxysmal and, more recently, persistent atrial fibrillation (AFib), put it this way: “I’m 99% sure” PFA will be the energy of choice in the near future for AFib catheter ablation. The 1% of uncertainty “is only because of what might be unknown, something we’re not expecting,” said Dr. Reddy, professor of medicine and director of the cardiac arrhythmia service at Mount Sinai Medical Center in New York.
He and his associates at a center in Prague and at a second site in Bordeaux, France, reported their collective experience in 2019 regarding use of PFA on 81 patients with symptomatic, paroxysmal AFib who had not responded to at least one antiarrhythmic drug (J Am Coll Cardiol. 2019 Jul;74[3]:315-26). During a session on PFA at the symposium, Pierre Jaïs, MD, a cardiac electrophysiologist and professor of cardiology at the University of Bordeaux, updated this experience to now include 113 patients treated by the end of 2019 at the same two centers plus now an added third site, an experience accumulated by a total of five operators. Fifty-one patients have now been followed for at least a year, with no “unexpected” safety events, said Dr. Jaïs, The most recent 88 patients underwent PFA without general anesthesia. The ablation technique has undergone several refinements during this experience, and with use of the most recent, biphasic protocol that’s so far treated 26 patients, 24 (92%) of the treated patients had no reconnected AFib circuits in their atrial tissue when they underwent remapping 3 months after their procedure.
Magnetic resonance imaging of the left atria of these patients after pulmonary vein isolation with PFA showed a uniquely homogeneous and continuous lesion that functionally isolated each vein from surrounding atrial tissue and denoted a more uniform and complete ablation, Dr. Jaïs noted. “I have never seen [an ablation] as homogeneous.” The Magnetic resonance pictures also showed that the esophagus in each treated patient remained completely undamaged. “Esophageal sparing is systematically observed,” along with phrenic nerve sparing that’s in notable contrast with what’s seen with conventional energy sources, he said. The images also indicated that edema was substantially reduced compared with both radiofrequency and cryoablation, while mechanical function of treated left atria has consistently been “well preserved.”
“For the first time, we can use extra power to ensure durable lesions without compromising safety,” Dr. Jaïs concluded. PFA appears to put AFib ablation “on the verge of a totally new era.”
The less extensive and briefer experience in patients with persistent AFib has been completely consistent. This included 25 patients who had not responded to at least one antiarrhythmic drug treated by either of two operators, one in Prague and the other in Split, Croatia. All 25 patients who underwent pulmonary vein isolation had the procedure successfully completed as assessed with acute mapping of arrhythmia circuits after ablation, and the 24 of these patients who also underwent posterior wall ablation with the PFA device all had a successful acute result according to mapping, Dr. Reddy reported. No patient had an adverse event. PFA treatments were relatively fast, with an average procedure time in this series of 132 minutes. Repeat mapping 3 months after treatment is still pending.
At the heart of PFA’s safety is its “myocardial selectivity” which has so far kept PFA from causing any esophageal or phrenic nerve injuries, two potential complications of conventional AFib catheter ablation with use of either radiofrequency or cryo energy. Dr. Reddy was quick to highlight that there is no absolute selectivity for myocardium. “If you create a big enough field, it will electroporate everything, but the margin [between safety and damage] seems wide enough to take advantage” of focally damaging myocardial tissue in the left atrium to disrupt arrhythmia circuits while sparing adjacent tissue. Irreversible electroporation is the means by which PFA destroys targets cells while leaving other tissue unscathed, and a precisely adjusted PFA signal can focus its lethal effect exclusively on myocardial cells, a feature of PFA that Dr. Reddy called “lucky.”
The pulsed field ablation studies have been sponsored by Farapulse, the company developing this device, which in May 2019 received breakthrough designation for priority review from the Food and Drug Administration.
Dr. Reddy and Dr. Jaïs are both consultants to and shareholders in Farapulse. Dr. Natale has received honoraria from or has been a consultant to Biotronik, Janssen, Medtronic, and St. Jude. Dr. Marchlinski has been a consultant to or has received honoraria from Abbott EP/St. Jude, Biotronik, and Medtronic. Dr. Mansour has been a consultant for Abbott and Medtronic, has an equity interest or stock options in NewPace and EPD Solutions, and has received research grants from Abbott, Boehringer Ingelheim, Pfizer, and Sentre Heart. In addition, all sources have received consulting fees, honoraria, and/or research grants from Biosense Webster and Boston Scientific.
NATIONAL HARBOR, MD. – Cardiac electrophysiologists have reported using pulsed field ablation, a new power source for catheter ablation of atrial fibrillation, on fewer than 150 patients worldwide in initial clinical studies, but its performance so far and the promise it carries for substantially improving the safety and efficacy of catheter ablation has convinced many experts that it represents the future for this intervention.
“I’m very excited about PFA [pulsed field ablation]. It may make everything else obsolete,” Andrea Natale, MD, said at the annual International AF Symposium. “We need to see more efficacy data, but just for safety alone there is no reason to use anything else,” commented Dr. Natale, executive medical director of the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin,Tex.
“The main issue is safety, and if PFA lives up to its promise, then [using it preferentially] is not a difficult decision,” commented Francis E. Marchlinski, MD, professor of medicine and director of electrophysiology at the University of Pennsylvania.
“The only question is whether it has good long-term efficacy” because so far no patients have been followed for longer than about a year after PFA treatment, noted Moussa Mansour, MD, director of the cardiac electrophysiology laboratory at Massachusetts General Hospital in Boston. “If that piece turns out to be true, then I think it will be a winner.”
Vivek Y. Reddy, MD, one of the few investigators to have already collaborated on clinical studies that used PFA to catheter ablate both in patients with paroxysmal and, more recently, persistent atrial fibrillation (AFib), put it this way: “I’m 99% sure” PFA will be the energy of choice in the near future for AFib catheter ablation. The 1% of uncertainty “is only because of what might be unknown, something we’re not expecting,” said Dr. Reddy, professor of medicine and director of the cardiac arrhythmia service at Mount Sinai Medical Center in New York.
He and his associates at a center in Prague and at a second site in Bordeaux, France, reported their collective experience in 2019 regarding use of PFA on 81 patients with symptomatic, paroxysmal AFib who had not responded to at least one antiarrhythmic drug (J Am Coll Cardiol. 2019 Jul;74[3]:315-26). During a session on PFA at the symposium, Pierre Jaïs, MD, a cardiac electrophysiologist and professor of cardiology at the University of Bordeaux, updated this experience to now include 113 patients treated by the end of 2019 at the same two centers plus now an added third site, an experience accumulated by a total of five operators. Fifty-one patients have now been followed for at least a year, with no “unexpected” safety events, said Dr. Jaïs, The most recent 88 patients underwent PFA without general anesthesia. The ablation technique has undergone several refinements during this experience, and with use of the most recent, biphasic protocol that’s so far treated 26 patients, 24 (92%) of the treated patients had no reconnected AFib circuits in their atrial tissue when they underwent remapping 3 months after their procedure.
Magnetic resonance imaging of the left atria of these patients after pulmonary vein isolation with PFA showed a uniquely homogeneous and continuous lesion that functionally isolated each vein from surrounding atrial tissue and denoted a more uniform and complete ablation, Dr. Jaïs noted. “I have never seen [an ablation] as homogeneous.” The Magnetic resonance pictures also showed that the esophagus in each treated patient remained completely undamaged. “Esophageal sparing is systematically observed,” along with phrenic nerve sparing that’s in notable contrast with what’s seen with conventional energy sources, he said. The images also indicated that edema was substantially reduced compared with both radiofrequency and cryoablation, while mechanical function of treated left atria has consistently been “well preserved.”
“For the first time, we can use extra power to ensure durable lesions without compromising safety,” Dr. Jaïs concluded. PFA appears to put AFib ablation “on the verge of a totally new era.”
The less extensive and briefer experience in patients with persistent AFib has been completely consistent. This included 25 patients who had not responded to at least one antiarrhythmic drug treated by either of two operators, one in Prague and the other in Split, Croatia. All 25 patients who underwent pulmonary vein isolation had the procedure successfully completed as assessed with acute mapping of arrhythmia circuits after ablation, and the 24 of these patients who also underwent posterior wall ablation with the PFA device all had a successful acute result according to mapping, Dr. Reddy reported. No patient had an adverse event. PFA treatments were relatively fast, with an average procedure time in this series of 132 minutes. Repeat mapping 3 months after treatment is still pending.
At the heart of PFA’s safety is its “myocardial selectivity” which has so far kept PFA from causing any esophageal or phrenic nerve injuries, two potential complications of conventional AFib catheter ablation with use of either radiofrequency or cryo energy. Dr. Reddy was quick to highlight that there is no absolute selectivity for myocardium. “If you create a big enough field, it will electroporate everything, but the margin [between safety and damage] seems wide enough to take advantage” of focally damaging myocardial tissue in the left atrium to disrupt arrhythmia circuits while sparing adjacent tissue. Irreversible electroporation is the means by which PFA destroys targets cells while leaving other tissue unscathed, and a precisely adjusted PFA signal can focus its lethal effect exclusively on myocardial cells, a feature of PFA that Dr. Reddy called “lucky.”
The pulsed field ablation studies have been sponsored by Farapulse, the company developing this device, which in May 2019 received breakthrough designation for priority review from the Food and Drug Administration.
Dr. Reddy and Dr. Jaïs are both consultants to and shareholders in Farapulse. Dr. Natale has received honoraria from or has been a consultant to Biotronik, Janssen, Medtronic, and St. Jude. Dr. Marchlinski has been a consultant to or has received honoraria from Abbott EP/St. Jude, Biotronik, and Medtronic. Dr. Mansour has been a consultant for Abbott and Medtronic, has an equity interest or stock options in NewPace and EPD Solutions, and has received research grants from Abbott, Boehringer Ingelheim, Pfizer, and Sentre Heart. In addition, all sources have received consulting fees, honoraria, and/or research grants from Biosense Webster and Boston Scientific.
EXPERT ANALYSIS FROM THE AF SYMPOSIUM 2020
‘A glimmer of hope’ for stroke/mortality benefit with AFib catheter ablation
SNOWMASS, COLO. – stroke, major bleeding, or cardiac arrest, compared with rhythm and/or rate control drugs in a propensity score–weighted, retrospective, observational study.
Findings of the investigation, which included more than 183,000 real-world patients in routine clinical practice, were reported by Peter S. Noseworthy, MD, during the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
The results breathe new life into the controversy created by the previously reported CABANA trial (Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation), a 10-country study in which 2,204 patients with atrial fibrillation (AFib) were randomized to catheter ablation or antiarrhythmic and/or rhythm control medications and followed for a mean of about 4 years. CABANA yielded a negative result (JAMA. 2019 Apr 2;321[13]:1261-74), with the prespecified intent-to-treat analysis indicating no significant between-group difference in the primary composite endpoint – the very same one that was positive in the large observational study.
However, CABANA was marred by major problems arising from protocol deviations: Nearly 28% of patients assigned to medical therapy crossed over to catheter ablation, typically because their antiarrhythmic drugs failed, and 10% of patients randomized to catheter ablation never got it. This muddies the waters when trying to identify a true stroke/mortality benefit for catheter ablation, if indeed any such benefit was actually present.
Here’s where the controversy arose: While CABANA must be called a negative trial based upon the disappointing results of the intent-to-treat analysis, a prespecified post hoc analysis of patients as actually treated showed a statistically significant 27% relative risk reduction for the primary composite endpoint in the catheter ablation group. That’s strikingly similar to the 30% relative risk reduction for catheter ablation seen in the huge observational study, where the CABANA-type primary outcome occurred in 22.5% of the medically managed patients and 16.8% of those who underwent catheter ablation, noted Dr. Noseworthy, professor of medicine and director of heart rhythm and physiology at the Mayo Clinic in Rochester, Minn.
He ought to know: He was both an investigator in CABANA and first author of the published observational study (Eur Heart J. 2019 Apr 21;40[16]:1257-64).
In the observational study, Dr. Noseworthy and coinvestigators utilized a huge U.S. administrative health claims database in order to identify a nationally representative group of 183,760 AFib patients, 12,032 of whom were treated with catheter ablation and the rest with antiarrhythmic and/or rhythm control drugs during the same years the CABANA trial was enrolling patients. The two groups were balanced using propensity score weighting to adjust for baseline differences in 90 variables.
The investigators sought to learn if the CABANA study population was representative of real-world AFib patients, and whether the observational experience could help resolve the CABANA controversy. It turned out that most AFib patients seen in daily clinical practice were CABANA like; that is, 74% of them would have been eligible for the clinical trial because they were symptomatic, over age 65, or younger than 65 with at least one CHADS2 stroke risk factor. About 22% of the large real-world sample would have been excluded from CABANA because they’d failed on amiodarone and other antiarrhythmic agents or had previously undergone ablation. About 4% of patients failed to meet the CABANA inclusion criteria.
The risk reduction for the composite endpoint associated with catheter ablation in the large retrospective study was greatest in the CABANA-like patients, at 30%. It was less robust but still statistically significant at 15% in patients who met at least one of the exclusion criteria for the trial.
The sheer size of this study provides greater statistical power than in CABANA. Of course, a nonrandomized, propensity score–based comparison such as this is always susceptible to confounding, even after adjustment for 90 variables. But the observational study does offer “a glimmer of hope” that catheter ablation, done in the right patients, might confer a stroke risk reduction and mortality benefit, he said.
The 33% relative risk reduction in the small group of real-world patients who failed to meet the CABANA inclusion criteria, while numerically impressive, wasn’t close to statistical significance, probably because event rates in that population were so low.
“Even if you could reduce stroke risk with ablation in that low-risk group, it would be a very inefficient way to reduce the population burden of stroke,” Dr. Noseworthy observed.
Putting together the results of CABANA and the large observational study to sum up his view of where catheter ablation for AF[ib] stands today, Dr. Noseworthy commented, “Ablation is reasonable for symptom control in many patients, basically anyone who is either breaking through on drugs or doesn’t want to take the drugs and is highly symptomatic. And there may be a small stroke and/or mortality benefit for people who are in the sweet spot – and those are people who look a lot like the patients enrolled in CABANA.”
Patients who met the exclusion criteria for CABANA are too advanced in their AFib to be likely to derive a stroke or mortality benefit from catheter ablation. “It’s very hard to move the needle in these patients with either a drug or catheter ablation approach. I wouldn’t try to reduce the risk of stroke here with an expensive and invasive procedure,” the electrophysiologist concluded.
He reported having no financial conflicts regarding his presentation.
SNOWMASS, COLO. – stroke, major bleeding, or cardiac arrest, compared with rhythm and/or rate control drugs in a propensity score–weighted, retrospective, observational study.
Findings of the investigation, which included more than 183,000 real-world patients in routine clinical practice, were reported by Peter S. Noseworthy, MD, during the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
The results breathe new life into the controversy created by the previously reported CABANA trial (Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation), a 10-country study in which 2,204 patients with atrial fibrillation (AFib) were randomized to catheter ablation or antiarrhythmic and/or rhythm control medications and followed for a mean of about 4 years. CABANA yielded a negative result (JAMA. 2019 Apr 2;321[13]:1261-74), with the prespecified intent-to-treat analysis indicating no significant between-group difference in the primary composite endpoint – the very same one that was positive in the large observational study.
However, CABANA was marred by major problems arising from protocol deviations: Nearly 28% of patients assigned to medical therapy crossed over to catheter ablation, typically because their antiarrhythmic drugs failed, and 10% of patients randomized to catheter ablation never got it. This muddies the waters when trying to identify a true stroke/mortality benefit for catheter ablation, if indeed any such benefit was actually present.
Here’s where the controversy arose: While CABANA must be called a negative trial based upon the disappointing results of the intent-to-treat analysis, a prespecified post hoc analysis of patients as actually treated showed a statistically significant 27% relative risk reduction for the primary composite endpoint in the catheter ablation group. That’s strikingly similar to the 30% relative risk reduction for catheter ablation seen in the huge observational study, where the CABANA-type primary outcome occurred in 22.5% of the medically managed patients and 16.8% of those who underwent catheter ablation, noted Dr. Noseworthy, professor of medicine and director of heart rhythm and physiology at the Mayo Clinic in Rochester, Minn.
He ought to know: He was both an investigator in CABANA and first author of the published observational study (Eur Heart J. 2019 Apr 21;40[16]:1257-64).
In the observational study, Dr. Noseworthy and coinvestigators utilized a huge U.S. administrative health claims database in order to identify a nationally representative group of 183,760 AFib patients, 12,032 of whom were treated with catheter ablation and the rest with antiarrhythmic and/or rhythm control drugs during the same years the CABANA trial was enrolling patients. The two groups were balanced using propensity score weighting to adjust for baseline differences in 90 variables.
The investigators sought to learn if the CABANA study population was representative of real-world AFib patients, and whether the observational experience could help resolve the CABANA controversy. It turned out that most AFib patients seen in daily clinical practice were CABANA like; that is, 74% of them would have been eligible for the clinical trial because they were symptomatic, over age 65, or younger than 65 with at least one CHADS2 stroke risk factor. About 22% of the large real-world sample would have been excluded from CABANA because they’d failed on amiodarone and other antiarrhythmic agents or had previously undergone ablation. About 4% of patients failed to meet the CABANA inclusion criteria.
The risk reduction for the composite endpoint associated with catheter ablation in the large retrospective study was greatest in the CABANA-like patients, at 30%. It was less robust but still statistically significant at 15% in patients who met at least one of the exclusion criteria for the trial.
The sheer size of this study provides greater statistical power than in CABANA. Of course, a nonrandomized, propensity score–based comparison such as this is always susceptible to confounding, even after adjustment for 90 variables. But the observational study does offer “a glimmer of hope” that catheter ablation, done in the right patients, might confer a stroke risk reduction and mortality benefit, he said.
The 33% relative risk reduction in the small group of real-world patients who failed to meet the CABANA inclusion criteria, while numerically impressive, wasn’t close to statistical significance, probably because event rates in that population were so low.
“Even if you could reduce stroke risk with ablation in that low-risk group, it would be a very inefficient way to reduce the population burden of stroke,” Dr. Noseworthy observed.
Putting together the results of CABANA and the large observational study to sum up his view of where catheter ablation for AF[ib] stands today, Dr. Noseworthy commented, “Ablation is reasonable for symptom control in many patients, basically anyone who is either breaking through on drugs or doesn’t want to take the drugs and is highly symptomatic. And there may be a small stroke and/or mortality benefit for people who are in the sweet spot – and those are people who look a lot like the patients enrolled in CABANA.”
Patients who met the exclusion criteria for CABANA are too advanced in their AFib to be likely to derive a stroke or mortality benefit from catheter ablation. “It’s very hard to move the needle in these patients with either a drug or catheter ablation approach. I wouldn’t try to reduce the risk of stroke here with an expensive and invasive procedure,” the electrophysiologist concluded.
He reported having no financial conflicts regarding his presentation.
SNOWMASS, COLO. – stroke, major bleeding, or cardiac arrest, compared with rhythm and/or rate control drugs in a propensity score–weighted, retrospective, observational study.
Findings of the investigation, which included more than 183,000 real-world patients in routine clinical practice, were reported by Peter S. Noseworthy, MD, during the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
The results breathe new life into the controversy created by the previously reported CABANA trial (Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation), a 10-country study in which 2,204 patients with atrial fibrillation (AFib) were randomized to catheter ablation or antiarrhythmic and/or rhythm control medications and followed for a mean of about 4 years. CABANA yielded a negative result (JAMA. 2019 Apr 2;321[13]:1261-74), with the prespecified intent-to-treat analysis indicating no significant between-group difference in the primary composite endpoint – the very same one that was positive in the large observational study.
However, CABANA was marred by major problems arising from protocol deviations: Nearly 28% of patients assigned to medical therapy crossed over to catheter ablation, typically because their antiarrhythmic drugs failed, and 10% of patients randomized to catheter ablation never got it. This muddies the waters when trying to identify a true stroke/mortality benefit for catheter ablation, if indeed any such benefit was actually present.
Here’s where the controversy arose: While CABANA must be called a negative trial based upon the disappointing results of the intent-to-treat analysis, a prespecified post hoc analysis of patients as actually treated showed a statistically significant 27% relative risk reduction for the primary composite endpoint in the catheter ablation group. That’s strikingly similar to the 30% relative risk reduction for catheter ablation seen in the huge observational study, where the CABANA-type primary outcome occurred in 22.5% of the medically managed patients and 16.8% of those who underwent catheter ablation, noted Dr. Noseworthy, professor of medicine and director of heart rhythm and physiology at the Mayo Clinic in Rochester, Minn.
He ought to know: He was both an investigator in CABANA and first author of the published observational study (Eur Heart J. 2019 Apr 21;40[16]:1257-64).
In the observational study, Dr. Noseworthy and coinvestigators utilized a huge U.S. administrative health claims database in order to identify a nationally representative group of 183,760 AFib patients, 12,032 of whom were treated with catheter ablation and the rest with antiarrhythmic and/or rhythm control drugs during the same years the CABANA trial was enrolling patients. The two groups were balanced using propensity score weighting to adjust for baseline differences in 90 variables.
The investigators sought to learn if the CABANA study population was representative of real-world AFib patients, and whether the observational experience could help resolve the CABANA controversy. It turned out that most AFib patients seen in daily clinical practice were CABANA like; that is, 74% of them would have been eligible for the clinical trial because they were symptomatic, over age 65, or younger than 65 with at least one CHADS2 stroke risk factor. About 22% of the large real-world sample would have been excluded from CABANA because they’d failed on amiodarone and other antiarrhythmic agents or had previously undergone ablation. About 4% of patients failed to meet the CABANA inclusion criteria.
The risk reduction for the composite endpoint associated with catheter ablation in the large retrospective study was greatest in the CABANA-like patients, at 30%. It was less robust but still statistically significant at 15% in patients who met at least one of the exclusion criteria for the trial.
The sheer size of this study provides greater statistical power than in CABANA. Of course, a nonrandomized, propensity score–based comparison such as this is always susceptible to confounding, even after adjustment for 90 variables. But the observational study does offer “a glimmer of hope” that catheter ablation, done in the right patients, might confer a stroke risk reduction and mortality benefit, he said.
The 33% relative risk reduction in the small group of real-world patients who failed to meet the CABANA inclusion criteria, while numerically impressive, wasn’t close to statistical significance, probably because event rates in that population were so low.
“Even if you could reduce stroke risk with ablation in that low-risk group, it would be a very inefficient way to reduce the population burden of stroke,” Dr. Noseworthy observed.
Putting together the results of CABANA and the large observational study to sum up his view of where catheter ablation for AF[ib] stands today, Dr. Noseworthy commented, “Ablation is reasonable for symptom control in many patients, basically anyone who is either breaking through on drugs or doesn’t want to take the drugs and is highly symptomatic. And there may be a small stroke and/or mortality benefit for people who are in the sweet spot – and those are people who look a lot like the patients enrolled in CABANA.”
Patients who met the exclusion criteria for CABANA are too advanced in their AFib to be likely to derive a stroke or mortality benefit from catheter ablation. “It’s very hard to move the needle in these patients with either a drug or catheter ablation approach. I wouldn’t try to reduce the risk of stroke here with an expensive and invasive procedure,” the electrophysiologist concluded.
He reported having no financial conflicts regarding his presentation.
REPORTING FROM ACC SNOWMASS 2020
Thrombectomy access lags for U.S. stroke patients
In 2017, roughly 3 years after evidence from several studies made endovascular thrombectomy first-line treatment for selected acute ischemic stroke patients, the treatment was available at barely more than one-third of all U.S. stroke centers, available within 30-minute access to just over 30% of Americans, and available within 15-minute access to one-fifth of U.S. residents, based on information in a comprehensive U.S. database.
These numbers showed that “current direct EVT [endovascular thrombectomy] access in the United States is suboptimal under predominate EMS routing protocols,” Amrou Sarraj, MD, and his associates wrote in an article published online in Stroke on Feb. 12. “Only in eight states did the coverage exceed 25% of the population, and nine states had coverage for less than 10% of the population. These results reflect limited access to an effective treatment modality that would improve clinical outcomes in patients with large strokes and prevent potentially devastating disability,” wrote Dr. Sarraj, chief of the general neurology service at Memorial-Hermann Hospital in Houston and coauthors.
Their analysis of data collected in 2017 by the Medicare Provider Analysis and Review (MEDPAR) database, maintained by the Centers for Medicare & Medicaid Services, identified two apparently effective ways to improve EVT access for acute ischemic stroke patients: First, systematically divert patients to a nearby center that offers EVT even when it means bypassing a closer stroke center that does not perform EVT when the added travel time is less than 15 minutes. Second, convert selected stroke centers that currently do not perform EVT into centers that do. Between these two approaches, the strategy of having ambulances bypass stroke centers that do not perform EVT and continuing to ones that do generally has the greater potential to boost access, the authors found. They based their analysis exclusively on their calculations of expected consequences rather than actual experience.
The calculations showed that bypassing non-EVT centers when the added bypass time computed to less than 15 minutes linked with an anticipated overall U.S. gain in access of about 17%, or 52 million people, extending the ability of acute ischemic stroke patients able to quickly reach an EVT center to about 37% of the American public. The second approach to boost access, converting the top 10% of stroke centers based on case volume that currently do not provide EVT to centers that do offer it, would result in expanded access for about 23 million additional Americans, raising the total with access to about 27% of the public, the new report said.
As part of this analysis, the MEDPAR data identified 1,941 U.S. centers providing stroke services during 2017, of which 713 (37%) had performed at least one EVT procedure. By comparison, 2015 MEDPAR data showed 577 U.S. stroke centers performing EVT, indicating that during the 2-3 years following several reports in early 2015 on the net benefits of EVT for acute ischemic stroke patients, the number of U.S. stroke centers offering this treatment had grown by a relative 24%. Based on the locations of the stroke centers that made EVT available in 2017, Dr. Sarraj and coauthors calculated that the 713 EVT-capable stroke centers provided emergency access within a 15-minute ground-ambulance trip for 61 million Americans (20% of the U.S. population), and within a 30-minute ground-transport trip to 95 million residents (31%).
Boosting these numbers by implementing a systematic bypass of stroke patients past non-EVT stroke centers to nearby centers that are EVT capable “has the benefit of ease of implementation and requires less time and resources,” the authors said. However, they also noted the heterogeneity of circumstances based on variables like population density and stroke center distribution, which means that in some locations the most effective way to boost access would be by increasing the number of stroke centers that provide EVT.
In 2018, Dr. Sarraj and associates reported results from a similar analysis of MEDPAR data that used 30-minute and 60-minute ground-transport times as the criteria for their calculations.
The study received no commercial funding. Dr. Sarraj reported receiving research funding from Stryker Neurovascular outside of this work. One coauthor reported serving in roles for the University of Texas Health System for which the institution has been funded via various industry and government grants, and another coauthor reported receiving research funding from the Patient-Centered Outcomes Research Institute, the National Institutes of Health, Genentech, and CSL Behring, as well as consulting fees from Frazer Ltd.
SOURCE: Sarraj A et al. Stroke. 2020 Feb 12. doi: 10.1161/STROKEAHA.120.028850.
In 2017, roughly 3 years after evidence from several studies made endovascular thrombectomy first-line treatment for selected acute ischemic stroke patients, the treatment was available at barely more than one-third of all U.S. stroke centers, available within 30-minute access to just over 30% of Americans, and available within 15-minute access to one-fifth of U.S. residents, based on information in a comprehensive U.S. database.
These numbers showed that “current direct EVT [endovascular thrombectomy] access in the United States is suboptimal under predominate EMS routing protocols,” Amrou Sarraj, MD, and his associates wrote in an article published online in Stroke on Feb. 12. “Only in eight states did the coverage exceed 25% of the population, and nine states had coverage for less than 10% of the population. These results reflect limited access to an effective treatment modality that would improve clinical outcomes in patients with large strokes and prevent potentially devastating disability,” wrote Dr. Sarraj, chief of the general neurology service at Memorial-Hermann Hospital in Houston and coauthors.
Their analysis of data collected in 2017 by the Medicare Provider Analysis and Review (MEDPAR) database, maintained by the Centers for Medicare & Medicaid Services, identified two apparently effective ways to improve EVT access for acute ischemic stroke patients: First, systematically divert patients to a nearby center that offers EVT even when it means bypassing a closer stroke center that does not perform EVT when the added travel time is less than 15 minutes. Second, convert selected stroke centers that currently do not perform EVT into centers that do. Between these two approaches, the strategy of having ambulances bypass stroke centers that do not perform EVT and continuing to ones that do generally has the greater potential to boost access, the authors found. They based their analysis exclusively on their calculations of expected consequences rather than actual experience.
The calculations showed that bypassing non-EVT centers when the added bypass time computed to less than 15 minutes linked with an anticipated overall U.S. gain in access of about 17%, or 52 million people, extending the ability of acute ischemic stroke patients able to quickly reach an EVT center to about 37% of the American public. The second approach to boost access, converting the top 10% of stroke centers based on case volume that currently do not provide EVT to centers that do offer it, would result in expanded access for about 23 million additional Americans, raising the total with access to about 27% of the public, the new report said.
As part of this analysis, the MEDPAR data identified 1,941 U.S. centers providing stroke services during 2017, of which 713 (37%) had performed at least one EVT procedure. By comparison, 2015 MEDPAR data showed 577 U.S. stroke centers performing EVT, indicating that during the 2-3 years following several reports in early 2015 on the net benefits of EVT for acute ischemic stroke patients, the number of U.S. stroke centers offering this treatment had grown by a relative 24%. Based on the locations of the stroke centers that made EVT available in 2017, Dr. Sarraj and coauthors calculated that the 713 EVT-capable stroke centers provided emergency access within a 15-minute ground-ambulance trip for 61 million Americans (20% of the U.S. population), and within a 30-minute ground-transport trip to 95 million residents (31%).
Boosting these numbers by implementing a systematic bypass of stroke patients past non-EVT stroke centers to nearby centers that are EVT capable “has the benefit of ease of implementation and requires less time and resources,” the authors said. However, they also noted the heterogeneity of circumstances based on variables like population density and stroke center distribution, which means that in some locations the most effective way to boost access would be by increasing the number of stroke centers that provide EVT.
In 2018, Dr. Sarraj and associates reported results from a similar analysis of MEDPAR data that used 30-minute and 60-minute ground-transport times as the criteria for their calculations.
The study received no commercial funding. Dr. Sarraj reported receiving research funding from Stryker Neurovascular outside of this work. One coauthor reported serving in roles for the University of Texas Health System for which the institution has been funded via various industry and government grants, and another coauthor reported receiving research funding from the Patient-Centered Outcomes Research Institute, the National Institutes of Health, Genentech, and CSL Behring, as well as consulting fees from Frazer Ltd.
SOURCE: Sarraj A et al. Stroke. 2020 Feb 12. doi: 10.1161/STROKEAHA.120.028850.
In 2017, roughly 3 years after evidence from several studies made endovascular thrombectomy first-line treatment for selected acute ischemic stroke patients, the treatment was available at barely more than one-third of all U.S. stroke centers, available within 30-minute access to just over 30% of Americans, and available within 15-minute access to one-fifth of U.S. residents, based on information in a comprehensive U.S. database.
These numbers showed that “current direct EVT [endovascular thrombectomy] access in the United States is suboptimal under predominate EMS routing protocols,” Amrou Sarraj, MD, and his associates wrote in an article published online in Stroke on Feb. 12. “Only in eight states did the coverage exceed 25% of the population, and nine states had coverage for less than 10% of the population. These results reflect limited access to an effective treatment modality that would improve clinical outcomes in patients with large strokes and prevent potentially devastating disability,” wrote Dr. Sarraj, chief of the general neurology service at Memorial-Hermann Hospital in Houston and coauthors.
Their analysis of data collected in 2017 by the Medicare Provider Analysis and Review (MEDPAR) database, maintained by the Centers for Medicare & Medicaid Services, identified two apparently effective ways to improve EVT access for acute ischemic stroke patients: First, systematically divert patients to a nearby center that offers EVT even when it means bypassing a closer stroke center that does not perform EVT when the added travel time is less than 15 minutes. Second, convert selected stroke centers that currently do not perform EVT into centers that do. Between these two approaches, the strategy of having ambulances bypass stroke centers that do not perform EVT and continuing to ones that do generally has the greater potential to boost access, the authors found. They based their analysis exclusively on their calculations of expected consequences rather than actual experience.
The calculations showed that bypassing non-EVT centers when the added bypass time computed to less than 15 minutes linked with an anticipated overall U.S. gain in access of about 17%, or 52 million people, extending the ability of acute ischemic stroke patients able to quickly reach an EVT center to about 37% of the American public. The second approach to boost access, converting the top 10% of stroke centers based on case volume that currently do not provide EVT to centers that do offer it, would result in expanded access for about 23 million additional Americans, raising the total with access to about 27% of the public, the new report said.
As part of this analysis, the MEDPAR data identified 1,941 U.S. centers providing stroke services during 2017, of which 713 (37%) had performed at least one EVT procedure. By comparison, 2015 MEDPAR data showed 577 U.S. stroke centers performing EVT, indicating that during the 2-3 years following several reports in early 2015 on the net benefits of EVT for acute ischemic stroke patients, the number of U.S. stroke centers offering this treatment had grown by a relative 24%. Based on the locations of the stroke centers that made EVT available in 2017, Dr. Sarraj and coauthors calculated that the 713 EVT-capable stroke centers provided emergency access within a 15-minute ground-ambulance trip for 61 million Americans (20% of the U.S. population), and within a 30-minute ground-transport trip to 95 million residents (31%).
Boosting these numbers by implementing a systematic bypass of stroke patients past non-EVT stroke centers to nearby centers that are EVT capable “has the benefit of ease of implementation and requires less time and resources,” the authors said. However, they also noted the heterogeneity of circumstances based on variables like population density and stroke center distribution, which means that in some locations the most effective way to boost access would be by increasing the number of stroke centers that provide EVT.
In 2018, Dr. Sarraj and associates reported results from a similar analysis of MEDPAR data that used 30-minute and 60-minute ground-transport times as the criteria for their calculations.
The study received no commercial funding. Dr. Sarraj reported receiving research funding from Stryker Neurovascular outside of this work. One coauthor reported serving in roles for the University of Texas Health System for which the institution has been funded via various industry and government grants, and another coauthor reported receiving research funding from the Patient-Centered Outcomes Research Institute, the National Institutes of Health, Genentech, and CSL Behring, as well as consulting fees from Frazer Ltd.
SOURCE: Sarraj A et al. Stroke. 2020 Feb 12. doi: 10.1161/STROKEAHA.120.028850.
FROM STROKE
More conflicting evidence on paclitaxel devices in PAD
The controversy regarding the safety of treating peripheral artery disease (PAD) with paclitaxel-coated devices has only deepened in the new year, with two recent studies suggesting opposite safety findings.
The debate began with a 2018 meta-analysis showing a late mortality signal associated with paclitaxel drug-coated balloons (DCBs) that sent reverberations through the interventional cardiology community (J Am Heart Assoc. 2018 Dec 18;7[24]:e011245).
Now, in a new meta-analysis involving eight randomized controlled trials (RCTs) and more than 1,400 patients with critical limb ischemia (CLI), the same researchers found significantly more early amputations and deaths in those treated with DCB below the knee, compared with conventional balloon angioplasty.
“The findings of our latest report add to previous evidence underpinning major safety concerns around use of paclitaxel in lower limb angioplasties – increased long-term patient mortality in cases of intermittent claudication,” lead author Konstantinos Katsanos MD, MSc, PhD, Patras University Hospital, Greece, said in an interview.
By contrast, a retrospective study of insurance claims in Germany showed no heightened mortality with paclitaxel-coated balloons and stents, compared with uncoated devices, in close to 38,000 patients with PAD.
On the contrary, use of paclitaxel-coated devices was associated with higher long-term survival, better amputation-free survival (AFS), and lower rates of major cardiovascular events in the treatment of chronic limb-threatening ischemia (CLTI).
These findings “emphasize the difference between population-based evidence and randomized trials,” lead author Christian-Alexander Behrendt, MD, University Medical Center Hamburg-Eppendorf, Germany, said in an interview.
Downstream “showers”
In the new meta-analysis led by Dr. Katsanos, published online Jan. 15, the 1,420 patients were treated with five different DCBs and 97% had CLI (J Vasc Intervent Radiol 2020 Feb;31[2]:202-12).
In up to 1-year follow-up, the paclitaxel DCB group had fewer target lesion revascularizations (TLR) than those of the uncoated device group (11.8% vs. 25.6%; risk ratio, 0.53; 95% confidence interval, 0.35-0.81) but worse AFS (13.7% vs. 9.4%; hazard ratio [HR], 1.52; 95% CI, 1.12-2.07).
The latter finding was driven by nonsignificant increased risks for all-cause death (odds ratio [OR], 1.39; 95% CI, 0.94-2.07) and major amputations (OR, 1.63; 95% CI, 0.92-2.90).
In dose-subgroup analyses, AFS was significantly worse in cases with high-dose (3.0-3.5 mcg/mm2) devices, but not in the single trial with a low-dose DCB (2.0 mcg/mm2).
“Considering the well-described downstream ‘showers’ of paclitaxel particles with current drug-coated balloons, we hypothesize that nontarget paclitaxel embolization is a plausible mechanism for distal foot and systemic toxicity,” Dr. Katsanos said.
Short time frame
Eric Secemsky, MD, of Harvard Medical School, and director of vascular intervention at Beth Israel Deaconess Medical Center, Boston, suggested in an interview that this theorized mechanism of harm in below-the-knee procedures could potentially shed light on a similar mechanism at play in above-the-knee procedures.
“We didn’t understand why people could potentially be dying in above-the-knee [procedures], and the suggestion here is that these devices might perhaps be causing particular embolization or maybe delayed wound healing,” Dr. Secemsky speculated.
However, “I don’t know that this is true, so I am cautious to say this is true,” he emphasized.
Dr. Secemsky said a strength of the Katsanos analysis is that the RCTs included more than 1,000 patients, but noted that it is hard to vet the quality and rigor of the data, as some of the studies have not yet been published. He also noted that paclitaxel-coated devices are not approved by the Food and Drug Administration in the United States for below-the-knee procedures.
Moreover, he continued, “two studies were driving the signal of harm: the IN.PACT DEEP, which included an iteration of their DCB that is no longer being tested; and the unpublished SINGA-PACLI trial. Those studies contributed most of the adverse events seen in this meta-analysis.”
In addition, the trials had different lengths of follow-up (6-12 months), he said. “Thus, the five trials with data available to 12 months are driving the 1-year findings, whereas three RCTs, including the primary RCT showing safety [Lutonix-BTK trial], only contribute data to 6 months.”
For this reason, “we are not too excited about this meta-analysis as of now, [because] all it tells us is that we need more data to support the safety of drug-coated devices in this population,” Dr. Secemsky said.
Dr. Katsanos explained that, “to address the differences in follow-up period and number of cases lost to follow-up, the primary endpoint was calculated on the log-hazard scale and expressed as a hazard ratio, as recommended for time-to-event outcomes.”
He highlighted that a short-term time frame of 6 months to 1 year was chosen “because it is clinically relevant to limb-threatening CLI.”
Sensitivity tests also “showed consistent direction and magnitude of the summary treatment effects in case of both AFS and freedom from TLR,” Dr. Katsanos emphasized.
Lower mortality, fewer amputations
The second study, published online Jan. 8, drew on health insurance claims in the German BARMER database to analyze 37,914 patients (mean age, 73.3 years, 49% female) and 21,546 propensity-score-matched patients with symptomatic CLTI or intermittent claudication (IC) with an index revascularization during 2010-2018 (Eur J Vasc Endovasc Surg. 2020 Jan 8. doi: 10.1016/j.ejvs.2019.12.034).
Patients were first stratified by CLTI or IC, and then by balloon vs. stent use. Paclitaxel-coated devices were then compared with uncoated devices within each stratum. The primary outcome was all-cause mortality at the end of follow-up.
From 2010 to 2018, the annual use of paclitaxel-coated devices increased dramatically from 3% to 39% in the CLTI group and from 4% to 48% in the IC group (P less than .001 for both).
A total of 2,454 deaths occurred within 5 years of follow-up (median, 2.7 years; longest, 8 years).
A Cox proportional hazards model (based on propensity-score-matched cohorts at 5 years) showed that, compared with uncoated devices, use of paclitaxel-coated devices in the CLTI group was associated with several improvements:
- Overall survival: HR, 0.83; 95% CI, 0.77-0.90.
- Amputation-free survival: HR, 0.85; 95% CI, 0.78-0.91.
- Major cardiovascular events: HR, 0.82; 95% CI, 0.77-0.88.
In the IC group, mortality was significantly better with DCB (HR, 0.87; 95% CI, 0.76-0.99) or a combination of DCB and drug-eluting stents (HR, 0.88; 95% CI, 0.80-0.98) than with uncoated devices, but similar for DES alone (HR, 0.91; 95% CI, 0.77-1.08).
No benefit was found for paclitaxel-coated devices in the IC group for AFS (HR, 0.91; 95% CI, 0.82-1.00) or major cardiovascular events (HR, 0.93; 95% CI, 0.87-1.00).
The authors acknowledge that “unmeasured confounding” may partly explain the results. It may be that patients revascularized with DCB or DES “are more likely to be treated in highly specialized trial centers with clear follow-up protocol.”
Moreover, these patients may have received “the best treatment,” including statin therapy, added Dr. Behrendt.
More evidence needed
Dr. Secemsky, who was not involved with either study, said the German investigators “did a wonderful job with this analysis in a large population of several thousand patients, showing nicely that after accounting for differences in comorbidities, the patients had no evidence of harm with [paclitaxel-coated] devices through 5 years.”
However, he cautioned, median follow-up time was just over 2 years. “Although the investigators had data all the way out to 5 years, over time, the number of patients contributing data became smaller, which results in more uncertainty with these longer-term findings,” he said. “As such, we still need to look at additional long-term data in this patient population to confirm the safety of these devices.”
At present, the “major consideration we want to address is whether it’s safe to use these devices, and we’re undertaking these analyses to examine safety, not to see if they improve mortality,” although the present study “has a suggestion of mortality benefit,” Dr. Secemsky said.
Dr. Katsanos added that paclitaxel-coated balloons “remain under investigation for below-knee arteries and critical limb ischemia,” with “a few randomized controlled trials on the way.”
“We need definitive evidence from high-quality multicenter controlled trials that these devices may improve wound healing and limb salvage without any systemic mortality risk,” he said.
Dr. Katsanos receives personal fees from Boston Scientific and Philips Healthcare. The study by Dr. Behrendt was part of the IDOMENEO project funded by the German Joint Federal Committee. Dr. Behrendt reports no relevant financial relationships. Dr. Secemsky reports institutional grants from Cook Medical, BD Bard, Medtronic, Beth Israel Deaconess Medical Center, and Boston Scientific, and reports consultancy for Cook Medical, BD Bard, and Medtronic.
This article first appeared on Medscape.com.
The controversy regarding the safety of treating peripheral artery disease (PAD) with paclitaxel-coated devices has only deepened in the new year, with two recent studies suggesting opposite safety findings.
The debate began with a 2018 meta-analysis showing a late mortality signal associated with paclitaxel drug-coated balloons (DCBs) that sent reverberations through the interventional cardiology community (J Am Heart Assoc. 2018 Dec 18;7[24]:e011245).
Now, in a new meta-analysis involving eight randomized controlled trials (RCTs) and more than 1,400 patients with critical limb ischemia (CLI), the same researchers found significantly more early amputations and deaths in those treated with DCB below the knee, compared with conventional balloon angioplasty.
“The findings of our latest report add to previous evidence underpinning major safety concerns around use of paclitaxel in lower limb angioplasties – increased long-term patient mortality in cases of intermittent claudication,” lead author Konstantinos Katsanos MD, MSc, PhD, Patras University Hospital, Greece, said in an interview.
By contrast, a retrospective study of insurance claims in Germany showed no heightened mortality with paclitaxel-coated balloons and stents, compared with uncoated devices, in close to 38,000 patients with PAD.
On the contrary, use of paclitaxel-coated devices was associated with higher long-term survival, better amputation-free survival (AFS), and lower rates of major cardiovascular events in the treatment of chronic limb-threatening ischemia (CLTI).
These findings “emphasize the difference between population-based evidence and randomized trials,” lead author Christian-Alexander Behrendt, MD, University Medical Center Hamburg-Eppendorf, Germany, said in an interview.
Downstream “showers”
In the new meta-analysis led by Dr. Katsanos, published online Jan. 15, the 1,420 patients were treated with five different DCBs and 97% had CLI (J Vasc Intervent Radiol 2020 Feb;31[2]:202-12).
In up to 1-year follow-up, the paclitaxel DCB group had fewer target lesion revascularizations (TLR) than those of the uncoated device group (11.8% vs. 25.6%; risk ratio, 0.53; 95% confidence interval, 0.35-0.81) but worse AFS (13.7% vs. 9.4%; hazard ratio [HR], 1.52; 95% CI, 1.12-2.07).
The latter finding was driven by nonsignificant increased risks for all-cause death (odds ratio [OR], 1.39; 95% CI, 0.94-2.07) and major amputations (OR, 1.63; 95% CI, 0.92-2.90).
In dose-subgroup analyses, AFS was significantly worse in cases with high-dose (3.0-3.5 mcg/mm2) devices, but not in the single trial with a low-dose DCB (2.0 mcg/mm2).
“Considering the well-described downstream ‘showers’ of paclitaxel particles with current drug-coated balloons, we hypothesize that nontarget paclitaxel embolization is a plausible mechanism for distal foot and systemic toxicity,” Dr. Katsanos said.
Short time frame
Eric Secemsky, MD, of Harvard Medical School, and director of vascular intervention at Beth Israel Deaconess Medical Center, Boston, suggested in an interview that this theorized mechanism of harm in below-the-knee procedures could potentially shed light on a similar mechanism at play in above-the-knee procedures.
“We didn’t understand why people could potentially be dying in above-the-knee [procedures], and the suggestion here is that these devices might perhaps be causing particular embolization or maybe delayed wound healing,” Dr. Secemsky speculated.
However, “I don’t know that this is true, so I am cautious to say this is true,” he emphasized.
Dr. Secemsky said a strength of the Katsanos analysis is that the RCTs included more than 1,000 patients, but noted that it is hard to vet the quality and rigor of the data, as some of the studies have not yet been published. He also noted that paclitaxel-coated devices are not approved by the Food and Drug Administration in the United States for below-the-knee procedures.
Moreover, he continued, “two studies were driving the signal of harm: the IN.PACT DEEP, which included an iteration of their DCB that is no longer being tested; and the unpublished SINGA-PACLI trial. Those studies contributed most of the adverse events seen in this meta-analysis.”
In addition, the trials had different lengths of follow-up (6-12 months), he said. “Thus, the five trials with data available to 12 months are driving the 1-year findings, whereas three RCTs, including the primary RCT showing safety [Lutonix-BTK trial], only contribute data to 6 months.”
For this reason, “we are not too excited about this meta-analysis as of now, [because] all it tells us is that we need more data to support the safety of drug-coated devices in this population,” Dr. Secemsky said.
Dr. Katsanos explained that, “to address the differences in follow-up period and number of cases lost to follow-up, the primary endpoint was calculated on the log-hazard scale and expressed as a hazard ratio, as recommended for time-to-event outcomes.”
He highlighted that a short-term time frame of 6 months to 1 year was chosen “because it is clinically relevant to limb-threatening CLI.”
Sensitivity tests also “showed consistent direction and magnitude of the summary treatment effects in case of both AFS and freedom from TLR,” Dr. Katsanos emphasized.
Lower mortality, fewer amputations
The second study, published online Jan. 8, drew on health insurance claims in the German BARMER database to analyze 37,914 patients (mean age, 73.3 years, 49% female) and 21,546 propensity-score-matched patients with symptomatic CLTI or intermittent claudication (IC) with an index revascularization during 2010-2018 (Eur J Vasc Endovasc Surg. 2020 Jan 8. doi: 10.1016/j.ejvs.2019.12.034).
Patients were first stratified by CLTI or IC, and then by balloon vs. stent use. Paclitaxel-coated devices were then compared with uncoated devices within each stratum. The primary outcome was all-cause mortality at the end of follow-up.
From 2010 to 2018, the annual use of paclitaxel-coated devices increased dramatically from 3% to 39% in the CLTI group and from 4% to 48% in the IC group (P less than .001 for both).
A total of 2,454 deaths occurred within 5 years of follow-up (median, 2.7 years; longest, 8 years).
A Cox proportional hazards model (based on propensity-score-matched cohorts at 5 years) showed that, compared with uncoated devices, use of paclitaxel-coated devices in the CLTI group was associated with several improvements:
- Overall survival: HR, 0.83; 95% CI, 0.77-0.90.
- Amputation-free survival: HR, 0.85; 95% CI, 0.78-0.91.
- Major cardiovascular events: HR, 0.82; 95% CI, 0.77-0.88.
In the IC group, mortality was significantly better with DCB (HR, 0.87; 95% CI, 0.76-0.99) or a combination of DCB and drug-eluting stents (HR, 0.88; 95% CI, 0.80-0.98) than with uncoated devices, but similar for DES alone (HR, 0.91; 95% CI, 0.77-1.08).
No benefit was found for paclitaxel-coated devices in the IC group for AFS (HR, 0.91; 95% CI, 0.82-1.00) or major cardiovascular events (HR, 0.93; 95% CI, 0.87-1.00).
The authors acknowledge that “unmeasured confounding” may partly explain the results. It may be that patients revascularized with DCB or DES “are more likely to be treated in highly specialized trial centers with clear follow-up protocol.”
Moreover, these patients may have received “the best treatment,” including statin therapy, added Dr. Behrendt.
More evidence needed
Dr. Secemsky, who was not involved with either study, said the German investigators “did a wonderful job with this analysis in a large population of several thousand patients, showing nicely that after accounting for differences in comorbidities, the patients had no evidence of harm with [paclitaxel-coated] devices through 5 years.”
However, he cautioned, median follow-up time was just over 2 years. “Although the investigators had data all the way out to 5 years, over time, the number of patients contributing data became smaller, which results in more uncertainty with these longer-term findings,” he said. “As such, we still need to look at additional long-term data in this patient population to confirm the safety of these devices.”
At present, the “major consideration we want to address is whether it’s safe to use these devices, and we’re undertaking these analyses to examine safety, not to see if they improve mortality,” although the present study “has a suggestion of mortality benefit,” Dr. Secemsky said.
Dr. Katsanos added that paclitaxel-coated balloons “remain under investigation for below-knee arteries and critical limb ischemia,” with “a few randomized controlled trials on the way.”
“We need definitive evidence from high-quality multicenter controlled trials that these devices may improve wound healing and limb salvage without any systemic mortality risk,” he said.
Dr. Katsanos receives personal fees from Boston Scientific and Philips Healthcare. The study by Dr. Behrendt was part of the IDOMENEO project funded by the German Joint Federal Committee. Dr. Behrendt reports no relevant financial relationships. Dr. Secemsky reports institutional grants from Cook Medical, BD Bard, Medtronic, Beth Israel Deaconess Medical Center, and Boston Scientific, and reports consultancy for Cook Medical, BD Bard, and Medtronic.
This article first appeared on Medscape.com.
The controversy regarding the safety of treating peripheral artery disease (PAD) with paclitaxel-coated devices has only deepened in the new year, with two recent studies suggesting opposite safety findings.
The debate began with a 2018 meta-analysis showing a late mortality signal associated with paclitaxel drug-coated balloons (DCBs) that sent reverberations through the interventional cardiology community (J Am Heart Assoc. 2018 Dec 18;7[24]:e011245).
Now, in a new meta-analysis involving eight randomized controlled trials (RCTs) and more than 1,400 patients with critical limb ischemia (CLI), the same researchers found significantly more early amputations and deaths in those treated with DCB below the knee, compared with conventional balloon angioplasty.
“The findings of our latest report add to previous evidence underpinning major safety concerns around use of paclitaxel in lower limb angioplasties – increased long-term patient mortality in cases of intermittent claudication,” lead author Konstantinos Katsanos MD, MSc, PhD, Patras University Hospital, Greece, said in an interview.
By contrast, a retrospective study of insurance claims in Germany showed no heightened mortality with paclitaxel-coated balloons and stents, compared with uncoated devices, in close to 38,000 patients with PAD.
On the contrary, use of paclitaxel-coated devices was associated with higher long-term survival, better amputation-free survival (AFS), and lower rates of major cardiovascular events in the treatment of chronic limb-threatening ischemia (CLTI).
These findings “emphasize the difference between population-based evidence and randomized trials,” lead author Christian-Alexander Behrendt, MD, University Medical Center Hamburg-Eppendorf, Germany, said in an interview.
Downstream “showers”
In the new meta-analysis led by Dr. Katsanos, published online Jan. 15, the 1,420 patients were treated with five different DCBs and 97% had CLI (J Vasc Intervent Radiol 2020 Feb;31[2]:202-12).
In up to 1-year follow-up, the paclitaxel DCB group had fewer target lesion revascularizations (TLR) than those of the uncoated device group (11.8% vs. 25.6%; risk ratio, 0.53; 95% confidence interval, 0.35-0.81) but worse AFS (13.7% vs. 9.4%; hazard ratio [HR], 1.52; 95% CI, 1.12-2.07).
The latter finding was driven by nonsignificant increased risks for all-cause death (odds ratio [OR], 1.39; 95% CI, 0.94-2.07) and major amputations (OR, 1.63; 95% CI, 0.92-2.90).
In dose-subgroup analyses, AFS was significantly worse in cases with high-dose (3.0-3.5 mcg/mm2) devices, but not in the single trial with a low-dose DCB (2.0 mcg/mm2).
“Considering the well-described downstream ‘showers’ of paclitaxel particles with current drug-coated balloons, we hypothesize that nontarget paclitaxel embolization is a plausible mechanism for distal foot and systemic toxicity,” Dr. Katsanos said.
Short time frame
Eric Secemsky, MD, of Harvard Medical School, and director of vascular intervention at Beth Israel Deaconess Medical Center, Boston, suggested in an interview that this theorized mechanism of harm in below-the-knee procedures could potentially shed light on a similar mechanism at play in above-the-knee procedures.
“We didn’t understand why people could potentially be dying in above-the-knee [procedures], and the suggestion here is that these devices might perhaps be causing particular embolization or maybe delayed wound healing,” Dr. Secemsky speculated.
However, “I don’t know that this is true, so I am cautious to say this is true,” he emphasized.
Dr. Secemsky said a strength of the Katsanos analysis is that the RCTs included more than 1,000 patients, but noted that it is hard to vet the quality and rigor of the data, as some of the studies have not yet been published. He also noted that paclitaxel-coated devices are not approved by the Food and Drug Administration in the United States for below-the-knee procedures.
Moreover, he continued, “two studies were driving the signal of harm: the IN.PACT DEEP, which included an iteration of their DCB that is no longer being tested; and the unpublished SINGA-PACLI trial. Those studies contributed most of the adverse events seen in this meta-analysis.”
In addition, the trials had different lengths of follow-up (6-12 months), he said. “Thus, the five trials with data available to 12 months are driving the 1-year findings, whereas three RCTs, including the primary RCT showing safety [Lutonix-BTK trial], only contribute data to 6 months.”
For this reason, “we are not too excited about this meta-analysis as of now, [because] all it tells us is that we need more data to support the safety of drug-coated devices in this population,” Dr. Secemsky said.
Dr. Katsanos explained that, “to address the differences in follow-up period and number of cases lost to follow-up, the primary endpoint was calculated on the log-hazard scale and expressed as a hazard ratio, as recommended for time-to-event outcomes.”
He highlighted that a short-term time frame of 6 months to 1 year was chosen “because it is clinically relevant to limb-threatening CLI.”
Sensitivity tests also “showed consistent direction and magnitude of the summary treatment effects in case of both AFS and freedom from TLR,” Dr. Katsanos emphasized.
Lower mortality, fewer amputations
The second study, published online Jan. 8, drew on health insurance claims in the German BARMER database to analyze 37,914 patients (mean age, 73.3 years, 49% female) and 21,546 propensity-score-matched patients with symptomatic CLTI or intermittent claudication (IC) with an index revascularization during 2010-2018 (Eur J Vasc Endovasc Surg. 2020 Jan 8. doi: 10.1016/j.ejvs.2019.12.034).
Patients were first stratified by CLTI or IC, and then by balloon vs. stent use. Paclitaxel-coated devices were then compared with uncoated devices within each stratum. The primary outcome was all-cause mortality at the end of follow-up.
From 2010 to 2018, the annual use of paclitaxel-coated devices increased dramatically from 3% to 39% in the CLTI group and from 4% to 48% in the IC group (P less than .001 for both).
A total of 2,454 deaths occurred within 5 years of follow-up (median, 2.7 years; longest, 8 years).
A Cox proportional hazards model (based on propensity-score-matched cohorts at 5 years) showed that, compared with uncoated devices, use of paclitaxel-coated devices in the CLTI group was associated with several improvements:
- Overall survival: HR, 0.83; 95% CI, 0.77-0.90.
- Amputation-free survival: HR, 0.85; 95% CI, 0.78-0.91.
- Major cardiovascular events: HR, 0.82; 95% CI, 0.77-0.88.
In the IC group, mortality was significantly better with DCB (HR, 0.87; 95% CI, 0.76-0.99) or a combination of DCB and drug-eluting stents (HR, 0.88; 95% CI, 0.80-0.98) than with uncoated devices, but similar for DES alone (HR, 0.91; 95% CI, 0.77-1.08).
No benefit was found for paclitaxel-coated devices in the IC group for AFS (HR, 0.91; 95% CI, 0.82-1.00) or major cardiovascular events (HR, 0.93; 95% CI, 0.87-1.00).
The authors acknowledge that “unmeasured confounding” may partly explain the results. It may be that patients revascularized with DCB or DES “are more likely to be treated in highly specialized trial centers with clear follow-up protocol.”
Moreover, these patients may have received “the best treatment,” including statin therapy, added Dr. Behrendt.
More evidence needed
Dr. Secemsky, who was not involved with either study, said the German investigators “did a wonderful job with this analysis in a large population of several thousand patients, showing nicely that after accounting for differences in comorbidities, the patients had no evidence of harm with [paclitaxel-coated] devices through 5 years.”
However, he cautioned, median follow-up time was just over 2 years. “Although the investigators had data all the way out to 5 years, over time, the number of patients contributing data became smaller, which results in more uncertainty with these longer-term findings,” he said. “As such, we still need to look at additional long-term data in this patient population to confirm the safety of these devices.”
At present, the “major consideration we want to address is whether it’s safe to use these devices, and we’re undertaking these analyses to examine safety, not to see if they improve mortality,” although the present study “has a suggestion of mortality benefit,” Dr. Secemsky said.
Dr. Katsanos added that paclitaxel-coated balloons “remain under investigation for below-knee arteries and critical limb ischemia,” with “a few randomized controlled trials on the way.”
“We need definitive evidence from high-quality multicenter controlled trials that these devices may improve wound healing and limb salvage without any systemic mortality risk,” he said.
Dr. Katsanos receives personal fees from Boston Scientific and Philips Healthcare. The study by Dr. Behrendt was part of the IDOMENEO project funded by the German Joint Federal Committee. Dr. Behrendt reports no relevant financial relationships. Dr. Secemsky reports institutional grants from Cook Medical, BD Bard, Medtronic, Beth Israel Deaconess Medical Center, and Boston Scientific, and reports consultancy for Cook Medical, BD Bard, and Medtronic.
This article first appeared on Medscape.com.
Mobile stroke unit had clinical impact on EVT
In its first year of operation, a mobile stroke unit in Melbourne demonstrated substantial savings in time to commencement of both thrombolysis and endovascular thrombectomy (EVT), results from a prospective study showed.
“While previously published data from MSU [mobile stroke unit] services in Europe and North America show substantial reductions in time to thrombolysis of approximately 30-45 minutes, little is known about the clinical impact on EVT,” first author Henry Zhao, MBBS, and colleagues wrote in a study published in Stroke.
Launched in November 2017, the Melbourne MSU is based at a large comprehensive stroke center and operates with a 20-km radius, servicing about 1.7 million people within the city of Melbourne. It is staffed with an onboard neurologist or senior stroke fellow who provides primary assessment and treatment decisions, a stroke advanced practice nurse who provides clinical support and treatment administration, a clinician who provides CT imaging, and advanced life support and mobile intensive care paramedics who provide transport logistics and paramedicine support. For the current analysis, MSU patients who received reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment, which the researchers used quantile regression analysis to determine. Time savings were subsequently converted to disability-adjusted life years (DALY) avoiding using published estimates.
Dr. Zhao of the Melbourne Brain Centre and department of neurology at Royal Melbourne Hospital and his colleagues reported that, in its first year of operation, the Melbourne MSU administered prehospital thrombolysis to 100 patients with a mean age of nearly 74 years. More than half of the patients (62%) were male. Compared with controls, the median time savings per MSU patient was 26 minutes for dispatch to hospital arrival and 15 minutes for hospital arrival to thrombolysis (P less than .0010 for both associations). The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes.
Over the same time period, 41 MSU patients with a mean age of 76 years received EVT dispatch-to-treatment time saving of 51 minutes (P less than 0.001). This included a median time saving of 17 minutes for EVT hospital arrival to arterial puncture for MSU patients (P = .001). Overall estimated median DALYs saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT.
“The benefit in EVT patients was primarily driven by prehospital MSU diagnosis of large vessel occlusion, which enabled bypass of a local non-EVT center directly to a comprehensive stroke center in almost 50% of patients with large vessel occlusion,” the researchers wrote. “Even when patients were located close to an EVT center, MSU pre-notification and facilitated workflows achieved a reduction in hospital arrival to arterial puncture by one-third. Furthermore, the time saving was seen despite the majority of EVT patients receiving repeat imaging in hospital to visualize the extracranial circulation.”
The study is scheduled to be presented at the International Stroke Conference on Feb. 20.
The Melbourne MSU received funding from the Australian Commonwealth Government, Victorian State Government, Royal Melbourne Hospital Neurosciences Foundation, Stroke Foundation, the Florey Institute of Neurosciences and Mental Health, the University of Melbourne, Boehringer Ingelheim, and private donation. Dr. Zhao disclosed that he has received grants from the Australian Commonwealth Government and the University of Melbourne and personal fees from Boehringer Ingelheim.
SOURCE: Zhao H et al. Stroke. 2020 Feb 12. doi: 10.1161/strokeaha.119.027843.
In its first year of operation, a mobile stroke unit in Melbourne demonstrated substantial savings in time to commencement of both thrombolysis and endovascular thrombectomy (EVT), results from a prospective study showed.
“While previously published data from MSU [mobile stroke unit] services in Europe and North America show substantial reductions in time to thrombolysis of approximately 30-45 minutes, little is known about the clinical impact on EVT,” first author Henry Zhao, MBBS, and colleagues wrote in a study published in Stroke.
Launched in November 2017, the Melbourne MSU is based at a large comprehensive stroke center and operates with a 20-km radius, servicing about 1.7 million people within the city of Melbourne. It is staffed with an onboard neurologist or senior stroke fellow who provides primary assessment and treatment decisions, a stroke advanced practice nurse who provides clinical support and treatment administration, a clinician who provides CT imaging, and advanced life support and mobile intensive care paramedics who provide transport logistics and paramedicine support. For the current analysis, MSU patients who received reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment, which the researchers used quantile regression analysis to determine. Time savings were subsequently converted to disability-adjusted life years (DALY) avoiding using published estimates.
Dr. Zhao of the Melbourne Brain Centre and department of neurology at Royal Melbourne Hospital and his colleagues reported that, in its first year of operation, the Melbourne MSU administered prehospital thrombolysis to 100 patients with a mean age of nearly 74 years. More than half of the patients (62%) were male. Compared with controls, the median time savings per MSU patient was 26 minutes for dispatch to hospital arrival and 15 minutes for hospital arrival to thrombolysis (P less than .0010 for both associations). The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes.
Over the same time period, 41 MSU patients with a mean age of 76 years received EVT dispatch-to-treatment time saving of 51 minutes (P less than 0.001). This included a median time saving of 17 minutes for EVT hospital arrival to arterial puncture for MSU patients (P = .001). Overall estimated median DALYs saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT.
“The benefit in EVT patients was primarily driven by prehospital MSU diagnosis of large vessel occlusion, which enabled bypass of a local non-EVT center directly to a comprehensive stroke center in almost 50% of patients with large vessel occlusion,” the researchers wrote. “Even when patients were located close to an EVT center, MSU pre-notification and facilitated workflows achieved a reduction in hospital arrival to arterial puncture by one-third. Furthermore, the time saving was seen despite the majority of EVT patients receiving repeat imaging in hospital to visualize the extracranial circulation.”
The study is scheduled to be presented at the International Stroke Conference on Feb. 20.
The Melbourne MSU received funding from the Australian Commonwealth Government, Victorian State Government, Royal Melbourne Hospital Neurosciences Foundation, Stroke Foundation, the Florey Institute of Neurosciences and Mental Health, the University of Melbourne, Boehringer Ingelheim, and private donation. Dr. Zhao disclosed that he has received grants from the Australian Commonwealth Government and the University of Melbourne and personal fees from Boehringer Ingelheim.
SOURCE: Zhao H et al. Stroke. 2020 Feb 12. doi: 10.1161/strokeaha.119.027843.
In its first year of operation, a mobile stroke unit in Melbourne demonstrated substantial savings in time to commencement of both thrombolysis and endovascular thrombectomy (EVT), results from a prospective study showed.
“While previously published data from MSU [mobile stroke unit] services in Europe and North America show substantial reductions in time to thrombolysis of approximately 30-45 minutes, little is known about the clinical impact on EVT,” first author Henry Zhao, MBBS, and colleagues wrote in a study published in Stroke.
Launched in November 2017, the Melbourne MSU is based at a large comprehensive stroke center and operates with a 20-km radius, servicing about 1.7 million people within the city of Melbourne. It is staffed with an onboard neurologist or senior stroke fellow who provides primary assessment and treatment decisions, a stroke advanced practice nurse who provides clinical support and treatment administration, a clinician who provides CT imaging, and advanced life support and mobile intensive care paramedics who provide transport logistics and paramedicine support. For the current analysis, MSU patients who received reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment, which the researchers used quantile regression analysis to determine. Time savings were subsequently converted to disability-adjusted life years (DALY) avoiding using published estimates.
Dr. Zhao of the Melbourne Brain Centre and department of neurology at Royal Melbourne Hospital and his colleagues reported that, in its first year of operation, the Melbourne MSU administered prehospital thrombolysis to 100 patients with a mean age of nearly 74 years. More than half of the patients (62%) were male. Compared with controls, the median time savings per MSU patient was 26 minutes for dispatch to hospital arrival and 15 minutes for hospital arrival to thrombolysis (P less than .0010 for both associations). The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes.
Over the same time period, 41 MSU patients with a mean age of 76 years received EVT dispatch-to-treatment time saving of 51 minutes (P less than 0.001). This included a median time saving of 17 minutes for EVT hospital arrival to arterial puncture for MSU patients (P = .001). Overall estimated median DALYs saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT.
“The benefit in EVT patients was primarily driven by prehospital MSU diagnosis of large vessel occlusion, which enabled bypass of a local non-EVT center directly to a comprehensive stroke center in almost 50% of patients with large vessel occlusion,” the researchers wrote. “Even when patients were located close to an EVT center, MSU pre-notification and facilitated workflows achieved a reduction in hospital arrival to arterial puncture by one-third. Furthermore, the time saving was seen despite the majority of EVT patients receiving repeat imaging in hospital to visualize the extracranial circulation.”
The study is scheduled to be presented at the International Stroke Conference on Feb. 20.
The Melbourne MSU received funding from the Australian Commonwealth Government, Victorian State Government, Royal Melbourne Hospital Neurosciences Foundation, Stroke Foundation, the Florey Institute of Neurosciences and Mental Health, the University of Melbourne, Boehringer Ingelheim, and private donation. Dr. Zhao disclosed that he has received grants from the Australian Commonwealth Government and the University of Melbourne and personal fees from Boehringer Ingelheim.
SOURCE: Zhao H et al. Stroke. 2020 Feb 12. doi: 10.1161/strokeaha.119.027843.
FROM STROKE
Key clinical point: A mobile stroke unit (MSU) substantially reduced time to reperfusion therapies.
Major finding: Compared with controls, the median time savings per MSU patient was 26 minutes for dispatch to hospital arrival and 15 minutes for hospital arrival to thrombolysis (P less than .0010 for both associations).
Study details: A prospective study of 100 stroke patients.
Disclosures: The Melbourne MSU received funding from the Australian Commonwealth Government, Victorian State Government, Royal Melbourne Hospital Neurosciences Foundation, Stroke Foundation, the Florey Institute of Neurosciences and Mental Health, the University of Melbourne, Boehringer Ingelheim, and private donation. Dr. Zhao disclosed that he has received grants from the Australian Commonwealth Government and the University of Melbourne and personal fees from Boehringer Ingelheim.
Source: Zhao H et al. Stroke. 2020 Feb 12. doi: 10.1161/strokeaha.119.027843.
Who’ll get SAVR in 2020?
SNOWMASS, COLO. – The number of transcatheter aortic valve replacements (TAVRs) performed annually in the United States is forecast to rocket up from 75,000 in 2019 to 100,000 in 2020 in response to the procedure’s recent approval in low-surgical-risk patients with symptomatic aortic stenosis, Michael J. Mack, MD, said at the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
“In 2020, TAVR seems like a tsunami that’s totally overwhelming SAVR [surgical aortic valve replacement]. And the question is, after the wave hits shore, is there going to be anything left in the surgical arena?” asked Dr. Mack, who is medical director of cardiothoracic surgery and chairman of the Baylor Scott & White The Heart Hospital – Plano (Tex.) Research Center.
He answered his own question with a quote from Mark Twain: “Reports of my death are greatly exaggerated.”
The trend is clear: TAVR will take over the market for isolated aortic valve replacement in much the same way that endovascular abdominal aortic aneurysm repair (EVAR) has come to dominate open surgical repair by an 80:20 margin. And By one estimate, it could include some 270,000 individuals per year in North America and the European Union (Eur Heart J. 2018 Jul 21;39[28]:2635-42).
But there’s no need to shed a tear at the prospect of SAVR surgeons standing in unemployment lines. They will continue to have their hands full performing combined SAVR plus coronary artery bypass graft (CABG) procedures, SAVR plus mitral or tricuspid valve operations, and Bentall procedures, Dr. Mack predicted.
Who should get SAVR for aortic stenosis in 2020? For starters, he said, the sorts of patients who were excluded from the major TAVR-versus-SAVR randomized trials. The low-surgical-risk trials were restricted to patients who had symptomatic aortic stenosis involving a tricuspid valve, no left ventricular outflow tract calcium, no or minimal coronary artery disease (CAD), a relatively normal left ventricular ejection fraction, and an aortic valve anatomy suitable for TAVR. And, 92% of study participants were over age 65 years.
Dr. Mack called the evidence for the safety and effectiveness of TAVR “the most robust evidence base in the history of medical devices,” backed by nine U.S. trials and 8,000 randomized patients during the last dozen years. He has played a major role in developing that evidence base, having served most recently as cochair of the landmark PARTNER 3 trial, which demonstrated superiority for TAVR over SAVR in low-surgical-risk patients. But the evidence base doesn’t apply to patients not enrolled in the trials. So for the foreseeable future, patients younger than age 65 years should probably stick with SAVR, mainly because of the still-open question of tissue valve durability and TAVR’s high rate of associated conduction system impairment and need for new pacemaker implantation. Younger patients find permanent pacemakers particularly problematic, he noted.
Others who should stick with surgery include patients with bicuspid valves, especially when aortopathy is present, individuals with low-lying coronary arteries, patients with heavy calcium deposits at the left ventricular outflow tract, those with infective endocarditis or rheumatic valve disease, and patients with structural valve deterioration after a valve-in-valve TAVR.
“Once you get beyond the first valve-in-valve, the outcomes are not going to be good. Those patients should preferentially be considered for surgery. The results for valve-in-valve have been very disappointing, with a 33% all-cause mortality at 3 years in the PARTNER Aortic Valve-in-Valve Registry,” according to the surgeon.
In patients with aortic stenosis and CAD, the clinical decision making should be based on the coronary disease. In a patient with triple-vessel disease, diabetes, and/or a high Syntax score for whom the collaborative multidisciplinary heart team would recommend surgical revascularization if aortic stenosis wasn’t present, the most appropriate option is SAVR plus CABG. On the other hand, if the CAD is amenable to percutaneous coronary intervention (PCI) and the Syntax score is low, TAVR plus PCI is a safe and solid strategy, he continued.
In addition to the unresolved issue of tissue valve durability, another unanswered question pushing against universal adoption of TAVR involves the clinical implications of bioprosthetic valve leaflet thrombosis and the optimal antithrombotic therapy, both early and late. Leaflet thrombosis post-TAVR is common – as well as post-SAVR with bioprosthetic valves, albeit less so – but the lesions often come and go. Although there is a theoretical concern that they might be a precursor to leaflet destruction, at this point, their clinical significance remains unclear. In the recent GALILEO trial, TAVR patients randomized to low-dose rivaroxaban (Xarelto) plus aspirin showed fewer leaflet motion abnormalities and less leaflet thickening than did those on dual-antiplatelet therapy, but a significantly higher all-cause mortality (N Engl J Med 2020 Jan 9;382:120-9).
“I know that nowhere else in the body is thrombus a good thing, so thrombus in the valve can’t be a good thing. The only question is, how bad is it? And right now all we know is, some of our treatments for it are worse than the disease,” the surgeon commented.
Dr. Mack indicated that, at this time, clinical decision making in aortic stenosis should begin on the basis of patient age, which influences the key decision of whether to opt for a mechanical versus tissue replacement valve. For patients aged 50-70 years, shared decision making between the heart team and patient is appropriate. The evidence suggests SAVR with a mechanical valve is the better option, but many patients in this intermediate age group loathe the ideal of lifelong oral anticoagulation and favor a tissue valve.
For patients under age 50 years, the best evidence indicates that SAVR with a mechanical valve is clearly the best option; however, most young patients are instead opting for a tissue valve, even after being cautioned about the lingering uncertainty surrounding tissue valve durability, be it SAVR or TAVR. For patients over age 70 years, a tissue valve is the best choice based on the outcomes in PARTNER 3 and other low-surgical-risk trials. If the patient is younger than 65 years and wants a tissue valve, Dr. Mack thinks the best evidence-based option is SAVR. Above age 80 years, TAVR is the clear choice. Age 65-80 years is shared–decision making territory regarding TAVR versus SAVR.
Dr. Mack reported serving as a consultant to Gore and receiving research grants from Abbott Vascular, Edwards Lifesciences, and Medtronic.
SNOWMASS, COLO. – The number of transcatheter aortic valve replacements (TAVRs) performed annually in the United States is forecast to rocket up from 75,000 in 2019 to 100,000 in 2020 in response to the procedure’s recent approval in low-surgical-risk patients with symptomatic aortic stenosis, Michael J. Mack, MD, said at the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
“In 2020, TAVR seems like a tsunami that’s totally overwhelming SAVR [surgical aortic valve replacement]. And the question is, after the wave hits shore, is there going to be anything left in the surgical arena?” asked Dr. Mack, who is medical director of cardiothoracic surgery and chairman of the Baylor Scott & White The Heart Hospital – Plano (Tex.) Research Center.
He answered his own question with a quote from Mark Twain: “Reports of my death are greatly exaggerated.”
The trend is clear: TAVR will take over the market for isolated aortic valve replacement in much the same way that endovascular abdominal aortic aneurysm repair (EVAR) has come to dominate open surgical repair by an 80:20 margin. And By one estimate, it could include some 270,000 individuals per year in North America and the European Union (Eur Heart J. 2018 Jul 21;39[28]:2635-42).
But there’s no need to shed a tear at the prospect of SAVR surgeons standing in unemployment lines. They will continue to have their hands full performing combined SAVR plus coronary artery bypass graft (CABG) procedures, SAVR plus mitral or tricuspid valve operations, and Bentall procedures, Dr. Mack predicted.
Who should get SAVR for aortic stenosis in 2020? For starters, he said, the sorts of patients who were excluded from the major TAVR-versus-SAVR randomized trials. The low-surgical-risk trials were restricted to patients who had symptomatic aortic stenosis involving a tricuspid valve, no left ventricular outflow tract calcium, no or minimal coronary artery disease (CAD), a relatively normal left ventricular ejection fraction, and an aortic valve anatomy suitable for TAVR. And, 92% of study participants were over age 65 years.
Dr. Mack called the evidence for the safety and effectiveness of TAVR “the most robust evidence base in the history of medical devices,” backed by nine U.S. trials and 8,000 randomized patients during the last dozen years. He has played a major role in developing that evidence base, having served most recently as cochair of the landmark PARTNER 3 trial, which demonstrated superiority for TAVR over SAVR in low-surgical-risk patients. But the evidence base doesn’t apply to patients not enrolled in the trials. So for the foreseeable future, patients younger than age 65 years should probably stick with SAVR, mainly because of the still-open question of tissue valve durability and TAVR’s high rate of associated conduction system impairment and need for new pacemaker implantation. Younger patients find permanent pacemakers particularly problematic, he noted.
Others who should stick with surgery include patients with bicuspid valves, especially when aortopathy is present, individuals with low-lying coronary arteries, patients with heavy calcium deposits at the left ventricular outflow tract, those with infective endocarditis or rheumatic valve disease, and patients with structural valve deterioration after a valve-in-valve TAVR.
“Once you get beyond the first valve-in-valve, the outcomes are not going to be good. Those patients should preferentially be considered for surgery. The results for valve-in-valve have been very disappointing, with a 33% all-cause mortality at 3 years in the PARTNER Aortic Valve-in-Valve Registry,” according to the surgeon.
In patients with aortic stenosis and CAD, the clinical decision making should be based on the coronary disease. In a patient with triple-vessel disease, diabetes, and/or a high Syntax score for whom the collaborative multidisciplinary heart team would recommend surgical revascularization if aortic stenosis wasn’t present, the most appropriate option is SAVR plus CABG. On the other hand, if the CAD is amenable to percutaneous coronary intervention (PCI) and the Syntax score is low, TAVR plus PCI is a safe and solid strategy, he continued.
In addition to the unresolved issue of tissue valve durability, another unanswered question pushing against universal adoption of TAVR involves the clinical implications of bioprosthetic valve leaflet thrombosis and the optimal antithrombotic therapy, both early and late. Leaflet thrombosis post-TAVR is common – as well as post-SAVR with bioprosthetic valves, albeit less so – but the lesions often come and go. Although there is a theoretical concern that they might be a precursor to leaflet destruction, at this point, their clinical significance remains unclear. In the recent GALILEO trial, TAVR patients randomized to low-dose rivaroxaban (Xarelto) plus aspirin showed fewer leaflet motion abnormalities and less leaflet thickening than did those on dual-antiplatelet therapy, but a significantly higher all-cause mortality (N Engl J Med 2020 Jan 9;382:120-9).
“I know that nowhere else in the body is thrombus a good thing, so thrombus in the valve can’t be a good thing. The only question is, how bad is it? And right now all we know is, some of our treatments for it are worse than the disease,” the surgeon commented.
Dr. Mack indicated that, at this time, clinical decision making in aortic stenosis should begin on the basis of patient age, which influences the key decision of whether to opt for a mechanical versus tissue replacement valve. For patients aged 50-70 years, shared decision making between the heart team and patient is appropriate. The evidence suggests SAVR with a mechanical valve is the better option, but many patients in this intermediate age group loathe the ideal of lifelong oral anticoagulation and favor a tissue valve.
For patients under age 50 years, the best evidence indicates that SAVR with a mechanical valve is clearly the best option; however, most young patients are instead opting for a tissue valve, even after being cautioned about the lingering uncertainty surrounding tissue valve durability, be it SAVR or TAVR. For patients over age 70 years, a tissue valve is the best choice based on the outcomes in PARTNER 3 and other low-surgical-risk trials. If the patient is younger than 65 years and wants a tissue valve, Dr. Mack thinks the best evidence-based option is SAVR. Above age 80 years, TAVR is the clear choice. Age 65-80 years is shared–decision making territory regarding TAVR versus SAVR.
Dr. Mack reported serving as a consultant to Gore and receiving research grants from Abbott Vascular, Edwards Lifesciences, and Medtronic.
SNOWMASS, COLO. – The number of transcatheter aortic valve replacements (TAVRs) performed annually in the United States is forecast to rocket up from 75,000 in 2019 to 100,000 in 2020 in response to the procedure’s recent approval in low-surgical-risk patients with symptomatic aortic stenosis, Michael J. Mack, MD, said at the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
“In 2020, TAVR seems like a tsunami that’s totally overwhelming SAVR [surgical aortic valve replacement]. And the question is, after the wave hits shore, is there going to be anything left in the surgical arena?” asked Dr. Mack, who is medical director of cardiothoracic surgery and chairman of the Baylor Scott & White The Heart Hospital – Plano (Tex.) Research Center.
He answered his own question with a quote from Mark Twain: “Reports of my death are greatly exaggerated.”
The trend is clear: TAVR will take over the market for isolated aortic valve replacement in much the same way that endovascular abdominal aortic aneurysm repair (EVAR) has come to dominate open surgical repair by an 80:20 margin. And By one estimate, it could include some 270,000 individuals per year in North America and the European Union (Eur Heart J. 2018 Jul 21;39[28]:2635-42).
But there’s no need to shed a tear at the prospect of SAVR surgeons standing in unemployment lines. They will continue to have their hands full performing combined SAVR plus coronary artery bypass graft (CABG) procedures, SAVR plus mitral or tricuspid valve operations, and Bentall procedures, Dr. Mack predicted.
Who should get SAVR for aortic stenosis in 2020? For starters, he said, the sorts of patients who were excluded from the major TAVR-versus-SAVR randomized trials. The low-surgical-risk trials were restricted to patients who had symptomatic aortic stenosis involving a tricuspid valve, no left ventricular outflow tract calcium, no or minimal coronary artery disease (CAD), a relatively normal left ventricular ejection fraction, and an aortic valve anatomy suitable for TAVR. And, 92% of study participants were over age 65 years.
Dr. Mack called the evidence for the safety and effectiveness of TAVR “the most robust evidence base in the history of medical devices,” backed by nine U.S. trials and 8,000 randomized patients during the last dozen years. He has played a major role in developing that evidence base, having served most recently as cochair of the landmark PARTNER 3 trial, which demonstrated superiority for TAVR over SAVR in low-surgical-risk patients. But the evidence base doesn’t apply to patients not enrolled in the trials. So for the foreseeable future, patients younger than age 65 years should probably stick with SAVR, mainly because of the still-open question of tissue valve durability and TAVR’s high rate of associated conduction system impairment and need for new pacemaker implantation. Younger patients find permanent pacemakers particularly problematic, he noted.
Others who should stick with surgery include patients with bicuspid valves, especially when aortopathy is present, individuals with low-lying coronary arteries, patients with heavy calcium deposits at the left ventricular outflow tract, those with infective endocarditis or rheumatic valve disease, and patients with structural valve deterioration after a valve-in-valve TAVR.
“Once you get beyond the first valve-in-valve, the outcomes are not going to be good. Those patients should preferentially be considered for surgery. The results for valve-in-valve have been very disappointing, with a 33% all-cause mortality at 3 years in the PARTNER Aortic Valve-in-Valve Registry,” according to the surgeon.
In patients with aortic stenosis and CAD, the clinical decision making should be based on the coronary disease. In a patient with triple-vessel disease, diabetes, and/or a high Syntax score for whom the collaborative multidisciplinary heart team would recommend surgical revascularization if aortic stenosis wasn’t present, the most appropriate option is SAVR plus CABG. On the other hand, if the CAD is amenable to percutaneous coronary intervention (PCI) and the Syntax score is low, TAVR plus PCI is a safe and solid strategy, he continued.
In addition to the unresolved issue of tissue valve durability, another unanswered question pushing against universal adoption of TAVR involves the clinical implications of bioprosthetic valve leaflet thrombosis and the optimal antithrombotic therapy, both early and late. Leaflet thrombosis post-TAVR is common – as well as post-SAVR with bioprosthetic valves, albeit less so – but the lesions often come and go. Although there is a theoretical concern that they might be a precursor to leaflet destruction, at this point, their clinical significance remains unclear. In the recent GALILEO trial, TAVR patients randomized to low-dose rivaroxaban (Xarelto) plus aspirin showed fewer leaflet motion abnormalities and less leaflet thickening than did those on dual-antiplatelet therapy, but a significantly higher all-cause mortality (N Engl J Med 2020 Jan 9;382:120-9).
“I know that nowhere else in the body is thrombus a good thing, so thrombus in the valve can’t be a good thing. The only question is, how bad is it? And right now all we know is, some of our treatments for it are worse than the disease,” the surgeon commented.
Dr. Mack indicated that, at this time, clinical decision making in aortic stenosis should begin on the basis of patient age, which influences the key decision of whether to opt for a mechanical versus tissue replacement valve. For patients aged 50-70 years, shared decision making between the heart team and patient is appropriate. The evidence suggests SAVR with a mechanical valve is the better option, but many patients in this intermediate age group loathe the ideal of lifelong oral anticoagulation and favor a tissue valve.
For patients under age 50 years, the best evidence indicates that SAVR with a mechanical valve is clearly the best option; however, most young patients are instead opting for a tissue valve, even after being cautioned about the lingering uncertainty surrounding tissue valve durability, be it SAVR or TAVR. For patients over age 70 years, a tissue valve is the best choice based on the outcomes in PARTNER 3 and other low-surgical-risk trials. If the patient is younger than 65 years and wants a tissue valve, Dr. Mack thinks the best evidence-based option is SAVR. Above age 80 years, TAVR is the clear choice. Age 65-80 years is shared–decision making territory regarding TAVR versus SAVR.
Dr. Mack reported serving as a consultant to Gore and receiving research grants from Abbott Vascular, Edwards Lifesciences, and Medtronic.
EXPERT ANALYSIS FROM ACC SNOWMASS 2020
Heart rhythm data from wearables confounds EP practice
NATIONAL HARBOR, MD. – or other warnings that flagged a possible cardiac arrhythmia.
While the clinical community has yet to reach an evidence-based consensus on how to deal with this information, or even asymptomatic arrhythmias identified by more standard means, the American public is voting with their wrists. People seem to like collecting and reviewing readouts on their heart rhythm and other vital data, and then they often take their numbers to a physician, especially when their device suggests a possible problem.
“The whole paradigm of ordering a test only if you intend to act on the result has been flipped. People now get what they want directly, and our job is to guide them” after the fact. “You need to teach people what’s actionable and what’s not,” Mintu P. Turakhia, MD, said at the annual International AF Symposium.
“We’re in a situation where the ability of a sensor to detect things is separate from access to the health care system. They are no longer coupled; they are disjointed. People can create their own ICU in their house just by shopping online, but what do we do with this information, whether it’s an irregular heart rhythm or their whole genome?” asked Dr. Turakhia, executive director of the Center for Digital Health at Stanford (Calif.) University and director of cardiac electrophysiology at the VA Palo Alto (Calif.) Health Care System.
“The main challenge is people without a diagnosis who get a notification. How much monitoring should you do until you can say it was a false positive? We don’t know what to do, so we monitor them. People are trying to figure this out.” Dr. Turakhia said. Some people who seek out electrophysiologists this way “may not even have a primary care physician,” he noted.
The potential implications of widespread monitoring for heartbeat irregularities in the general public began to surface in a study that Dr. Turakhia helped run that collected wearable data from nearly 420,000 Americans. Results from the Apple Heart Study showed that, during a median 117 days of monitoring with a smart watch, 2,161 people (0.5%) received a report of an irregular pulse, which led to further investigations that eventually diagnosed atrial fibrillation (AFib) in 153 people of the 450 who underwent follow-up assessment (N Engl J Med. 2019 Nov 14;381[20]:1909-17). These results “raise questions” about the large number of people who underwent follow-up testing who did not have arrhythmia, Dr. Turakhia noted.
“The dissemination of wearables has been quite dramatic, and electrophysiologists end up owning this,” commented Jeremy N. Ruskin, MD, professor of medicine at Harvard Medical School and director emeritus of the cardiac arrhythmia service at Massachusetts General Hospital, both in Boston. “I get a ton of calls from people whom I wish never bought a smart watch, and they say ‘I have atrial fibrillation. What do I do?’ ”
To document the growth of this trend, Dr. Turakhia cited results from a survey he collaborated on, run by Stanford and Rock Health, that found a 33% ownership rate among American adults of a wearable device capable of collecting health data, and a 42% rate of people who tracked their health data with a device, app, journal, or log. Both of these rates more than doubled what a similar survey found in 2015.
The cardiac electrophysiology community took a first step toward addressing one aspect of this evolving situation. In early 2020, the Heart Rhythm Society and the Consumer Technology Association jointly issued a guidance document targeted at consumers that walks them through the kinds of information their wearable devices might collect and how to approach this information. The main message: If you have questions or concerns about your data, consult a clinician. What remains in short supply is guidance to clinicians on what to do when they see these patients.
“Until recently, device-detected AFib was the sole purview of electrophysiologists using implanted rhythm-monitoring devices. Now mobile and other devices raise issues [of asymptomatic AFib] for a much broader population,” noted Daniel E. Singer, MD, professor of medicine and epidemiology at Harvard and Massachusetts General Hospital. “The world of device-detected AFib now includes watches.”
Researchers have tried for years to better understand the stroke risk faced by patients with asymptomatic or subclinical AFib that’s detected by an implanted device, as in the ASSERT study of nearly 2,600 patients followed for a median of 2.5 years that found an increased stroke risk when the duration of individual, subclinical AFib episodes surpassed 24 hours (Eur Heart J. 2017 May 1;38[17]:1339-44). More recently, a study of AFib duration collected by implanted cardiac devices in nearly 22,000 Americans showed a relationship between stroke risk and both the duration of AFib episodes and the underlying risk of a person for stroke as measured by their CHA2DS2-VAScscore (Circulation. 2019 Nov 12;140[20]:1639-46). Just under 30% of patients in the study were diagnosed with AFib at entry.
The implications of asymptomatic episodes of AFib have so far been largely studied in people with an implanted cardiac device, which may have limited applicability to wearable users. In addition, the field has not yet fully sorted out the relationships between the duration of individual AFib episodes and overall AFib burden, and a person’s stroke risk and the window of time when the potential stroke-preventing benefits of anticoagulation outweigh its bleeding risk.
The results of trials now in progress that are examining the safety and efficacy of medical interventions designed to avert strokes in patients with asymptomatic AFib “will bear on the use of anticoagulants in a large group of patients,” including people with AFib detected by a wearable, Dr. Singer predicted.
The Apple Heart Study was sponsored Apple. Dr. Turakhia has received funding from Apple, and he has received honoraria or research funding from several other companies. Dr. Ruskin has been a consultant or adviser to several companies, is a steering committee member for Pfizer, and holds equity or options in Portola, Element Science, NewPace, Gilead, and InfoBionic. Dr. Singer has been a consultant and adviser to Boehringer Ingelheim, Bristol-Myers Squibb, Johnson & Johnson, Merck, and Pfizer, and he has received research grants from Bristol-Myers Squibb.
NATIONAL HARBOR, MD. – or other warnings that flagged a possible cardiac arrhythmia.
While the clinical community has yet to reach an evidence-based consensus on how to deal with this information, or even asymptomatic arrhythmias identified by more standard means, the American public is voting with their wrists. People seem to like collecting and reviewing readouts on their heart rhythm and other vital data, and then they often take their numbers to a physician, especially when their device suggests a possible problem.
“The whole paradigm of ordering a test only if you intend to act on the result has been flipped. People now get what they want directly, and our job is to guide them” after the fact. “You need to teach people what’s actionable and what’s not,” Mintu P. Turakhia, MD, said at the annual International AF Symposium.
“We’re in a situation where the ability of a sensor to detect things is separate from access to the health care system. They are no longer coupled; they are disjointed. People can create their own ICU in their house just by shopping online, but what do we do with this information, whether it’s an irregular heart rhythm or their whole genome?” asked Dr. Turakhia, executive director of the Center for Digital Health at Stanford (Calif.) University and director of cardiac electrophysiology at the VA Palo Alto (Calif.) Health Care System.
“The main challenge is people without a diagnosis who get a notification. How much monitoring should you do until you can say it was a false positive? We don’t know what to do, so we monitor them. People are trying to figure this out.” Dr. Turakhia said. Some people who seek out electrophysiologists this way “may not even have a primary care physician,” he noted.
The potential implications of widespread monitoring for heartbeat irregularities in the general public began to surface in a study that Dr. Turakhia helped run that collected wearable data from nearly 420,000 Americans. Results from the Apple Heart Study showed that, during a median 117 days of monitoring with a smart watch, 2,161 people (0.5%) received a report of an irregular pulse, which led to further investigations that eventually diagnosed atrial fibrillation (AFib) in 153 people of the 450 who underwent follow-up assessment (N Engl J Med. 2019 Nov 14;381[20]:1909-17). These results “raise questions” about the large number of people who underwent follow-up testing who did not have arrhythmia, Dr. Turakhia noted.
“The dissemination of wearables has been quite dramatic, and electrophysiologists end up owning this,” commented Jeremy N. Ruskin, MD, professor of medicine at Harvard Medical School and director emeritus of the cardiac arrhythmia service at Massachusetts General Hospital, both in Boston. “I get a ton of calls from people whom I wish never bought a smart watch, and they say ‘I have atrial fibrillation. What do I do?’ ”
To document the growth of this trend, Dr. Turakhia cited results from a survey he collaborated on, run by Stanford and Rock Health, that found a 33% ownership rate among American adults of a wearable device capable of collecting health data, and a 42% rate of people who tracked their health data with a device, app, journal, or log. Both of these rates more than doubled what a similar survey found in 2015.
The cardiac electrophysiology community took a first step toward addressing one aspect of this evolving situation. In early 2020, the Heart Rhythm Society and the Consumer Technology Association jointly issued a guidance document targeted at consumers that walks them through the kinds of information their wearable devices might collect and how to approach this information. The main message: If you have questions or concerns about your data, consult a clinician. What remains in short supply is guidance to clinicians on what to do when they see these patients.
“Until recently, device-detected AFib was the sole purview of electrophysiologists using implanted rhythm-monitoring devices. Now mobile and other devices raise issues [of asymptomatic AFib] for a much broader population,” noted Daniel E. Singer, MD, professor of medicine and epidemiology at Harvard and Massachusetts General Hospital. “The world of device-detected AFib now includes watches.”
Researchers have tried for years to better understand the stroke risk faced by patients with asymptomatic or subclinical AFib that’s detected by an implanted device, as in the ASSERT study of nearly 2,600 patients followed for a median of 2.5 years that found an increased stroke risk when the duration of individual, subclinical AFib episodes surpassed 24 hours (Eur Heart J. 2017 May 1;38[17]:1339-44). More recently, a study of AFib duration collected by implanted cardiac devices in nearly 22,000 Americans showed a relationship between stroke risk and both the duration of AFib episodes and the underlying risk of a person for stroke as measured by their CHA2DS2-VAScscore (Circulation. 2019 Nov 12;140[20]:1639-46). Just under 30% of patients in the study were diagnosed with AFib at entry.
The implications of asymptomatic episodes of AFib have so far been largely studied in people with an implanted cardiac device, which may have limited applicability to wearable users. In addition, the field has not yet fully sorted out the relationships between the duration of individual AFib episodes and overall AFib burden, and a person’s stroke risk and the window of time when the potential stroke-preventing benefits of anticoagulation outweigh its bleeding risk.
The results of trials now in progress that are examining the safety and efficacy of medical interventions designed to avert strokes in patients with asymptomatic AFib “will bear on the use of anticoagulants in a large group of patients,” including people with AFib detected by a wearable, Dr. Singer predicted.
The Apple Heart Study was sponsored Apple. Dr. Turakhia has received funding from Apple, and he has received honoraria or research funding from several other companies. Dr. Ruskin has been a consultant or adviser to several companies, is a steering committee member for Pfizer, and holds equity or options in Portola, Element Science, NewPace, Gilead, and InfoBionic. Dr. Singer has been a consultant and adviser to Boehringer Ingelheim, Bristol-Myers Squibb, Johnson & Johnson, Merck, and Pfizer, and he has received research grants from Bristol-Myers Squibb.
NATIONAL HARBOR, MD. – or other warnings that flagged a possible cardiac arrhythmia.
While the clinical community has yet to reach an evidence-based consensus on how to deal with this information, or even asymptomatic arrhythmias identified by more standard means, the American public is voting with their wrists. People seem to like collecting and reviewing readouts on their heart rhythm and other vital data, and then they often take their numbers to a physician, especially when their device suggests a possible problem.
“The whole paradigm of ordering a test only if you intend to act on the result has been flipped. People now get what they want directly, and our job is to guide them” after the fact. “You need to teach people what’s actionable and what’s not,” Mintu P. Turakhia, MD, said at the annual International AF Symposium.
“We’re in a situation where the ability of a sensor to detect things is separate from access to the health care system. They are no longer coupled; they are disjointed. People can create their own ICU in their house just by shopping online, but what do we do with this information, whether it’s an irregular heart rhythm or their whole genome?” asked Dr. Turakhia, executive director of the Center for Digital Health at Stanford (Calif.) University and director of cardiac electrophysiology at the VA Palo Alto (Calif.) Health Care System.
“The main challenge is people without a diagnosis who get a notification. How much monitoring should you do until you can say it was a false positive? We don’t know what to do, so we monitor them. People are trying to figure this out.” Dr. Turakhia said. Some people who seek out electrophysiologists this way “may not even have a primary care physician,” he noted.
The potential implications of widespread monitoring for heartbeat irregularities in the general public began to surface in a study that Dr. Turakhia helped run that collected wearable data from nearly 420,000 Americans. Results from the Apple Heart Study showed that, during a median 117 days of monitoring with a smart watch, 2,161 people (0.5%) received a report of an irregular pulse, which led to further investigations that eventually diagnosed atrial fibrillation (AFib) in 153 people of the 450 who underwent follow-up assessment (N Engl J Med. 2019 Nov 14;381[20]:1909-17). These results “raise questions” about the large number of people who underwent follow-up testing who did not have arrhythmia, Dr. Turakhia noted.
“The dissemination of wearables has been quite dramatic, and electrophysiologists end up owning this,” commented Jeremy N. Ruskin, MD, professor of medicine at Harvard Medical School and director emeritus of the cardiac arrhythmia service at Massachusetts General Hospital, both in Boston. “I get a ton of calls from people whom I wish never bought a smart watch, and they say ‘I have atrial fibrillation. What do I do?’ ”
To document the growth of this trend, Dr. Turakhia cited results from a survey he collaborated on, run by Stanford and Rock Health, that found a 33% ownership rate among American adults of a wearable device capable of collecting health data, and a 42% rate of people who tracked their health data with a device, app, journal, or log. Both of these rates more than doubled what a similar survey found in 2015.
The cardiac electrophysiology community took a first step toward addressing one aspect of this evolving situation. In early 2020, the Heart Rhythm Society and the Consumer Technology Association jointly issued a guidance document targeted at consumers that walks them through the kinds of information their wearable devices might collect and how to approach this information. The main message: If you have questions or concerns about your data, consult a clinician. What remains in short supply is guidance to clinicians on what to do when they see these patients.
“Until recently, device-detected AFib was the sole purview of electrophysiologists using implanted rhythm-monitoring devices. Now mobile and other devices raise issues [of asymptomatic AFib] for a much broader population,” noted Daniel E. Singer, MD, professor of medicine and epidemiology at Harvard and Massachusetts General Hospital. “The world of device-detected AFib now includes watches.”
Researchers have tried for years to better understand the stroke risk faced by patients with asymptomatic or subclinical AFib that’s detected by an implanted device, as in the ASSERT study of nearly 2,600 patients followed for a median of 2.5 years that found an increased stroke risk when the duration of individual, subclinical AFib episodes surpassed 24 hours (Eur Heart J. 2017 May 1;38[17]:1339-44). More recently, a study of AFib duration collected by implanted cardiac devices in nearly 22,000 Americans showed a relationship between stroke risk and both the duration of AFib episodes and the underlying risk of a person for stroke as measured by their CHA2DS2-VAScscore (Circulation. 2019 Nov 12;140[20]:1639-46). Just under 30% of patients in the study were diagnosed with AFib at entry.
The implications of asymptomatic episodes of AFib have so far been largely studied in people with an implanted cardiac device, which may have limited applicability to wearable users. In addition, the field has not yet fully sorted out the relationships between the duration of individual AFib episodes and overall AFib burden, and a person’s stroke risk and the window of time when the potential stroke-preventing benefits of anticoagulation outweigh its bleeding risk.
The results of trials now in progress that are examining the safety and efficacy of medical interventions designed to avert strokes in patients with asymptomatic AFib “will bear on the use of anticoagulants in a large group of patients,” including people with AFib detected by a wearable, Dr. Singer predicted.
The Apple Heart Study was sponsored Apple. Dr. Turakhia has received funding from Apple, and he has received honoraria or research funding from several other companies. Dr. Ruskin has been a consultant or adviser to several companies, is a steering committee member for Pfizer, and holds equity or options in Portola, Element Science, NewPace, Gilead, and InfoBionic. Dr. Singer has been a consultant and adviser to Boehringer Ingelheim, Bristol-Myers Squibb, Johnson & Johnson, Merck, and Pfizer, and he has received research grants from Bristol-Myers Squibb.
REPORTING FROM THE AF SYMPOSIUM 2020
Expanded indication for leadless pacemaker triples eligible patients
The U.S. Food and Drug Administration’s approval of an expanded indication for a leadless pacemaker for patients “who may benefit from maintenance of atrioventricular synchrony” will make this technology potentially available to nearly half of the Americans who need a pacemaker, roughly triple the number of patients who have been candidates for a leadless pacemaker up to now.
“This approval was huge. The complication rate with leadless pacemakers has been 63% less than the rate using pacemakers with transvenous leads,” said Larry A. Chinitz, MD, a cardiac electrophysiologist and a coinvestigator on some of the studies that led to the new indication. By expanding the types of patients suitable for leadless pacing “we’ll achieve AV [atrioventricular] synchrony in more patients with fewer complications,” said Dr. Chinitz, professor of medicine and director of the Cardiac Electrophysiology and Heart Rhythm Center at NYU Langone Health in New York.
Because the device is both leadless and requires no pocket owing to its small size and placement in a patient’s right ventricle, it has implications for potentially broadening the population that could benefit from the device, he said in an interview. “When we started with this pacemaker, it was limited to elderly patients with persistent atrial fibrillation who needed only ventricular pacing, a very small group,” just under 15% of the universe of patients who need pacemakers. The broadened indication, for patients with high-grade AV block who also have atrial function, makes it possible to think of using this safer and easier-to-place device in patients who need infrequent pacing, and in patients with multiple comorbidities that give them an increased complication risk, he said. The new indication means “you’re treating a much broader patient population, doing it more safely, and creating the foundation for expanding this technology.”
The Micra AV pacemaker uses the same basic design as the previously approved Micra Transcatheter Pacing System, which came onto the U.S. market in 2016 and provides single-chamber pacing. An accelerometer on the device allows it to detect atrial motion and thereby synchronize ventricular and atrial contractions, which led to the new indication. Although the Micra AV device looks similar to the original single-chamber model, it has an entirely new circuitry that prolongs battery life during dual-chamber pacing as well as new software that incorporates the accelerometer data, explained Robert Kowal, MD, a cardiac electrophysiologist, and vice president of medical affairs and chief medical officer of cardiac rhythm and heart failure at Medtronic in Minneapolis. The battery of the Micra AV is designed to last about 15 years, Dr. Chinitz noted.
Results from two studies that Dr. Chinitz helped run established the safety and efficacy of the device for dual-chamber pacing. The MARVEL (Micra Atrial Tracking Using a Ventricular Accelerometer) study included 64 patients who completed the study at 12 worldwide centers, which produced an average 80% AV synchrony in 33 patients with high-degree AV block (The other patients in the study had predominantly intrinsic AV conduction; Heart Rhythm. 2018 Sep;15[9]:1363-71). The MARVEL 2 study included 75 patients with either second- or third-degree AV block at 12 worldwide centers and showed that AV synchrony increased from an average of 27% without two-chamber pacing to 89% with the dual-chamber function turned on, and with 95% of patients achieving at least 70% AV synchrony (JACC Clin Electrophysiol. 2020 Jan;6[1]:94-106).
The 2016 indication for single-chamber pacing included patients with “high-grade” AV bloc with or without atrial fibrillation, typically patients for whom dual-chamber pacemaker was not a great option because of the risks for complication but with the downside of limited AV synchrony, a limitation now mitigated by the option of mechanical synchronization, Dr. Kowal said. The AV device remains intended for patients with high-grade AV node block, which means patients with second- or third-degree block, he added in an interview. The estimated prevalence of third-degree AV block among U.S. adults is about 0.02%, which translates into about 50,000 people; the estimated prevalence of second-degree AV block is much less, about 10% of the third-degree prevalence.
Despite the substantial cut in complications by a leadless and pocketless pacemaker, “some patients may still benefit from a traditional dual-chamber pacemaker,” specifically active patients who might sometimes get their heart rates up with exercise to levels of about 150 beats/min or higher, Dr. Kowal said. That’s because currently the programing algorithms used to synchronize the ventricle and atrium become less reliable at heart rates above 105 beats/min, he explained. However, the ability for mechanical synchronization to keep up at higher heart rates should improve as additional data are collected that can refine the algorithms. It’s also unusual for most patients who are pacemaker candidates to reach heart rates this high, he said.
The MARVEL and MARVEL 2 studies were sponsored by Medtronic, the company that markets Micra pacemakers. Dr. Chinitz has received fees and fellowship support from Medtronic, and has also received fees from Abbott, Biosense Webster, Biotronik, and Pfizer, and he has also received fellowship support from Biotronik and Boston Scientific. Dr. Kowal is a Medtronic employee.
The U.S. Food and Drug Administration’s approval of an expanded indication for a leadless pacemaker for patients “who may benefit from maintenance of atrioventricular synchrony” will make this technology potentially available to nearly half of the Americans who need a pacemaker, roughly triple the number of patients who have been candidates for a leadless pacemaker up to now.
“This approval was huge. The complication rate with leadless pacemakers has been 63% less than the rate using pacemakers with transvenous leads,” said Larry A. Chinitz, MD, a cardiac electrophysiologist and a coinvestigator on some of the studies that led to the new indication. By expanding the types of patients suitable for leadless pacing “we’ll achieve AV [atrioventricular] synchrony in more patients with fewer complications,” said Dr. Chinitz, professor of medicine and director of the Cardiac Electrophysiology and Heart Rhythm Center at NYU Langone Health in New York.
Because the device is both leadless and requires no pocket owing to its small size and placement in a patient’s right ventricle, it has implications for potentially broadening the population that could benefit from the device, he said in an interview. “When we started with this pacemaker, it was limited to elderly patients with persistent atrial fibrillation who needed only ventricular pacing, a very small group,” just under 15% of the universe of patients who need pacemakers. The broadened indication, for patients with high-grade AV block who also have atrial function, makes it possible to think of using this safer and easier-to-place device in patients who need infrequent pacing, and in patients with multiple comorbidities that give them an increased complication risk, he said. The new indication means “you’re treating a much broader patient population, doing it more safely, and creating the foundation for expanding this technology.”
The Micra AV pacemaker uses the same basic design as the previously approved Micra Transcatheter Pacing System, which came onto the U.S. market in 2016 and provides single-chamber pacing. An accelerometer on the device allows it to detect atrial motion and thereby synchronize ventricular and atrial contractions, which led to the new indication. Although the Micra AV device looks similar to the original single-chamber model, it has an entirely new circuitry that prolongs battery life during dual-chamber pacing as well as new software that incorporates the accelerometer data, explained Robert Kowal, MD, a cardiac electrophysiologist, and vice president of medical affairs and chief medical officer of cardiac rhythm and heart failure at Medtronic in Minneapolis. The battery of the Micra AV is designed to last about 15 years, Dr. Chinitz noted.
Results from two studies that Dr. Chinitz helped run established the safety and efficacy of the device for dual-chamber pacing. The MARVEL (Micra Atrial Tracking Using a Ventricular Accelerometer) study included 64 patients who completed the study at 12 worldwide centers, which produced an average 80% AV synchrony in 33 patients with high-degree AV block (The other patients in the study had predominantly intrinsic AV conduction; Heart Rhythm. 2018 Sep;15[9]:1363-71). The MARVEL 2 study included 75 patients with either second- or third-degree AV block at 12 worldwide centers and showed that AV synchrony increased from an average of 27% without two-chamber pacing to 89% with the dual-chamber function turned on, and with 95% of patients achieving at least 70% AV synchrony (JACC Clin Electrophysiol. 2020 Jan;6[1]:94-106).
The 2016 indication for single-chamber pacing included patients with “high-grade” AV bloc with or without atrial fibrillation, typically patients for whom dual-chamber pacemaker was not a great option because of the risks for complication but with the downside of limited AV synchrony, a limitation now mitigated by the option of mechanical synchronization, Dr. Kowal said. The AV device remains intended for patients with high-grade AV node block, which means patients with second- or third-degree block, he added in an interview. The estimated prevalence of third-degree AV block among U.S. adults is about 0.02%, which translates into about 50,000 people; the estimated prevalence of second-degree AV block is much less, about 10% of the third-degree prevalence.
Despite the substantial cut in complications by a leadless and pocketless pacemaker, “some patients may still benefit from a traditional dual-chamber pacemaker,” specifically active patients who might sometimes get their heart rates up with exercise to levels of about 150 beats/min or higher, Dr. Kowal said. That’s because currently the programing algorithms used to synchronize the ventricle and atrium become less reliable at heart rates above 105 beats/min, he explained. However, the ability for mechanical synchronization to keep up at higher heart rates should improve as additional data are collected that can refine the algorithms. It’s also unusual for most patients who are pacemaker candidates to reach heart rates this high, he said.
The MARVEL and MARVEL 2 studies were sponsored by Medtronic, the company that markets Micra pacemakers. Dr. Chinitz has received fees and fellowship support from Medtronic, and has also received fees from Abbott, Biosense Webster, Biotronik, and Pfizer, and he has also received fellowship support from Biotronik and Boston Scientific. Dr. Kowal is a Medtronic employee.
The U.S. Food and Drug Administration’s approval of an expanded indication for a leadless pacemaker for patients “who may benefit from maintenance of atrioventricular synchrony” will make this technology potentially available to nearly half of the Americans who need a pacemaker, roughly triple the number of patients who have been candidates for a leadless pacemaker up to now.
“This approval was huge. The complication rate with leadless pacemakers has been 63% less than the rate using pacemakers with transvenous leads,” said Larry A. Chinitz, MD, a cardiac electrophysiologist and a coinvestigator on some of the studies that led to the new indication. By expanding the types of patients suitable for leadless pacing “we’ll achieve AV [atrioventricular] synchrony in more patients with fewer complications,” said Dr. Chinitz, professor of medicine and director of the Cardiac Electrophysiology and Heart Rhythm Center at NYU Langone Health in New York.
Because the device is both leadless and requires no pocket owing to its small size and placement in a patient’s right ventricle, it has implications for potentially broadening the population that could benefit from the device, he said in an interview. “When we started with this pacemaker, it was limited to elderly patients with persistent atrial fibrillation who needed only ventricular pacing, a very small group,” just under 15% of the universe of patients who need pacemakers. The broadened indication, for patients with high-grade AV block who also have atrial function, makes it possible to think of using this safer and easier-to-place device in patients who need infrequent pacing, and in patients with multiple comorbidities that give them an increased complication risk, he said. The new indication means “you’re treating a much broader patient population, doing it more safely, and creating the foundation for expanding this technology.”
The Micra AV pacemaker uses the same basic design as the previously approved Micra Transcatheter Pacing System, which came onto the U.S. market in 2016 and provides single-chamber pacing. An accelerometer on the device allows it to detect atrial motion and thereby synchronize ventricular and atrial contractions, which led to the new indication. Although the Micra AV device looks similar to the original single-chamber model, it has an entirely new circuitry that prolongs battery life during dual-chamber pacing as well as new software that incorporates the accelerometer data, explained Robert Kowal, MD, a cardiac electrophysiologist, and vice president of medical affairs and chief medical officer of cardiac rhythm and heart failure at Medtronic in Minneapolis. The battery of the Micra AV is designed to last about 15 years, Dr. Chinitz noted.
Results from two studies that Dr. Chinitz helped run established the safety and efficacy of the device for dual-chamber pacing. The MARVEL (Micra Atrial Tracking Using a Ventricular Accelerometer) study included 64 patients who completed the study at 12 worldwide centers, which produced an average 80% AV synchrony in 33 patients with high-degree AV block (The other patients in the study had predominantly intrinsic AV conduction; Heart Rhythm. 2018 Sep;15[9]:1363-71). The MARVEL 2 study included 75 patients with either second- or third-degree AV block at 12 worldwide centers and showed that AV synchrony increased from an average of 27% without two-chamber pacing to 89% with the dual-chamber function turned on, and with 95% of patients achieving at least 70% AV synchrony (JACC Clin Electrophysiol. 2020 Jan;6[1]:94-106).
The 2016 indication for single-chamber pacing included patients with “high-grade” AV bloc with or without atrial fibrillation, typically patients for whom dual-chamber pacemaker was not a great option because of the risks for complication but with the downside of limited AV synchrony, a limitation now mitigated by the option of mechanical synchronization, Dr. Kowal said. The AV device remains intended for patients with high-grade AV node block, which means patients with second- or third-degree block, he added in an interview. The estimated prevalence of third-degree AV block among U.S. adults is about 0.02%, which translates into about 50,000 people; the estimated prevalence of second-degree AV block is much less, about 10% of the third-degree prevalence.
Despite the substantial cut in complications by a leadless and pocketless pacemaker, “some patients may still benefit from a traditional dual-chamber pacemaker,” specifically active patients who might sometimes get their heart rates up with exercise to levels of about 150 beats/min or higher, Dr. Kowal said. That’s because currently the programing algorithms used to synchronize the ventricle and atrium become less reliable at heart rates above 105 beats/min, he explained. However, the ability for mechanical synchronization to keep up at higher heart rates should improve as additional data are collected that can refine the algorithms. It’s also unusual for most patients who are pacemaker candidates to reach heart rates this high, he said.
The MARVEL and MARVEL 2 studies were sponsored by Medtronic, the company that markets Micra pacemakers. Dr. Chinitz has received fees and fellowship support from Medtronic, and has also received fees from Abbott, Biosense Webster, Biotronik, and Pfizer, and he has also received fellowship support from Biotronik and Boston Scientific. Dr. Kowal is a Medtronic employee.