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Esophageal retractor found handy tool in AF ablation
ORLANDO – A relatively simple mechanical tool to move the esophagus away from the energy delivered during ablation of atrial fibrillation (AF) does what it is supposed to do, according to data from a multicenter observational study presented at the AF Symposium 2017.
When esophageal temperature during the ablation procedure was monitored in 101 consecutive cases, no recording exceeded 38° C, according to Valay Parikh, MD, a clinical cardiac electrophysiology fellow working under Dhanunjaya Lakkireddy, MD, at the Kansas University Medical Center, Kansas City.
The tool is a stylet constructed from a nickel-titanium (nitinol) alloy. Malleable at room temperature, the stylet is inserted into an 18 Fr orogastric (OG) tube. Firmer at body temperature, the stylet within the OG tube is maneuvered to displace the esophagus away from the adjacent left atrium when radiofrequency ablation (RFA) is being administered.
The tool, marketed under the brand name EsoSure, was first made available almost 2 years ago, but the recently completed multicenter observational study was conducted to provide a more systematic evaluation of its safety and efficacy in routine use. In this study, 101 consecutive patients scheduled for RFA for AF had their esophagus displaced by the stylet during the procedure. The temperature of the esophagus as well as any adverse events involving the upper gastrointestinal tract were evaluated during the procedure. Patients were then followed for at least 6 months.
“The principal finding of our study is that mechanical displacement of the esophagus with the help of the EsoSure device is safe and provides sufficient room to deliver the intended energy at the site of ablation without any rise in temperature over 38° C,” Dr. Parikh reported.
The mean age of the 101 patients who participated in this study was 65 years. About half were female. The mean body mass index (BMI) was 32 kg/m2. The mean CHA2DS2-VASc score was 2.4. Barium x-rays were used to confirm esophageal displacement.
After the procedure, patients were discharged on a proton pump inhibitor and sucralfate, which inhibits pepsin activity and protects against ulceration. Follow-up endoscopy was performed only when medically indicated, but all patients were evaluated over the course of follow-up for odynophagia, dysphagia, hematemesis, dyspepsia, and other GI symptoms.
Pulmonary vein isolation (PVI) was achieved successfully in all cases. Although there was a rapid temperature rise at the site of ablation over the course of RFA, the esophagus was adequately displaced from the source of energy, as confirmed with the absence of significant temperature rises in this tissue. The mean esophageal displacement was 2.53 cm.
The only complication in this series, occurring in 7% of patients, was dysphagia. All cases of dysphagia developed immediately or soon after the procedure. All were mild, and all resolved within several days. There were no late GI complications observed, although Dr. Parikh acknowledged that no follow-up endoscopy was performed to rule out any esophageal injury.
In contrast, without the deviation permitted by the esophageal retractor, the rapid rise in temperature “could have precluded PVI,” Dr. Parikh maintained. He said that the retractor permitted the esophagus to be cleared from potential injury, as indicated by the lack of a temperature rise in esophageal tissue, in 100% of the cases. He noted that the tool is now in routine use at his center.
According to Dr. Lakkireddy, this tool is already in routine use at several centers across the country. The goal of this study was to provide an objective documentation of the ability of the device to enable successful posterior wall isolation during PVI without esophageal injury.
“It helped us get to the endpoint without a problem 100% of the time,” Dr. Lakkireddy reported.
Dr. Parikh has no industry relationships relevant to this study.
ORLANDO – A relatively simple mechanical tool to move the esophagus away from the energy delivered during ablation of atrial fibrillation (AF) does what it is supposed to do, according to data from a multicenter observational study presented at the AF Symposium 2017.
When esophageal temperature during the ablation procedure was monitored in 101 consecutive cases, no recording exceeded 38° C, according to Valay Parikh, MD, a clinical cardiac electrophysiology fellow working under Dhanunjaya Lakkireddy, MD, at the Kansas University Medical Center, Kansas City.
The tool is a stylet constructed from a nickel-titanium (nitinol) alloy. Malleable at room temperature, the stylet is inserted into an 18 Fr orogastric (OG) tube. Firmer at body temperature, the stylet within the OG tube is maneuvered to displace the esophagus away from the adjacent left atrium when radiofrequency ablation (RFA) is being administered.
The tool, marketed under the brand name EsoSure, was first made available almost 2 years ago, but the recently completed multicenter observational study was conducted to provide a more systematic evaluation of its safety and efficacy in routine use. In this study, 101 consecutive patients scheduled for RFA for AF had their esophagus displaced by the stylet during the procedure. The temperature of the esophagus as well as any adverse events involving the upper gastrointestinal tract were evaluated during the procedure. Patients were then followed for at least 6 months.
“The principal finding of our study is that mechanical displacement of the esophagus with the help of the EsoSure device is safe and provides sufficient room to deliver the intended energy at the site of ablation without any rise in temperature over 38° C,” Dr. Parikh reported.
The mean age of the 101 patients who participated in this study was 65 years. About half were female. The mean body mass index (BMI) was 32 kg/m2. The mean CHA2DS2-VASc score was 2.4. Barium x-rays were used to confirm esophageal displacement.
After the procedure, patients were discharged on a proton pump inhibitor and sucralfate, which inhibits pepsin activity and protects against ulceration. Follow-up endoscopy was performed only when medically indicated, but all patients were evaluated over the course of follow-up for odynophagia, dysphagia, hematemesis, dyspepsia, and other GI symptoms.
Pulmonary vein isolation (PVI) was achieved successfully in all cases. Although there was a rapid temperature rise at the site of ablation over the course of RFA, the esophagus was adequately displaced from the source of energy, as confirmed with the absence of significant temperature rises in this tissue. The mean esophageal displacement was 2.53 cm.
The only complication in this series, occurring in 7% of patients, was dysphagia. All cases of dysphagia developed immediately or soon after the procedure. All were mild, and all resolved within several days. There were no late GI complications observed, although Dr. Parikh acknowledged that no follow-up endoscopy was performed to rule out any esophageal injury.
In contrast, without the deviation permitted by the esophageal retractor, the rapid rise in temperature “could have precluded PVI,” Dr. Parikh maintained. He said that the retractor permitted the esophagus to be cleared from potential injury, as indicated by the lack of a temperature rise in esophageal tissue, in 100% of the cases. He noted that the tool is now in routine use at his center.
According to Dr. Lakkireddy, this tool is already in routine use at several centers across the country. The goal of this study was to provide an objective documentation of the ability of the device to enable successful posterior wall isolation during PVI without esophageal injury.
“It helped us get to the endpoint without a problem 100% of the time,” Dr. Lakkireddy reported.
Dr. Parikh has no industry relationships relevant to this study.
ORLANDO – A relatively simple mechanical tool to move the esophagus away from the energy delivered during ablation of atrial fibrillation (AF) does what it is supposed to do, according to data from a multicenter observational study presented at the AF Symposium 2017.
When esophageal temperature during the ablation procedure was monitored in 101 consecutive cases, no recording exceeded 38° C, according to Valay Parikh, MD, a clinical cardiac electrophysiology fellow working under Dhanunjaya Lakkireddy, MD, at the Kansas University Medical Center, Kansas City.
The tool is a stylet constructed from a nickel-titanium (nitinol) alloy. Malleable at room temperature, the stylet is inserted into an 18 Fr orogastric (OG) tube. Firmer at body temperature, the stylet within the OG tube is maneuvered to displace the esophagus away from the adjacent left atrium when radiofrequency ablation (RFA) is being administered.
The tool, marketed under the brand name EsoSure, was first made available almost 2 years ago, but the recently completed multicenter observational study was conducted to provide a more systematic evaluation of its safety and efficacy in routine use. In this study, 101 consecutive patients scheduled for RFA for AF had their esophagus displaced by the stylet during the procedure. The temperature of the esophagus as well as any adverse events involving the upper gastrointestinal tract were evaluated during the procedure. Patients were then followed for at least 6 months.
“The principal finding of our study is that mechanical displacement of the esophagus with the help of the EsoSure device is safe and provides sufficient room to deliver the intended energy at the site of ablation without any rise in temperature over 38° C,” Dr. Parikh reported.
The mean age of the 101 patients who participated in this study was 65 years. About half were female. The mean body mass index (BMI) was 32 kg/m2. The mean CHA2DS2-VASc score was 2.4. Barium x-rays were used to confirm esophageal displacement.
After the procedure, patients were discharged on a proton pump inhibitor and sucralfate, which inhibits pepsin activity and protects against ulceration. Follow-up endoscopy was performed only when medically indicated, but all patients were evaluated over the course of follow-up for odynophagia, dysphagia, hematemesis, dyspepsia, and other GI symptoms.
Pulmonary vein isolation (PVI) was achieved successfully in all cases. Although there was a rapid temperature rise at the site of ablation over the course of RFA, the esophagus was adequately displaced from the source of energy, as confirmed with the absence of significant temperature rises in this tissue. The mean esophageal displacement was 2.53 cm.
The only complication in this series, occurring in 7% of patients, was dysphagia. All cases of dysphagia developed immediately or soon after the procedure. All were mild, and all resolved within several days. There were no late GI complications observed, although Dr. Parikh acknowledged that no follow-up endoscopy was performed to rule out any esophageal injury.
In contrast, without the deviation permitted by the esophageal retractor, the rapid rise in temperature “could have precluded PVI,” Dr. Parikh maintained. He said that the retractor permitted the esophagus to be cleared from potential injury, as indicated by the lack of a temperature rise in esophageal tissue, in 100% of the cases. He noted that the tool is now in routine use at his center.
According to Dr. Lakkireddy, this tool is already in routine use at several centers across the country. The goal of this study was to provide an objective documentation of the ability of the device to enable successful posterior wall isolation during PVI without esophageal injury.
“It helped us get to the endpoint without a problem 100% of the time,” Dr. Lakkireddy reported.
Dr. Parikh has no industry relationships relevant to this study.
AT THE INTERNATIONAL AF SYMPOSIUM
Key clinical point: The efficacy of a tool to move the esophagus out of the way when performing ablation for atrial fibrillation is supported by a multicenter study.
Major finding: In 101 consecutive cases at four centers, all ablations were completed successfully with no esophageal temperature rise.
Data source: Prospective observational study.
Disclosures: Dr. Parikh has no industry relationships relevant to this study.
European guidelines strengthen screening for silent AF
ORLANDO – New European Society of Cardiology management guidelines encourage electrocardiogram screening for silent atrial fibrillation (AF) in high-risk patients, even if these guidelines do not fully spell out the specific definition of high risk, according to a guideline reviewer who summarized key points at the annual International AF Symposium.
“For the first time in any guideline, we now have a recommendation for systematic ECG screening of silent AF, particularly for patients older than age 75 years or those otherwise at high risk of stroke,” reported John Camm, MD, professor of clinical cardiology, St. George’s University, London.
Moreover, the screening for silent AF proposed in the most recent ESC guidelines for high-risk individuals is opportunistic rather than systematic, meaning that screening should be performed in patients who are interacting with the health system for another reason, such as an annual flu vaccination. This can be problematic for paroxysmal AF, which is the most common form. Dr. Camm, who was the first author of the 2010 ESC AF guidelines (Europace. 2010 Oct;12[10]:1360-420), acknowledged this issue.
“The problem is that AF must be present at the time that the ECG is performed and we know that AF is often intermittent. The longer or the more frequently ECG is used, the more paroxysmal AF will be detected, but of course this increases the cost of detection,” Dr. Camm noted. The guidelines note that the technology of detecting paroxysmal AF is evolving and may soon include portable smartphone technology but cautioned that these have yet to be formally evaluated. The potential value of daily short-term recordings in high-risk populations is raised but not endorsed in the new AF guidelines.
“One simple way to screen for AF is pulse palpation, which is something we all learned in medical school, but that is rarely undertaken these days,” Dr. Camm observed.
The value of pulse palpation, which can be readily taught to motivated patients, is that it has a very high negative predictive value, according to Dr. Camm. He suggested that absence of any pulse abnormalities essentially rules out the presence of atrial fibrillation even though abnormalities, if present, can be generated by rhythm disturbances other than AF. Screening ECGs in patients with pulse abnormalities are required to confirm the AF diagnosis.
The rising rates of AF in the United States, United Kingdom, and many other parts of the world are incompletely understood, but the ESC guidelines imply that the efforts to prevent the associated risk of stroke will require better detection of silent AF, which represents up to 40% of these rhythm disturbances. There is, as yet, no high-level evidence with which to confirm that early detection of silent AF leads to altered management that improves outcomes, according to Dr. Camm, but he suggested that this is a logical expectation that is currently being explored with ongoing studies.
Citing the potential for sensors and software built into watches and phones to facilitate screening for silent AF, Dr. Camm indicated that this is a field that may evolve quickly. In the meantime, he concurred with ESC guidelines, advocating screening for silent AF in older patients and patients with risk factors for stroke or AF.
Dr. Camm reports financial relationships with Bayer, Biotronik, Boehringer Ingelheim, Bristol-Myers Squibb, Boston Scientific, Daiichi, Eli Lilly, Laguna, Mitsubishi, Medtronic, Menarini, Novartis, Richmond Pharmacology, St. Jude Medical, and Servier.
ORLANDO – New European Society of Cardiology management guidelines encourage electrocardiogram screening for silent atrial fibrillation (AF) in high-risk patients, even if these guidelines do not fully spell out the specific definition of high risk, according to a guideline reviewer who summarized key points at the annual International AF Symposium.
“For the first time in any guideline, we now have a recommendation for systematic ECG screening of silent AF, particularly for patients older than age 75 years or those otherwise at high risk of stroke,” reported John Camm, MD, professor of clinical cardiology, St. George’s University, London.
Moreover, the screening for silent AF proposed in the most recent ESC guidelines for high-risk individuals is opportunistic rather than systematic, meaning that screening should be performed in patients who are interacting with the health system for another reason, such as an annual flu vaccination. This can be problematic for paroxysmal AF, which is the most common form. Dr. Camm, who was the first author of the 2010 ESC AF guidelines (Europace. 2010 Oct;12[10]:1360-420), acknowledged this issue.
“The problem is that AF must be present at the time that the ECG is performed and we know that AF is often intermittent. The longer or the more frequently ECG is used, the more paroxysmal AF will be detected, but of course this increases the cost of detection,” Dr. Camm noted. The guidelines note that the technology of detecting paroxysmal AF is evolving and may soon include portable smartphone technology but cautioned that these have yet to be formally evaluated. The potential value of daily short-term recordings in high-risk populations is raised but not endorsed in the new AF guidelines.
“One simple way to screen for AF is pulse palpation, which is something we all learned in medical school, but that is rarely undertaken these days,” Dr. Camm observed.
The value of pulse palpation, which can be readily taught to motivated patients, is that it has a very high negative predictive value, according to Dr. Camm. He suggested that absence of any pulse abnormalities essentially rules out the presence of atrial fibrillation even though abnormalities, if present, can be generated by rhythm disturbances other than AF. Screening ECGs in patients with pulse abnormalities are required to confirm the AF diagnosis.
The rising rates of AF in the United States, United Kingdom, and many other parts of the world are incompletely understood, but the ESC guidelines imply that the efforts to prevent the associated risk of stroke will require better detection of silent AF, which represents up to 40% of these rhythm disturbances. There is, as yet, no high-level evidence with which to confirm that early detection of silent AF leads to altered management that improves outcomes, according to Dr. Camm, but he suggested that this is a logical expectation that is currently being explored with ongoing studies.
Citing the potential for sensors and software built into watches and phones to facilitate screening for silent AF, Dr. Camm indicated that this is a field that may evolve quickly. In the meantime, he concurred with ESC guidelines, advocating screening for silent AF in older patients and patients with risk factors for stroke or AF.
Dr. Camm reports financial relationships with Bayer, Biotronik, Boehringer Ingelheim, Bristol-Myers Squibb, Boston Scientific, Daiichi, Eli Lilly, Laguna, Mitsubishi, Medtronic, Menarini, Novartis, Richmond Pharmacology, St. Jude Medical, and Servier.
ORLANDO – New European Society of Cardiology management guidelines encourage electrocardiogram screening for silent atrial fibrillation (AF) in high-risk patients, even if these guidelines do not fully spell out the specific definition of high risk, according to a guideline reviewer who summarized key points at the annual International AF Symposium.
“For the first time in any guideline, we now have a recommendation for systematic ECG screening of silent AF, particularly for patients older than age 75 years or those otherwise at high risk of stroke,” reported John Camm, MD, professor of clinical cardiology, St. George’s University, London.
Moreover, the screening for silent AF proposed in the most recent ESC guidelines for high-risk individuals is opportunistic rather than systematic, meaning that screening should be performed in patients who are interacting with the health system for another reason, such as an annual flu vaccination. This can be problematic for paroxysmal AF, which is the most common form. Dr. Camm, who was the first author of the 2010 ESC AF guidelines (Europace. 2010 Oct;12[10]:1360-420), acknowledged this issue.
“The problem is that AF must be present at the time that the ECG is performed and we know that AF is often intermittent. The longer or the more frequently ECG is used, the more paroxysmal AF will be detected, but of course this increases the cost of detection,” Dr. Camm noted. The guidelines note that the technology of detecting paroxysmal AF is evolving and may soon include portable smartphone technology but cautioned that these have yet to be formally evaluated. The potential value of daily short-term recordings in high-risk populations is raised but not endorsed in the new AF guidelines.
“One simple way to screen for AF is pulse palpation, which is something we all learned in medical school, but that is rarely undertaken these days,” Dr. Camm observed.
The value of pulse palpation, which can be readily taught to motivated patients, is that it has a very high negative predictive value, according to Dr. Camm. He suggested that absence of any pulse abnormalities essentially rules out the presence of atrial fibrillation even though abnormalities, if present, can be generated by rhythm disturbances other than AF. Screening ECGs in patients with pulse abnormalities are required to confirm the AF diagnosis.
The rising rates of AF in the United States, United Kingdom, and many other parts of the world are incompletely understood, but the ESC guidelines imply that the efforts to prevent the associated risk of stroke will require better detection of silent AF, which represents up to 40% of these rhythm disturbances. There is, as yet, no high-level evidence with which to confirm that early detection of silent AF leads to altered management that improves outcomes, according to Dr. Camm, but he suggested that this is a logical expectation that is currently being explored with ongoing studies.
Citing the potential for sensors and software built into watches and phones to facilitate screening for silent AF, Dr. Camm indicated that this is a field that may evolve quickly. In the meantime, he concurred with ESC guidelines, advocating screening for silent AF in older patients and patients with risk factors for stroke or AF.
Dr. Camm reports financial relationships with Bayer, Biotronik, Boehringer Ingelheim, Bristol-Myers Squibb, Boston Scientific, Daiichi, Eli Lilly, Laguna, Mitsubishi, Medtronic, Menarini, Novartis, Richmond Pharmacology, St. Jude Medical, and Servier.
Positive experience reported for new AF ablation system
ORLANDO – A uniquely designed multielectrode radiofrequency ablation (RFA) balloon catheter system for the treatment of atrial fibrillation (AF) performed well in a first-in-man study.
The new ablation system is designed to provide the flexibility of conventional RFA devices in treating a broad array of AF triggers with the type of predictable energy delivery more closely associated with cryoballoon ablation, according to the principal investigator, Matthew G. Daly, MB, ChB, a cardiologist at Christchurch (New Zealand) Hospital.
The inflatable experimental device features 18 electrodes, a built-in camera, integrated mapping and pacing, and irrigation designed to reduce the risk of clot formation. On contact, the 12 electrodes situated on the equator of the spherical device, along with the six electrodes situated on the polar ends, are initially employed to select the ablation pattern. RFA can be delivered immediately through the same electrodes once proper contact is established using the built-in cameras for real-time visualization.
No significant adverse events were encountered during the procedure or over the course of follow-up, according to Dr. Daly. PV isolation was achieved in 65 of 68 (96%) of veins treated. The average number of ablations required per PV isolation was 3.1. On average, it took 12 minutes to isolate all veins per patient, according to Dr. Daly, who characterized this as “respectable,” given that this was a novel technology being performed in a clinical study for the first time. The average balloon time was 1 hour 39 minutes.
For the patients followed through 6 months, 80% remain free of AF and off all medications.
“The system allowed for quick ablation without excessive catheter manipulations,” said Dr. Daly, suggesting that the performance was consistent with the theoretical advantages of a multipoint, single-shot design. Overall, Dr. Daly suggested that this device appears to permit RFA to be delivered in a manner that has been more closely related to the efficiency of cryoballoon ablation.
“The disadvantage, or perhaps the advantage, is that this is a device that requires a knowledge of electrophysiology,” said Dr. Daly, who said that physicians need to be familiar with isolating pulmonary veins in order to deliver the energy appropriately.
One of the theoretical advantages of this device over conventional RFA ablation is that it will provide more consistent power and temperature as long as appropriate contact is achieved. He noted that the variability in energy delivery according to angle or contact force has been one of the weaknesses of conventional RFA devices.
“Contact is king. This has always been true, but with this device the manufacturer recommended that we only applied energy when we thought contact was perfect,” Dr. Daly said. He acknowledged that he deviated from this recommendation in some instances, “but it turns out that if you have good contact, you get signal elimination almost immediately or at least within a few seconds,” but less dependable results when contact is compromised, such as in those instances where blood is an obstacle.
Because of its ability to deliver energy in a single shot at multiple points, this device has the potential to permit successful ablation with a shorter procedure time than with conventional RFA. Dr. Daly said this device is “light on its feet” and required relatively little time to maneuver into place. However, he said that procedure times in this initial study were longer because of inexperience and the need for “checking and rechecking” settings and positions.
Dr. Daly reported no industry relationships relevant to this study.
ORLANDO – A uniquely designed multielectrode radiofrequency ablation (RFA) balloon catheter system for the treatment of atrial fibrillation (AF) performed well in a first-in-man study.
The new ablation system is designed to provide the flexibility of conventional RFA devices in treating a broad array of AF triggers with the type of predictable energy delivery more closely associated with cryoballoon ablation, according to the principal investigator, Matthew G. Daly, MB, ChB, a cardiologist at Christchurch (New Zealand) Hospital.
The inflatable experimental device features 18 electrodes, a built-in camera, integrated mapping and pacing, and irrigation designed to reduce the risk of clot formation. On contact, the 12 electrodes situated on the equator of the spherical device, along with the six electrodes situated on the polar ends, are initially employed to select the ablation pattern. RFA can be delivered immediately through the same electrodes once proper contact is established using the built-in cameras for real-time visualization.
No significant adverse events were encountered during the procedure or over the course of follow-up, according to Dr. Daly. PV isolation was achieved in 65 of 68 (96%) of veins treated. The average number of ablations required per PV isolation was 3.1. On average, it took 12 minutes to isolate all veins per patient, according to Dr. Daly, who characterized this as “respectable,” given that this was a novel technology being performed in a clinical study for the first time. The average balloon time was 1 hour 39 minutes.
For the patients followed through 6 months, 80% remain free of AF and off all medications.
“The system allowed for quick ablation without excessive catheter manipulations,” said Dr. Daly, suggesting that the performance was consistent with the theoretical advantages of a multipoint, single-shot design. Overall, Dr. Daly suggested that this device appears to permit RFA to be delivered in a manner that has been more closely related to the efficiency of cryoballoon ablation.
“The disadvantage, or perhaps the advantage, is that this is a device that requires a knowledge of electrophysiology,” said Dr. Daly, who said that physicians need to be familiar with isolating pulmonary veins in order to deliver the energy appropriately.
One of the theoretical advantages of this device over conventional RFA ablation is that it will provide more consistent power and temperature as long as appropriate contact is achieved. He noted that the variability in energy delivery according to angle or contact force has been one of the weaknesses of conventional RFA devices.
“Contact is king. This has always been true, but with this device the manufacturer recommended that we only applied energy when we thought contact was perfect,” Dr. Daly said. He acknowledged that he deviated from this recommendation in some instances, “but it turns out that if you have good contact, you get signal elimination almost immediately or at least within a few seconds,” but less dependable results when contact is compromised, such as in those instances where blood is an obstacle.
Because of its ability to deliver energy in a single shot at multiple points, this device has the potential to permit successful ablation with a shorter procedure time than with conventional RFA. Dr. Daly said this device is “light on its feet” and required relatively little time to maneuver into place. However, he said that procedure times in this initial study were longer because of inexperience and the need for “checking and rechecking” settings and positions.
Dr. Daly reported no industry relationships relevant to this study.
ORLANDO – A uniquely designed multielectrode radiofrequency ablation (RFA) balloon catheter system for the treatment of atrial fibrillation (AF) performed well in a first-in-man study.
The new ablation system is designed to provide the flexibility of conventional RFA devices in treating a broad array of AF triggers with the type of predictable energy delivery more closely associated with cryoballoon ablation, according to the principal investigator, Matthew G. Daly, MB, ChB, a cardiologist at Christchurch (New Zealand) Hospital.
The inflatable experimental device features 18 electrodes, a built-in camera, integrated mapping and pacing, and irrigation designed to reduce the risk of clot formation. On contact, the 12 electrodes situated on the equator of the spherical device, along with the six electrodes situated on the polar ends, are initially employed to select the ablation pattern. RFA can be delivered immediately through the same electrodes once proper contact is established using the built-in cameras for real-time visualization.
No significant adverse events were encountered during the procedure or over the course of follow-up, according to Dr. Daly. PV isolation was achieved in 65 of 68 (96%) of veins treated. The average number of ablations required per PV isolation was 3.1. On average, it took 12 minutes to isolate all veins per patient, according to Dr. Daly, who characterized this as “respectable,” given that this was a novel technology being performed in a clinical study for the first time. The average balloon time was 1 hour 39 minutes.
For the patients followed through 6 months, 80% remain free of AF and off all medications.
“The system allowed for quick ablation without excessive catheter manipulations,” said Dr. Daly, suggesting that the performance was consistent with the theoretical advantages of a multipoint, single-shot design. Overall, Dr. Daly suggested that this device appears to permit RFA to be delivered in a manner that has been more closely related to the efficiency of cryoballoon ablation.
“The disadvantage, or perhaps the advantage, is that this is a device that requires a knowledge of electrophysiology,” said Dr. Daly, who said that physicians need to be familiar with isolating pulmonary veins in order to deliver the energy appropriately.
One of the theoretical advantages of this device over conventional RFA ablation is that it will provide more consistent power and temperature as long as appropriate contact is achieved. He noted that the variability in energy delivery according to angle or contact force has been one of the weaknesses of conventional RFA devices.
“Contact is king. This has always been true, but with this device the manufacturer recommended that we only applied energy when we thought contact was perfect,” Dr. Daly said. He acknowledged that he deviated from this recommendation in some instances, “but it turns out that if you have good contact, you get signal elimination almost immediately or at least within a few seconds,” but less dependable results when contact is compromised, such as in those instances where blood is an obstacle.
Because of its ability to deliver energy in a single shot at multiple points, this device has the potential to permit successful ablation with a shorter procedure time than with conventional RFA. Dr. Daly said this device is “light on its feet” and required relatively little time to maneuver into place. However, he said that procedure times in this initial study were longer because of inexperience and the need for “checking and rechecking” settings and positions.
Dr. Daly reported no industry relationships relevant to this study.
AT AF SYMPOSIUM 2017
Key clinical point: A novel ablation catheter system for atrial fibrillation appears to minimize the disadvantages of existing strategies in initial study.
Major finding: A first-in-man study documents safety with 98% technical success rate.
Data source: A prospective, multicenter study.
Disclosures: Dr. Daly reported no industry relationships relevant to this study.
Stroke rates high when catheter ablation of AF fails
ORLANDO – In patients with atrial fibrillation (AF) who fail to achieve rhythm control after catheter ablation, the risk of ischemic stroke may approach 30% over 5 or more years of follow-up, despite optimized anticoagulation therapy, according to data from 1,002 consecutive patients presented at the annual International AF Symposium.
“The risk of stroke is high among patients after unsuccessful catheter ablation,” confirmed Mihran Martirosyan, MD, Erasmus Medical Center, Rotterdam, the Netherlands. He asserted that this is the first study to investigate long-term clinical outcomes of AF patients with unsuccessful rhythm control following repeated catheter ablation.
The retrospective analysis was conducted in 1,002 patients who underwent catheter ablation after failing pharmacologic treatment of AF. Of these, 169 (17%) failed the ablation, but the focus of this study was on the subgroup of 67 catheter ablation treatment failures that have been followed for at least 5 years. All had been maintained on anticoagulation therapy.
Within this group, 18 (27%) had an ischemic stroke over the course of follow-up. The average time to stroke after the first ablation procedure was 3.9 years.
Prior to being declared catheter ablation failures, the average number of ablation procedures in this long-term follow-up group was 1.7. In 55.2% of patients, the first ablation was performed with a cryoballoon. The remaining first ablations were delivered with radiofrequency. For a second or third ablation, the same techniques were commonly repeated, but 25% received a cavotricuspid isthmus ablation, and 12% underwent a VATS-Maze procedure.
There were no deaths in this series, in which the average patient age was 66 years. The average duration of AF was 12 years, the mean left atrial size was 45 mm, and the average left ventricular ejection fraction was 55%.
In this study, catheter ablation failure was defined as inability to regain rhythm control despite repeated ablation procedures. However, many patients who initially achieve rhythm control after catheter ablation have recurrence of AF over time. It is unclear whether patients who initially achieve but then lose rhythm control face the same high risk for stroke as seen in the Dutch series if followed long-term.
One study suggests that they may not. In 631 consecutive patients who underwent a mean 1.5 catheter ablations before achieving rhythm control, 34% had an AF recurrence at 1 year (Europace 2014 Oct 21;17[3]:403-8). When followed for a mean 4.1 years of additional follow-up (5.1 years from the initial ablation), only 10% had a serious adverse event, such as heart failure or hemorrhage, and only 2% had a cerebrovascular event.
Numerous clinical studies have shown that catheter ablation is more effective than pharmacologic therapy for both regaining rhythm control in AF patients and reducing symptoms, according to Dr. Martirosyan, but these long-term follow-up data confirm that the risk of thromboembolic complications remains high in those who fail the initial catheter ablation. Of the 18 strokes, only 4 occurred in the first year of follow-up. The remaining strokes accrued slowly over time. Strokes were recorded up until 10 years after the ablation, the longest period that any patient was followed.
Dr. Martirosyan reports no relevant financial relationships.
ORLANDO – In patients with atrial fibrillation (AF) who fail to achieve rhythm control after catheter ablation, the risk of ischemic stroke may approach 30% over 5 or more years of follow-up, despite optimized anticoagulation therapy, according to data from 1,002 consecutive patients presented at the annual International AF Symposium.
“The risk of stroke is high among patients after unsuccessful catheter ablation,” confirmed Mihran Martirosyan, MD, Erasmus Medical Center, Rotterdam, the Netherlands. He asserted that this is the first study to investigate long-term clinical outcomes of AF patients with unsuccessful rhythm control following repeated catheter ablation.
The retrospective analysis was conducted in 1,002 patients who underwent catheter ablation after failing pharmacologic treatment of AF. Of these, 169 (17%) failed the ablation, but the focus of this study was on the subgroup of 67 catheter ablation treatment failures that have been followed for at least 5 years. All had been maintained on anticoagulation therapy.
Within this group, 18 (27%) had an ischemic stroke over the course of follow-up. The average time to stroke after the first ablation procedure was 3.9 years.
Prior to being declared catheter ablation failures, the average number of ablation procedures in this long-term follow-up group was 1.7. In 55.2% of patients, the first ablation was performed with a cryoballoon. The remaining first ablations were delivered with radiofrequency. For a second or third ablation, the same techniques were commonly repeated, but 25% received a cavotricuspid isthmus ablation, and 12% underwent a VATS-Maze procedure.
There were no deaths in this series, in which the average patient age was 66 years. The average duration of AF was 12 years, the mean left atrial size was 45 mm, and the average left ventricular ejection fraction was 55%.
In this study, catheter ablation failure was defined as inability to regain rhythm control despite repeated ablation procedures. However, many patients who initially achieve rhythm control after catheter ablation have recurrence of AF over time. It is unclear whether patients who initially achieve but then lose rhythm control face the same high risk for stroke as seen in the Dutch series if followed long-term.
One study suggests that they may not. In 631 consecutive patients who underwent a mean 1.5 catheter ablations before achieving rhythm control, 34% had an AF recurrence at 1 year (Europace 2014 Oct 21;17[3]:403-8). When followed for a mean 4.1 years of additional follow-up (5.1 years from the initial ablation), only 10% had a serious adverse event, such as heart failure or hemorrhage, and only 2% had a cerebrovascular event.
Numerous clinical studies have shown that catheter ablation is more effective than pharmacologic therapy for both regaining rhythm control in AF patients and reducing symptoms, according to Dr. Martirosyan, but these long-term follow-up data confirm that the risk of thromboembolic complications remains high in those who fail the initial catheter ablation. Of the 18 strokes, only 4 occurred in the first year of follow-up. The remaining strokes accrued slowly over time. Strokes were recorded up until 10 years after the ablation, the longest period that any patient was followed.
Dr. Martirosyan reports no relevant financial relationships.
ORLANDO – In patients with atrial fibrillation (AF) who fail to achieve rhythm control after catheter ablation, the risk of ischemic stroke may approach 30% over 5 or more years of follow-up, despite optimized anticoagulation therapy, according to data from 1,002 consecutive patients presented at the annual International AF Symposium.
“The risk of stroke is high among patients after unsuccessful catheter ablation,” confirmed Mihran Martirosyan, MD, Erasmus Medical Center, Rotterdam, the Netherlands. He asserted that this is the first study to investigate long-term clinical outcomes of AF patients with unsuccessful rhythm control following repeated catheter ablation.
The retrospective analysis was conducted in 1,002 patients who underwent catheter ablation after failing pharmacologic treatment of AF. Of these, 169 (17%) failed the ablation, but the focus of this study was on the subgroup of 67 catheter ablation treatment failures that have been followed for at least 5 years. All had been maintained on anticoagulation therapy.
Within this group, 18 (27%) had an ischemic stroke over the course of follow-up. The average time to stroke after the first ablation procedure was 3.9 years.
Prior to being declared catheter ablation failures, the average number of ablation procedures in this long-term follow-up group was 1.7. In 55.2% of patients, the first ablation was performed with a cryoballoon. The remaining first ablations were delivered with radiofrequency. For a second or third ablation, the same techniques were commonly repeated, but 25% received a cavotricuspid isthmus ablation, and 12% underwent a VATS-Maze procedure.
There were no deaths in this series, in which the average patient age was 66 years. The average duration of AF was 12 years, the mean left atrial size was 45 mm, and the average left ventricular ejection fraction was 55%.
In this study, catheter ablation failure was defined as inability to regain rhythm control despite repeated ablation procedures. However, many patients who initially achieve rhythm control after catheter ablation have recurrence of AF over time. It is unclear whether patients who initially achieve but then lose rhythm control face the same high risk for stroke as seen in the Dutch series if followed long-term.
One study suggests that they may not. In 631 consecutive patients who underwent a mean 1.5 catheter ablations before achieving rhythm control, 34% had an AF recurrence at 1 year (Europace 2014 Oct 21;17[3]:403-8). When followed for a mean 4.1 years of additional follow-up (5.1 years from the initial ablation), only 10% had a serious adverse event, such as heart failure or hemorrhage, and only 2% had a cerebrovascular event.
Numerous clinical studies have shown that catheter ablation is more effective than pharmacologic therapy for both regaining rhythm control in AF patients and reducing symptoms, according to Dr. Martirosyan, but these long-term follow-up data confirm that the risk of thromboembolic complications remains high in those who fail the initial catheter ablation. Of the 18 strokes, only 4 occurred in the first year of follow-up. The remaining strokes accrued slowly over time. Strokes were recorded up until 10 years after the ablation, the longest period that any patient was followed.
Dr. Martirosyan reports no relevant financial relationships.
AT THE AF SYMPOSIUM 2017
Key clinical point: If catheter ablation of atrial fibrillation fails, stroke rates are high despite optimized anticoagulation therapy.
Major finding: In a median follow-up of up to 5 years after ablation, 27% of patients had an ischemic stroke.
Data source: Retrospective analysis.
Disclosures: Dr. Martirosyan reports no relevant financial relationships.
As-needed anticoagulation for intermittent Afib raises concerns
ORLANDO – A pilot study that suggested as-needed anticoagulation could be effective in preventing stroke in at least some patients after successful ablation of atrial fibrillation (AF) was received with caution at the annual International AF Symposium.
The positive findings, originally reported at the 2016 annual meeting of the Heart Rhythm Society (HRS), were updated at AF Symposium 2017 by Francis Marchlinski, MD, director of cardiac electrophysiology at the University of Pennsylvania. When delivering the data, he provided several caveats before other AF experts added their own.
The study was conducted in response to the substantial number of patients who request discontinuing anticoagulation therapy after a successful ablation for atrial fibrillation, according to Dr. Marchlinski. Current guidelines recommend anticoagulation in AF patients following ablation if they have risk factors for stroke even if their AF is controlled. However, according to Dr. Marchlinski, who cited five observational studies, the risk of stroke in patients with a negative electrocardiogram after ablation appears to be “in the neighborhood of 0.1%.”
“There are no randomized prospective trials that have assessed the safety of stopping anticoagulants, but the fact is that this is a pretty low event rate if the observational studies are accurate, and even if they are off by severalfold, it is likely that we would be unable to show the benefit of continuing anticoagulants in these patients,” Dr. Marchlinski observed.
A strategy of as-needed anticoagulants has been made practical by the introduction of novel oral anticoagulants (NOACs), which have a rapid onset of action relative to warfarin and would, therefore, be expected to provide rapid protection against AF-related stroke risk if initiated upon AF onset, according to Dr. Marchlinski. To test this approach, 105 “highly motivated” AF patients were selected for the pilot study.
In addition to 3 weeks of ECG monitoring to confirm the absence of AF, patients participating in the trial were required to demonstrate skill in pulse assessment, which they agreed to perform on a twice-daily basis. Use of a smartphone app that can detect AF was encouraged but not required. All patients were required to fill a prescription for a NOAC and told to initiate therapy for any AF episode of more than 1 hour.
Of the 105 patients, four were noncompliant with AF monitoring and removed from the study. Another two patients voluntarily requested to return to daily NOAC treatment. The remaining 99 were followed for 30 months. Of these, 18 had multiple episodes of AF and were transitioned back to daily NOAC therapy, 15 used NOAC on an as-needed basis at least once but remained off daily therapy, and the remaining 66 did not have an episode of AF that triggered a course of NOAC therapy.
In 263 patient years of follow-up, there was a single cerebrovascular accident (CVA). This occurred in an 81-year-old patient with a history of hypertrophic cardiomyopathy and an atherosclerotic aortic arch on imaging. The patient presented with neurologic symptoms but had a negative ECG. The CVA symptoms resolved with treatment.
In presenting these data, Dr. Marchlinski said, “PRN use of NOACs may be safe and effective to maintain a low risk of stroke when patients are adherent to diligent pulse monitoring.” However, he reiterated that the study group consisted of “a select group of motivated patients,” and he emphasized the patients must be followed closely.
In a discussion that followed this presentation, several experts expressed the usual caution about drawing conclusions from a single uncontrolled study, but Elaine M. Hylek, MD, professor of medicine, Boston University, added additional reservations to the “pill in a pocket” strategy. In particular, she noted an imperfect correlation between onset of AF and stroke risk. “I think this makes us [reluctant] to stop oral anticoagulation,” she said.
According to Daniel Singer, MD, chief of epidemiology, Harvard School of Public Health, Boston, the available data suggest that “once the AF is gone, the risk of stroke recedes,” but he indicated that all the variables of risk may not be fully understood. He said more “hard data” are needed to endorse a wider application of on-demand anticoagulation in patients like those entered into this study.
The fact that patients without AF following ablation remain at substantial risk of AF recurrences, including asymptomatic episodes, is a liability of as-needed anticoagulation, conceded Dr. Marchlinski. However, these initial results provide promise for the substantial proportion of patients without AF after ablation that wish to avoid anticoagulants and are willing to consider risks and benefits.
Dr. Marchlinski reports financial relationships with Abbott, Biosense Webster, Biotronik, Boston Scientific, St. Jude Medical, and Medtronic.
ORLANDO – A pilot study that suggested as-needed anticoagulation could be effective in preventing stroke in at least some patients after successful ablation of atrial fibrillation (AF) was received with caution at the annual International AF Symposium.
The positive findings, originally reported at the 2016 annual meeting of the Heart Rhythm Society (HRS), were updated at AF Symposium 2017 by Francis Marchlinski, MD, director of cardiac electrophysiology at the University of Pennsylvania. When delivering the data, he provided several caveats before other AF experts added their own.
The study was conducted in response to the substantial number of patients who request discontinuing anticoagulation therapy after a successful ablation for atrial fibrillation, according to Dr. Marchlinski. Current guidelines recommend anticoagulation in AF patients following ablation if they have risk factors for stroke even if their AF is controlled. However, according to Dr. Marchlinski, who cited five observational studies, the risk of stroke in patients with a negative electrocardiogram after ablation appears to be “in the neighborhood of 0.1%.”
“There are no randomized prospective trials that have assessed the safety of stopping anticoagulants, but the fact is that this is a pretty low event rate if the observational studies are accurate, and even if they are off by severalfold, it is likely that we would be unable to show the benefit of continuing anticoagulants in these patients,” Dr. Marchlinski observed.
A strategy of as-needed anticoagulants has been made practical by the introduction of novel oral anticoagulants (NOACs), which have a rapid onset of action relative to warfarin and would, therefore, be expected to provide rapid protection against AF-related stroke risk if initiated upon AF onset, according to Dr. Marchlinski. To test this approach, 105 “highly motivated” AF patients were selected for the pilot study.
In addition to 3 weeks of ECG monitoring to confirm the absence of AF, patients participating in the trial were required to demonstrate skill in pulse assessment, which they agreed to perform on a twice-daily basis. Use of a smartphone app that can detect AF was encouraged but not required. All patients were required to fill a prescription for a NOAC and told to initiate therapy for any AF episode of more than 1 hour.
Of the 105 patients, four were noncompliant with AF monitoring and removed from the study. Another two patients voluntarily requested to return to daily NOAC treatment. The remaining 99 were followed for 30 months. Of these, 18 had multiple episodes of AF and were transitioned back to daily NOAC therapy, 15 used NOAC on an as-needed basis at least once but remained off daily therapy, and the remaining 66 did not have an episode of AF that triggered a course of NOAC therapy.
In 263 patient years of follow-up, there was a single cerebrovascular accident (CVA). This occurred in an 81-year-old patient with a history of hypertrophic cardiomyopathy and an atherosclerotic aortic arch on imaging. The patient presented with neurologic symptoms but had a negative ECG. The CVA symptoms resolved with treatment.
In presenting these data, Dr. Marchlinski said, “PRN use of NOACs may be safe and effective to maintain a low risk of stroke when patients are adherent to diligent pulse monitoring.” However, he reiterated that the study group consisted of “a select group of motivated patients,” and he emphasized the patients must be followed closely.
In a discussion that followed this presentation, several experts expressed the usual caution about drawing conclusions from a single uncontrolled study, but Elaine M. Hylek, MD, professor of medicine, Boston University, added additional reservations to the “pill in a pocket” strategy. In particular, she noted an imperfect correlation between onset of AF and stroke risk. “I think this makes us [reluctant] to stop oral anticoagulation,” she said.
According to Daniel Singer, MD, chief of epidemiology, Harvard School of Public Health, Boston, the available data suggest that “once the AF is gone, the risk of stroke recedes,” but he indicated that all the variables of risk may not be fully understood. He said more “hard data” are needed to endorse a wider application of on-demand anticoagulation in patients like those entered into this study.
The fact that patients without AF following ablation remain at substantial risk of AF recurrences, including asymptomatic episodes, is a liability of as-needed anticoagulation, conceded Dr. Marchlinski. However, these initial results provide promise for the substantial proportion of patients without AF after ablation that wish to avoid anticoagulants and are willing to consider risks and benefits.
Dr. Marchlinski reports financial relationships with Abbott, Biosense Webster, Biotronik, Boston Scientific, St. Jude Medical, and Medtronic.
ORLANDO – A pilot study that suggested as-needed anticoagulation could be effective in preventing stroke in at least some patients after successful ablation of atrial fibrillation (AF) was received with caution at the annual International AF Symposium.
The positive findings, originally reported at the 2016 annual meeting of the Heart Rhythm Society (HRS), were updated at AF Symposium 2017 by Francis Marchlinski, MD, director of cardiac electrophysiology at the University of Pennsylvania. When delivering the data, he provided several caveats before other AF experts added their own.
The study was conducted in response to the substantial number of patients who request discontinuing anticoagulation therapy after a successful ablation for atrial fibrillation, according to Dr. Marchlinski. Current guidelines recommend anticoagulation in AF patients following ablation if they have risk factors for stroke even if their AF is controlled. However, according to Dr. Marchlinski, who cited five observational studies, the risk of stroke in patients with a negative electrocardiogram after ablation appears to be “in the neighborhood of 0.1%.”
“There are no randomized prospective trials that have assessed the safety of stopping anticoagulants, but the fact is that this is a pretty low event rate if the observational studies are accurate, and even if they are off by severalfold, it is likely that we would be unable to show the benefit of continuing anticoagulants in these patients,” Dr. Marchlinski observed.
A strategy of as-needed anticoagulants has been made practical by the introduction of novel oral anticoagulants (NOACs), which have a rapid onset of action relative to warfarin and would, therefore, be expected to provide rapid protection against AF-related stroke risk if initiated upon AF onset, according to Dr. Marchlinski. To test this approach, 105 “highly motivated” AF patients were selected for the pilot study.
In addition to 3 weeks of ECG monitoring to confirm the absence of AF, patients participating in the trial were required to demonstrate skill in pulse assessment, which they agreed to perform on a twice-daily basis. Use of a smartphone app that can detect AF was encouraged but not required. All patients were required to fill a prescription for a NOAC and told to initiate therapy for any AF episode of more than 1 hour.
Of the 105 patients, four were noncompliant with AF monitoring and removed from the study. Another two patients voluntarily requested to return to daily NOAC treatment. The remaining 99 were followed for 30 months. Of these, 18 had multiple episodes of AF and were transitioned back to daily NOAC therapy, 15 used NOAC on an as-needed basis at least once but remained off daily therapy, and the remaining 66 did not have an episode of AF that triggered a course of NOAC therapy.
In 263 patient years of follow-up, there was a single cerebrovascular accident (CVA). This occurred in an 81-year-old patient with a history of hypertrophic cardiomyopathy and an atherosclerotic aortic arch on imaging. The patient presented with neurologic symptoms but had a negative ECG. The CVA symptoms resolved with treatment.
In presenting these data, Dr. Marchlinski said, “PRN use of NOACs may be safe and effective to maintain a low risk of stroke when patients are adherent to diligent pulse monitoring.” However, he reiterated that the study group consisted of “a select group of motivated patients,” and he emphasized the patients must be followed closely.
In a discussion that followed this presentation, several experts expressed the usual caution about drawing conclusions from a single uncontrolled study, but Elaine M. Hylek, MD, professor of medicine, Boston University, added additional reservations to the “pill in a pocket” strategy. In particular, she noted an imperfect correlation between onset of AF and stroke risk. “I think this makes us [reluctant] to stop oral anticoagulation,” she said.
According to Daniel Singer, MD, chief of epidemiology, Harvard School of Public Health, Boston, the available data suggest that “once the AF is gone, the risk of stroke recedes,” but he indicated that all the variables of risk may not be fully understood. He said more “hard data” are needed to endorse a wider application of on-demand anticoagulation in patients like those entered into this study.
The fact that patients without AF following ablation remain at substantial risk of AF recurrences, including asymptomatic episodes, is a liability of as-needed anticoagulation, conceded Dr. Marchlinski. However, these initial results provide promise for the substantial proportion of patients without AF after ablation that wish to avoid anticoagulants and are willing to consider risks and benefits.
Dr. Marchlinski reports financial relationships with Abbott, Biosense Webster, Biotronik, Boston Scientific, St. Jude Medical, and Medtronic.
Key clinical point: Despite a positive pilot study, the efficacy of intermittent anticoagulation for stroke prevention after ablation for atrial fibrillation will be difficult to validate in a definitive fashion.
Major finding: Sixty-six percent of atrial fibrillation patients entirely avoided anticoagulation over 30 months of follow-up, but there are at least theoretical concerns.
Data source: A prospective, nonrandomized study.
Disclosures: Dr. Marchlinski reported financial relationships with Abbott, Biosense Webster, Biotronik, Boston Scientific, St. Jude Medical, and Medtronic.
Even small weight loss can improve long-term atrial fib ablation success
ORLANDO – Excess body weight exerts a major negative impact on the likelihood of remaining free of atrial fibrillation long term after an ablation procedure, according to a new set of data and a review of published studies.
“Just losing 3 pounds can dramatically improve the long-term success of an ablation when compared to a weight gain,” reported John D. Day, MD, medical director, Intermountain Heart Rhythm Specialists, Salt Lake City, at the annual International AF Symposium.
“As BMI goes up, long-term success in controlling AF goes down. The difference at 1 year may not be a big deal, but if you follow patients for a long time, weight control is a very big deal,” Dr. Day advised. He emphasized repeatedly, “We are just talking about a few pounds” for a favorable effect.
New data presented at the meeting supported the message. In the study, ablation outcomes in relationship to body mass index (BMI) were evaluated in 2,715 AF patients undergoing 3,742 ablations. Patients were stratified into five groups by BMI: less than 25 kg/m2, 25 to less than 30; 30 to less than 35; 35 to less than 40, and at least 40.
As BMI increased from less than 25 to at least 40, there were significant increases in left atrial size (P less than .005), CHADS2 scores (P = .002), persistent AF (P less than .0001), and longstanding AF (P less than .0001). Unlike persistent and long-term AF, rates of paroxysmal AF fell (48% to 16.3%; P less than .0001).
Not surprisingly and consistent with other published reports, increasing BMI was associated with increases in many of the key risk factors for AF in the study.
Specifically, as BMI increased from less than 25 to at least 40, the proportion of patients with cardiomyopathy climbed from 7.6% to 12.4% (P less than .001), hypertension climbed from 41% to 72.9% (P less than .0001), diabetes climbed from 4.3% to 23.3% (P less than .0001), and sleep apnea climbed from 7.0% to 46.9% (P less than .0001).
Dr. Day cited the LEGACY trial as one of the most influential studies associating weight loss with a reduction in AF burden (J Am Coll Cardiol. 2015 May 26;65[20]:2159-69). In that study, weight loss of at least 10% resulted in a sixfold increased likelihood of AF-free survival. Independent of AF, Dr. Day also pointed out that the sense of well-being among patients who achieved weight loss improved 200%.
Recognizing that major weight loss is difficult to achieve, Dr. Day repeatedly returned to the theme of weight control.
He cited one study in which AF patients were randomized to a weight loss program or usual care. In the usual care group, which included physician advice to lose weight, there was a small but significant weight loss. Even though the effect of that weight loss on AF burden was a fraction of that achieved in the group that achieved greater reductions in weight on active management, it, too, was significant, according to Dr. Day.
“Even brief physician advice can have a meaningful influence on waist circumference,” said Dr. Day, who urged physicians to inform their AF patients about the benefits of weight loss. Failing to do so might deprive patients of achieving the very modest reductions in weight loss required to improve their likelihood of freedom from AF, he added.
Dr. Winkle had no relevant financial relationships. Dr. Day reported a financial relationship with St. Jude Medical.
ORLANDO – Excess body weight exerts a major negative impact on the likelihood of remaining free of atrial fibrillation long term after an ablation procedure, according to a new set of data and a review of published studies.
“Just losing 3 pounds can dramatically improve the long-term success of an ablation when compared to a weight gain,” reported John D. Day, MD, medical director, Intermountain Heart Rhythm Specialists, Salt Lake City, at the annual International AF Symposium.
“As BMI goes up, long-term success in controlling AF goes down. The difference at 1 year may not be a big deal, but if you follow patients for a long time, weight control is a very big deal,” Dr. Day advised. He emphasized repeatedly, “We are just talking about a few pounds” for a favorable effect.
New data presented at the meeting supported the message. In the study, ablation outcomes in relationship to body mass index (BMI) were evaluated in 2,715 AF patients undergoing 3,742 ablations. Patients were stratified into five groups by BMI: less than 25 kg/m2, 25 to less than 30; 30 to less than 35; 35 to less than 40, and at least 40.
As BMI increased from less than 25 to at least 40, there were significant increases in left atrial size (P less than .005), CHADS2 scores (P = .002), persistent AF (P less than .0001), and longstanding AF (P less than .0001). Unlike persistent and long-term AF, rates of paroxysmal AF fell (48% to 16.3%; P less than .0001).
Not surprisingly and consistent with other published reports, increasing BMI was associated with increases in many of the key risk factors for AF in the study.
Specifically, as BMI increased from less than 25 to at least 40, the proportion of patients with cardiomyopathy climbed from 7.6% to 12.4% (P less than .001), hypertension climbed from 41% to 72.9% (P less than .0001), diabetes climbed from 4.3% to 23.3% (P less than .0001), and sleep apnea climbed from 7.0% to 46.9% (P less than .0001).
Dr. Day cited the LEGACY trial as one of the most influential studies associating weight loss with a reduction in AF burden (J Am Coll Cardiol. 2015 May 26;65[20]:2159-69). In that study, weight loss of at least 10% resulted in a sixfold increased likelihood of AF-free survival. Independent of AF, Dr. Day also pointed out that the sense of well-being among patients who achieved weight loss improved 200%.
Recognizing that major weight loss is difficult to achieve, Dr. Day repeatedly returned to the theme of weight control.
He cited one study in which AF patients were randomized to a weight loss program or usual care. In the usual care group, which included physician advice to lose weight, there was a small but significant weight loss. Even though the effect of that weight loss on AF burden was a fraction of that achieved in the group that achieved greater reductions in weight on active management, it, too, was significant, according to Dr. Day.
“Even brief physician advice can have a meaningful influence on waist circumference,” said Dr. Day, who urged physicians to inform their AF patients about the benefits of weight loss. Failing to do so might deprive patients of achieving the very modest reductions in weight loss required to improve their likelihood of freedom from AF, he added.
Dr. Winkle had no relevant financial relationships. Dr. Day reported a financial relationship with St. Jude Medical.
ORLANDO – Excess body weight exerts a major negative impact on the likelihood of remaining free of atrial fibrillation long term after an ablation procedure, according to a new set of data and a review of published studies.
“Just losing 3 pounds can dramatically improve the long-term success of an ablation when compared to a weight gain,” reported John D. Day, MD, medical director, Intermountain Heart Rhythm Specialists, Salt Lake City, at the annual International AF Symposium.
“As BMI goes up, long-term success in controlling AF goes down. The difference at 1 year may not be a big deal, but if you follow patients for a long time, weight control is a very big deal,” Dr. Day advised. He emphasized repeatedly, “We are just talking about a few pounds” for a favorable effect.
New data presented at the meeting supported the message. In the study, ablation outcomes in relationship to body mass index (BMI) were evaluated in 2,715 AF patients undergoing 3,742 ablations. Patients were stratified into five groups by BMI: less than 25 kg/m2, 25 to less than 30; 30 to less than 35; 35 to less than 40, and at least 40.
As BMI increased from less than 25 to at least 40, there were significant increases in left atrial size (P less than .005), CHADS2 scores (P = .002), persistent AF (P less than .0001), and longstanding AF (P less than .0001). Unlike persistent and long-term AF, rates of paroxysmal AF fell (48% to 16.3%; P less than .0001).
Not surprisingly and consistent with other published reports, increasing BMI was associated with increases in many of the key risk factors for AF in the study.
Specifically, as BMI increased from less than 25 to at least 40, the proportion of patients with cardiomyopathy climbed from 7.6% to 12.4% (P less than .001), hypertension climbed from 41% to 72.9% (P less than .0001), diabetes climbed from 4.3% to 23.3% (P less than .0001), and sleep apnea climbed from 7.0% to 46.9% (P less than .0001).
Dr. Day cited the LEGACY trial as one of the most influential studies associating weight loss with a reduction in AF burden (J Am Coll Cardiol. 2015 May 26;65[20]:2159-69). In that study, weight loss of at least 10% resulted in a sixfold increased likelihood of AF-free survival. Independent of AF, Dr. Day also pointed out that the sense of well-being among patients who achieved weight loss improved 200%.
Recognizing that major weight loss is difficult to achieve, Dr. Day repeatedly returned to the theme of weight control.
He cited one study in which AF patients were randomized to a weight loss program or usual care. In the usual care group, which included physician advice to lose weight, there was a small but significant weight loss. Even though the effect of that weight loss on AF burden was a fraction of that achieved in the group that achieved greater reductions in weight on active management, it, too, was significant, according to Dr. Day.
“Even brief physician advice can have a meaningful influence on waist circumference,” said Dr. Day, who urged physicians to inform their AF patients about the benefits of weight loss. Failing to do so might deprive patients of achieving the very modest reductions in weight loss required to improve their likelihood of freedom from AF, he added.
Dr. Winkle had no relevant financial relationships. Dr. Day reported a financial relationship with St. Jude Medical.
Key clinical point: New data expand evidence that obesity reduces long-term success of ablation for atrial fibrillation.
Major finding: Freedom from AF 5 years after ablation fell from 70% in patients with a BMI of less than 35 kg/m2 to 57% in those with BMIs of at least 35.
Data source: A retrospective observational study.
Disclosures: Dr. Winkle had no relevant financial relationships; Dr. Day reported a financial relationship with St. Jude Medical.
Sleep apnea may induce distinct form of atrial fibrillation
ORLANDO – Patients with atrial fibrillation (AF) should be screened for obstructive sleep apnea (OSA), because this information may be useful in guiding ablation strategies, according to results of a prospective study.
The study, which associated OSA in AF with a high relative rate of non–pulmonary vein (PV) triggers, has contributed to the “growing body of evidence implicating sleep apnea in atrial remodeling and promotion of the AF substrate,” Elad Anter, MD, associate director of the clinical electrophysiology laboratory at Beth Israel Deaconess Medical Center, Boston, reported at the annual International AF Symposium.
Despite the close association between OSA and AF, it has been unclear whether OSA is a causative factor. Dr. Anter suggested that mechanistic association is strengthening, however.
It has been hypothesized that OSA generates AF substrate through negative intrathoracic pressure changes and autonomic nervous system activation. But Dr. Anter reported that there is more recent and compelling evidence that the repetitive occlusions produced by OSA result in remodeling of the atria, producing scar tissue that slows conduction and produces susceptibility to reentry AF.
A newly completed prospective multicenter study adds support to this latter hypothesis. In the protocol, patients with paroxysmal AF scheduled for ablation were required to undergo a sleep study, an AF mapping study, and follow-up for at least 12 months. A known history of OSA was an exclusion criterion. To isolate the effect of OSA, there were exclusions for other major etiologies for AF, such as heart failure or coronary artery disease.
The AF mapping was conducted when patients were in sinus rhythm “to evaluate the baseline atrial substrate and avoid measurements related to acute electrical remodeling,” Dr. Anter explained.
Of 172 patients initially enrolled, 133 completed the sleep study, 118 completed the mapping study, and 110 completed both and were followed for at least 12 months. Of these, 43 patients without OSA were compared with 43 patients with OSA defined as an apnea-hypopnea index (AHI) of at least 15. Patients in the two groups did not differ significantly for relevant characteristics, such as body mass index (BMI), age, presence of hypertension, or duration of AF; but the left atrial (LA) volume was significantly greater (P = .01) in those with OSA than those without.
Even though the prevalence of voltage abnormalities was higher in the OSA group for the right (P = .01) and left atria (P = .0001) before ablation, the prevalence of PV triggers (63% vs. 65%), non-PV triggers (19% vs. 12%) and noninducible triggers (19% vs. 23%) were similar.
After ablation, PV triggers were no longer inducible in either group, but there was a striking difference in inducible non-PV triggers. While only 11.6% remained inducible in the non-OSA group, 41.8% (P = .003) remained inducible in the OSA patients.
“AF triggers in OSA were most commonly located at the LA septum, at the zone of low voltage and abnormal electrograms, as determined during sinus rhythm,” Dr. Anter reported. “Ablation of these triggers at the zone of tissue abnormality in the OSA patients resulted in termination of AF in 9 (64.2%) of the 14 patients.”
Overall, at the end of 12 months, 79% of those without OSA remained in arrhythmia-free survival, versus 65.1% of the group with OSA that were treated with PV isolation alone.
The lower rate of success in the OSA group shows the importance of specifically directing ablation to the areas of low voltage and slow conduction in the left anterior septum that Dr. Anter indicated otherwise would be missed.
“These zones are a common source of extra-PV triggers and localized circuits or rotors of AF in OSA patients,” he reported. “Ablation of these low voltage zones is associated with improved clinical outcome in OSA patients with paroxysmal AF.”
The data, which Dr. Anter said are consistent with a growing body of work regarding the relationship of OSA and AF, provided the basis for suggesting that AF patients undergo routine screening for OSA.
In patients with OSA, ablation of PV triggers alone even in paroxysmal PAF “may not be sufficient,” he cautioned. “Evaluation of non-PV triggers should also be performed.”
Dr. Anter reported financial relationships with Biosense Webster and Boston Scientific.
Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice and is associated with increased morbidity and mortality due to thromboembolism, stroke, and worsening of pre-existing heart failure. Both its incidence and prevalence are increasing as AF risk increases with advancing age.1 While the strategies of heart rate control and anticoagulation to lower stroke risk and rhythm control have been found comparable with regard to survival, many patients remain highly symptomatic because of palpitations and reduced cardiac output.1
Structural abnormalities of the atria, including fibrosis and dilation, accompanied by conduction abnormalities, provide the underlying substrate for AF. It is well established that AF episodes perpetuate atrial remodeling leading to more frequent and prolonged AF episodes. Hence, there is the long-standing notion that “AF begets AF.” While a variety of antiarrhythmic drugs have been employed over the years to prevent AF recurrences and to maintain sinus rhythm, their use has decreased over the past 2 decades due to their major side effects and their potential of proarrhythmia.
Since AF patients represent a heterogeneous group of patients with CV diseases of varying type and severity as well as comorbidities, it stands to reason that the pulmonary venous–left atrial junction may not be the sole culprit region of all cases of AF and that other anatomical locations might serve as triggers for AF.
In support of this notion are the results of the prospective multicenter study presented by Dr. Elad Anter at the annual International AF Symposium. This important study is consistent with and expands upon prior studies that have suggested that sites within the atria remote from the pulmonary veins may serve as triggers for AF, rather than lower technical success of pulmonary vein ablation.5 It further highlights the importance of fibrosis and associated electrical dispersion to the pathogenesis of AF.6 However, the recommendation that patients with AF be screened for OSA is not new, as nearly half of patients with AF also have OSA.7 While AF and OSA share common risk factors/comorbidities such as male gender, obesity, hypertension, coronary artery disease, and congestive heart failure, OSA has been found to be an independent risk factor for AF development.
It is important to know whether OSA was treated, as the presence of OSA raises the risk of AF recurrence and OSA treatment decreases AF recurrence after ablation.8,9 Conversely, in the setting of OSA, AF is more resistive to rhythm control. Enhanced vagal activation, elevated sympathetic tone, and oxidative stresses due to oxygen desaturation and left atrial distension have all been implicated in the pathogenesis linking OSA to the development of AF. Repeated increases in upper airway resistance during airway obstruction have been shown to lead to atrial stretch, dilation, and fibrosis.10 Since patients with heart failure, coronary artery disease, and other underlying causes for AF were excluded from the onset, the results may not be applicable to a large segment of AF patients. Exclusion of underlying cardiac conditions potentially raised the yield of patients found to have OSA and the potential value of OSA screening. Of note: Less than half of patients that were enrolled had complete data for analysis, which may further limit applicability of the study findings. All patients had paroxysmal AF and were in sinus rhythm while the mapping procedure was performed, leaving questions as to how to approach patients presenting acutely with persistent or long standing AF, or those recently treated with antiarrhythmic therapy. Also, since arrhythmia-free survival decreases from 1 to 5 years after AF ablation, and short-time success rates do not predict longer success rates, the present study results should be interpreted with cautious optimism.11
However, these limitations should not detract from the major implications of the study. In the setting of AF, OSA should be clinically suspected not only because of the frequent coexistence of the two disorders but because the presence of OSA should prompt electrophysiologists to consider non–pulmonary vein triggers of AF prior to ablation attempts. The consideration of alternative ablation sites might help to explain the lack of ablation procedure endpoints to predict long-term success of ablation and holds promise for increasing technical success rates. Given that airway obstruction may occur in other clinical settings such as seizure-induced laryngospasm and that seizures may induce arrhythmias and sudden death, there is potential for non–pulmonary vein sites to trigger AF and other arrhythmias in settings other than OSA as well.12 Whether other disease states are associated with a higher likelihood of non-pulmonary veins trigger sites also merits further study. Moreover, this study underscores the notion that with regard to AF ablation, “no one site fits all” and “clinical mapping” may serve as a valuable adjunct to anatomical mapping. It also serves as a reminder of the multidisciplinary nature of Chest Medicine and the need of a team oriented approach..
References
1. Iwasaki YK, Nishida K, Kato T, Nattel S. Atrial fibrillation pathophysiology: implications for management. Circulation. 2011;124:2264-74.
2. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015;372:1812-22.
3. Kuck KH, Brugada J, Fürnkranz A, et al. Cryoballoon or radiofrequency ablation for paroxysmal atrial fibrillation. N Engl J Med. 2016;374:2235-45.
4. Calkins H, Reynolds MR, Spector P, et al. Treatment of atrial fibrillation with antiarrhythmic drugs or radiofrequency ablation: two systematic literature reviews and meta-analyses. Circ Arrhythm Electrophysiol. 2009;2:349-61.
5. Narayan SM, Krummen DE, Shivkumar K, et al. Treatment of atrial fibrillation by the ablation of localized sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) trial. J Am Coll Cardiol. 2012;60:628-36.
6. Kottkamp H, Berg J, Bender R, et al. Box Isolation of Fibrotic Areas (BIFA): a patient-tailored substrate modified application approach for ablation of atrial fibrillation. J Cardiovasc Electrophysiol. 2016;27:22-30.
7. Stevenson IH, Teichtahl H, Cunnington D, et al. Prevalence of sleep disordered breathing in paroxysmal and persistent atrial fibrillation patients with normal left ventricular function. Eur Heart J. 2008;29:1662-9.
8. Fein AS, Shvilkin A, Shah D, et al. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol. 2013;62:300-5.
9. Naruse Y, Tada H, Satoh M, et al. Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy. Heart Rhythm. 2013;10:331-7.
10. Otto M, Belohlavek M, Romero-Corral A, et al. Comparison of cardiac structural and functional changes in obese otherwise healthy adults with versus without obstructive sleep apnea. Am J Cardiol. 2007;99:1298-302.
11. Kis Z, Muka T, Franco OH, et al. The short and long-term efficacy of pulmonary vein isolation as a sole treatment strategy for paroxysmal atrial fibrillation: a systematic review and meta-analysis. Curr Cardiol Rev. 2017 Jan 17. [Epub ahead of print].
12. Nakase K, Kollmar R, Lazar J, et al. Laryngospasm, central and obstructive apnea during seizures: defining pathophysiology for sudden death in a rat model. Epilepsy Res. 2016;128:126-39.
Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice and is associated with increased morbidity and mortality due to thromboembolism, stroke, and worsening of pre-existing heart failure. Both its incidence and prevalence are increasing as AF risk increases with advancing age.1 While the strategies of heart rate control and anticoagulation to lower stroke risk and rhythm control have been found comparable with regard to survival, many patients remain highly symptomatic because of palpitations and reduced cardiac output.1
Structural abnormalities of the atria, including fibrosis and dilation, accompanied by conduction abnormalities, provide the underlying substrate for AF. It is well established that AF episodes perpetuate atrial remodeling leading to more frequent and prolonged AF episodes. Hence, there is the long-standing notion that “AF begets AF.” While a variety of antiarrhythmic drugs have been employed over the years to prevent AF recurrences and to maintain sinus rhythm, their use has decreased over the past 2 decades due to their major side effects and their potential of proarrhythmia.
Since AF patients represent a heterogeneous group of patients with CV diseases of varying type and severity as well as comorbidities, it stands to reason that the pulmonary venous–left atrial junction may not be the sole culprit region of all cases of AF and that other anatomical locations might serve as triggers for AF.
In support of this notion are the results of the prospective multicenter study presented by Dr. Elad Anter at the annual International AF Symposium. This important study is consistent with and expands upon prior studies that have suggested that sites within the atria remote from the pulmonary veins may serve as triggers for AF, rather than lower technical success of pulmonary vein ablation.5 It further highlights the importance of fibrosis and associated electrical dispersion to the pathogenesis of AF.6 However, the recommendation that patients with AF be screened for OSA is not new, as nearly half of patients with AF also have OSA.7 While AF and OSA share common risk factors/comorbidities such as male gender, obesity, hypertension, coronary artery disease, and congestive heart failure, OSA has been found to be an independent risk factor for AF development.
It is important to know whether OSA was treated, as the presence of OSA raises the risk of AF recurrence and OSA treatment decreases AF recurrence after ablation.8,9 Conversely, in the setting of OSA, AF is more resistive to rhythm control. Enhanced vagal activation, elevated sympathetic tone, and oxidative stresses due to oxygen desaturation and left atrial distension have all been implicated in the pathogenesis linking OSA to the development of AF. Repeated increases in upper airway resistance during airway obstruction have been shown to lead to atrial stretch, dilation, and fibrosis.10 Since patients with heart failure, coronary artery disease, and other underlying causes for AF were excluded from the onset, the results may not be applicable to a large segment of AF patients. Exclusion of underlying cardiac conditions potentially raised the yield of patients found to have OSA and the potential value of OSA screening. Of note: Less than half of patients that were enrolled had complete data for analysis, which may further limit applicability of the study findings. All patients had paroxysmal AF and were in sinus rhythm while the mapping procedure was performed, leaving questions as to how to approach patients presenting acutely with persistent or long standing AF, or those recently treated with antiarrhythmic therapy. Also, since arrhythmia-free survival decreases from 1 to 5 years after AF ablation, and short-time success rates do not predict longer success rates, the present study results should be interpreted with cautious optimism.11
However, these limitations should not detract from the major implications of the study. In the setting of AF, OSA should be clinically suspected not only because of the frequent coexistence of the two disorders but because the presence of OSA should prompt electrophysiologists to consider non–pulmonary vein triggers of AF prior to ablation attempts. The consideration of alternative ablation sites might help to explain the lack of ablation procedure endpoints to predict long-term success of ablation and holds promise for increasing technical success rates. Given that airway obstruction may occur in other clinical settings such as seizure-induced laryngospasm and that seizures may induce arrhythmias and sudden death, there is potential for non–pulmonary vein sites to trigger AF and other arrhythmias in settings other than OSA as well.12 Whether other disease states are associated with a higher likelihood of non-pulmonary veins trigger sites also merits further study. Moreover, this study underscores the notion that with regard to AF ablation, “no one site fits all” and “clinical mapping” may serve as a valuable adjunct to anatomical mapping. It also serves as a reminder of the multidisciplinary nature of Chest Medicine and the need of a team oriented approach..
References
1. Iwasaki YK, Nishida K, Kato T, Nattel S. Atrial fibrillation pathophysiology: implications for management. Circulation. 2011;124:2264-74.
2. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015;372:1812-22.
3. Kuck KH, Brugada J, Fürnkranz A, et al. Cryoballoon or radiofrequency ablation for paroxysmal atrial fibrillation. N Engl J Med. 2016;374:2235-45.
4. Calkins H, Reynolds MR, Spector P, et al. Treatment of atrial fibrillation with antiarrhythmic drugs or radiofrequency ablation: two systematic literature reviews and meta-analyses. Circ Arrhythm Electrophysiol. 2009;2:349-61.
5. Narayan SM, Krummen DE, Shivkumar K, et al. Treatment of atrial fibrillation by the ablation of localized sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) trial. J Am Coll Cardiol. 2012;60:628-36.
6. Kottkamp H, Berg J, Bender R, et al. Box Isolation of Fibrotic Areas (BIFA): a patient-tailored substrate modified application approach for ablation of atrial fibrillation. J Cardiovasc Electrophysiol. 2016;27:22-30.
7. Stevenson IH, Teichtahl H, Cunnington D, et al. Prevalence of sleep disordered breathing in paroxysmal and persistent atrial fibrillation patients with normal left ventricular function. Eur Heart J. 2008;29:1662-9.
8. Fein AS, Shvilkin A, Shah D, et al. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol. 2013;62:300-5.
9. Naruse Y, Tada H, Satoh M, et al. Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy. Heart Rhythm. 2013;10:331-7.
10. Otto M, Belohlavek M, Romero-Corral A, et al. Comparison of cardiac structural and functional changes in obese otherwise healthy adults with versus without obstructive sleep apnea. Am J Cardiol. 2007;99:1298-302.
11. Kis Z, Muka T, Franco OH, et al. The short and long-term efficacy of pulmonary vein isolation as a sole treatment strategy for paroxysmal atrial fibrillation: a systematic review and meta-analysis. Curr Cardiol Rev. 2017 Jan 17. [Epub ahead of print].
12. Nakase K, Kollmar R, Lazar J, et al. Laryngospasm, central and obstructive apnea during seizures: defining pathophysiology for sudden death in a rat model. Epilepsy Res. 2016;128:126-39.
Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice and is associated with increased morbidity and mortality due to thromboembolism, stroke, and worsening of pre-existing heart failure. Both its incidence and prevalence are increasing as AF risk increases with advancing age.1 While the strategies of heart rate control and anticoagulation to lower stroke risk and rhythm control have been found comparable with regard to survival, many patients remain highly symptomatic because of palpitations and reduced cardiac output.1
Structural abnormalities of the atria, including fibrosis and dilation, accompanied by conduction abnormalities, provide the underlying substrate for AF. It is well established that AF episodes perpetuate atrial remodeling leading to more frequent and prolonged AF episodes. Hence, there is the long-standing notion that “AF begets AF.” While a variety of antiarrhythmic drugs have been employed over the years to prevent AF recurrences and to maintain sinus rhythm, their use has decreased over the past 2 decades due to their major side effects and their potential of proarrhythmia.
Since AF patients represent a heterogeneous group of patients with CV diseases of varying type and severity as well as comorbidities, it stands to reason that the pulmonary venous–left atrial junction may not be the sole culprit region of all cases of AF and that other anatomical locations might serve as triggers for AF.
In support of this notion are the results of the prospective multicenter study presented by Dr. Elad Anter at the annual International AF Symposium. This important study is consistent with and expands upon prior studies that have suggested that sites within the atria remote from the pulmonary veins may serve as triggers for AF, rather than lower technical success of pulmonary vein ablation.5 It further highlights the importance of fibrosis and associated electrical dispersion to the pathogenesis of AF.6 However, the recommendation that patients with AF be screened for OSA is not new, as nearly half of patients with AF also have OSA.7 While AF and OSA share common risk factors/comorbidities such as male gender, obesity, hypertension, coronary artery disease, and congestive heart failure, OSA has been found to be an independent risk factor for AF development.
It is important to know whether OSA was treated, as the presence of OSA raises the risk of AF recurrence and OSA treatment decreases AF recurrence after ablation.8,9 Conversely, in the setting of OSA, AF is more resistive to rhythm control. Enhanced vagal activation, elevated sympathetic tone, and oxidative stresses due to oxygen desaturation and left atrial distension have all been implicated in the pathogenesis linking OSA to the development of AF. Repeated increases in upper airway resistance during airway obstruction have been shown to lead to atrial stretch, dilation, and fibrosis.10 Since patients with heart failure, coronary artery disease, and other underlying causes for AF were excluded from the onset, the results may not be applicable to a large segment of AF patients. Exclusion of underlying cardiac conditions potentially raised the yield of patients found to have OSA and the potential value of OSA screening. Of note: Less than half of patients that were enrolled had complete data for analysis, which may further limit applicability of the study findings. All patients had paroxysmal AF and were in sinus rhythm while the mapping procedure was performed, leaving questions as to how to approach patients presenting acutely with persistent or long standing AF, or those recently treated with antiarrhythmic therapy. Also, since arrhythmia-free survival decreases from 1 to 5 years after AF ablation, and short-time success rates do not predict longer success rates, the present study results should be interpreted with cautious optimism.11
However, these limitations should not detract from the major implications of the study. In the setting of AF, OSA should be clinically suspected not only because of the frequent coexistence of the two disorders but because the presence of OSA should prompt electrophysiologists to consider non–pulmonary vein triggers of AF prior to ablation attempts. The consideration of alternative ablation sites might help to explain the lack of ablation procedure endpoints to predict long-term success of ablation and holds promise for increasing technical success rates. Given that airway obstruction may occur in other clinical settings such as seizure-induced laryngospasm and that seizures may induce arrhythmias and sudden death, there is potential for non–pulmonary vein sites to trigger AF and other arrhythmias in settings other than OSA as well.12 Whether other disease states are associated with a higher likelihood of non-pulmonary veins trigger sites also merits further study. Moreover, this study underscores the notion that with regard to AF ablation, “no one site fits all” and “clinical mapping” may serve as a valuable adjunct to anatomical mapping. It also serves as a reminder of the multidisciplinary nature of Chest Medicine and the need of a team oriented approach..
References
1. Iwasaki YK, Nishida K, Kato T, Nattel S. Atrial fibrillation pathophysiology: implications for management. Circulation. 2011;124:2264-74.
2. Verma A, Jiang CY, Betts TR, et al. Approaches to catheter ablation for persistent atrial fibrillation. N Engl J Med. 2015;372:1812-22.
3. Kuck KH, Brugada J, Fürnkranz A, et al. Cryoballoon or radiofrequency ablation for paroxysmal atrial fibrillation. N Engl J Med. 2016;374:2235-45.
4. Calkins H, Reynolds MR, Spector P, et al. Treatment of atrial fibrillation with antiarrhythmic drugs or radiofrequency ablation: two systematic literature reviews and meta-analyses. Circ Arrhythm Electrophysiol. 2009;2:349-61.
5. Narayan SM, Krummen DE, Shivkumar K, et al. Treatment of atrial fibrillation by the ablation of localized sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) trial. J Am Coll Cardiol. 2012;60:628-36.
6. Kottkamp H, Berg J, Bender R, et al. Box Isolation of Fibrotic Areas (BIFA): a patient-tailored substrate modified application approach for ablation of atrial fibrillation. J Cardiovasc Electrophysiol. 2016;27:22-30.
7. Stevenson IH, Teichtahl H, Cunnington D, et al. Prevalence of sleep disordered breathing in paroxysmal and persistent atrial fibrillation patients with normal left ventricular function. Eur Heart J. 2008;29:1662-9.
8. Fein AS, Shvilkin A, Shah D, et al. Treatment of obstructive sleep apnea reduces the risk of atrial fibrillation recurrence after catheter ablation. J Am Coll Cardiol. 2013;62:300-5.
9. Naruse Y, Tada H, Satoh M, et al. Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy. Heart Rhythm. 2013;10:331-7.
10. Otto M, Belohlavek M, Romero-Corral A, et al. Comparison of cardiac structural and functional changes in obese otherwise healthy adults with versus without obstructive sleep apnea. Am J Cardiol. 2007;99:1298-302.
11. Kis Z, Muka T, Franco OH, et al. The short and long-term efficacy of pulmonary vein isolation as a sole treatment strategy for paroxysmal atrial fibrillation: a systematic review and meta-analysis. Curr Cardiol Rev. 2017 Jan 17. [Epub ahead of print].
12. Nakase K, Kollmar R, Lazar J, et al. Laryngospasm, central and obstructive apnea during seizures: defining pathophysiology for sudden death in a rat model. Epilepsy Res. 2016;128:126-39.
ORLANDO – Patients with atrial fibrillation (AF) should be screened for obstructive sleep apnea (OSA), because this information may be useful in guiding ablation strategies, according to results of a prospective study.
The study, which associated OSA in AF with a high relative rate of non–pulmonary vein (PV) triggers, has contributed to the “growing body of evidence implicating sleep apnea in atrial remodeling and promotion of the AF substrate,” Elad Anter, MD, associate director of the clinical electrophysiology laboratory at Beth Israel Deaconess Medical Center, Boston, reported at the annual International AF Symposium.
Despite the close association between OSA and AF, it has been unclear whether OSA is a causative factor. Dr. Anter suggested that mechanistic association is strengthening, however.
It has been hypothesized that OSA generates AF substrate through negative intrathoracic pressure changes and autonomic nervous system activation. But Dr. Anter reported that there is more recent and compelling evidence that the repetitive occlusions produced by OSA result in remodeling of the atria, producing scar tissue that slows conduction and produces susceptibility to reentry AF.
A newly completed prospective multicenter study adds support to this latter hypothesis. In the protocol, patients with paroxysmal AF scheduled for ablation were required to undergo a sleep study, an AF mapping study, and follow-up for at least 12 months. A known history of OSA was an exclusion criterion. To isolate the effect of OSA, there were exclusions for other major etiologies for AF, such as heart failure or coronary artery disease.
The AF mapping was conducted when patients were in sinus rhythm “to evaluate the baseline atrial substrate and avoid measurements related to acute electrical remodeling,” Dr. Anter explained.
Of 172 patients initially enrolled, 133 completed the sleep study, 118 completed the mapping study, and 110 completed both and were followed for at least 12 months. Of these, 43 patients without OSA were compared with 43 patients with OSA defined as an apnea-hypopnea index (AHI) of at least 15. Patients in the two groups did not differ significantly for relevant characteristics, such as body mass index (BMI), age, presence of hypertension, or duration of AF; but the left atrial (LA) volume was significantly greater (P = .01) in those with OSA than those without.
Even though the prevalence of voltage abnormalities was higher in the OSA group for the right (P = .01) and left atria (P = .0001) before ablation, the prevalence of PV triggers (63% vs. 65%), non-PV triggers (19% vs. 12%) and noninducible triggers (19% vs. 23%) were similar.
After ablation, PV triggers were no longer inducible in either group, but there was a striking difference in inducible non-PV triggers. While only 11.6% remained inducible in the non-OSA group, 41.8% (P = .003) remained inducible in the OSA patients.
“AF triggers in OSA were most commonly located at the LA septum, at the zone of low voltage and abnormal electrograms, as determined during sinus rhythm,” Dr. Anter reported. “Ablation of these triggers at the zone of tissue abnormality in the OSA patients resulted in termination of AF in 9 (64.2%) of the 14 patients.”
Overall, at the end of 12 months, 79% of those without OSA remained in arrhythmia-free survival, versus 65.1% of the group with OSA that were treated with PV isolation alone.
The lower rate of success in the OSA group shows the importance of specifically directing ablation to the areas of low voltage and slow conduction in the left anterior septum that Dr. Anter indicated otherwise would be missed.
“These zones are a common source of extra-PV triggers and localized circuits or rotors of AF in OSA patients,” he reported. “Ablation of these low voltage zones is associated with improved clinical outcome in OSA patients with paroxysmal AF.”
The data, which Dr. Anter said are consistent with a growing body of work regarding the relationship of OSA and AF, provided the basis for suggesting that AF patients undergo routine screening for OSA.
In patients with OSA, ablation of PV triggers alone even in paroxysmal PAF “may not be sufficient,” he cautioned. “Evaluation of non-PV triggers should also be performed.”
Dr. Anter reported financial relationships with Biosense Webster and Boston Scientific.
ORLANDO – Patients with atrial fibrillation (AF) should be screened for obstructive sleep apnea (OSA), because this information may be useful in guiding ablation strategies, according to results of a prospective study.
The study, which associated OSA in AF with a high relative rate of non–pulmonary vein (PV) triggers, has contributed to the “growing body of evidence implicating sleep apnea in atrial remodeling and promotion of the AF substrate,” Elad Anter, MD, associate director of the clinical electrophysiology laboratory at Beth Israel Deaconess Medical Center, Boston, reported at the annual International AF Symposium.
Despite the close association between OSA and AF, it has been unclear whether OSA is a causative factor. Dr. Anter suggested that mechanistic association is strengthening, however.
It has been hypothesized that OSA generates AF substrate through negative intrathoracic pressure changes and autonomic nervous system activation. But Dr. Anter reported that there is more recent and compelling evidence that the repetitive occlusions produced by OSA result in remodeling of the atria, producing scar tissue that slows conduction and produces susceptibility to reentry AF.
A newly completed prospective multicenter study adds support to this latter hypothesis. In the protocol, patients with paroxysmal AF scheduled for ablation were required to undergo a sleep study, an AF mapping study, and follow-up for at least 12 months. A known history of OSA was an exclusion criterion. To isolate the effect of OSA, there were exclusions for other major etiologies for AF, such as heart failure or coronary artery disease.
The AF mapping was conducted when patients were in sinus rhythm “to evaluate the baseline atrial substrate and avoid measurements related to acute electrical remodeling,” Dr. Anter explained.
Of 172 patients initially enrolled, 133 completed the sleep study, 118 completed the mapping study, and 110 completed both and were followed for at least 12 months. Of these, 43 patients without OSA were compared with 43 patients with OSA defined as an apnea-hypopnea index (AHI) of at least 15. Patients in the two groups did not differ significantly for relevant characteristics, such as body mass index (BMI), age, presence of hypertension, or duration of AF; but the left atrial (LA) volume was significantly greater (P = .01) in those with OSA than those without.
Even though the prevalence of voltage abnormalities was higher in the OSA group for the right (P = .01) and left atria (P = .0001) before ablation, the prevalence of PV triggers (63% vs. 65%), non-PV triggers (19% vs. 12%) and noninducible triggers (19% vs. 23%) were similar.
After ablation, PV triggers were no longer inducible in either group, but there was a striking difference in inducible non-PV triggers. While only 11.6% remained inducible in the non-OSA group, 41.8% (P = .003) remained inducible in the OSA patients.
“AF triggers in OSA were most commonly located at the LA septum, at the zone of low voltage and abnormal electrograms, as determined during sinus rhythm,” Dr. Anter reported. “Ablation of these triggers at the zone of tissue abnormality in the OSA patients resulted in termination of AF in 9 (64.2%) of the 14 patients.”
Overall, at the end of 12 months, 79% of those without OSA remained in arrhythmia-free survival, versus 65.1% of the group with OSA that were treated with PV isolation alone.
The lower rate of success in the OSA group shows the importance of specifically directing ablation to the areas of low voltage and slow conduction in the left anterior septum that Dr. Anter indicated otherwise would be missed.
“These zones are a common source of extra-PV triggers and localized circuits or rotors of AF in OSA patients,” he reported. “Ablation of these low voltage zones is associated with improved clinical outcome in OSA patients with paroxysmal AF.”
The data, which Dr. Anter said are consistent with a growing body of work regarding the relationship of OSA and AF, provided the basis for suggesting that AF patients undergo routine screening for OSA.
In patients with OSA, ablation of PV triggers alone even in paroxysmal PAF “may not be sufficient,” he cautioned. “Evaluation of non-PV triggers should also be performed.”
Dr. Anter reported financial relationships with Biosense Webster and Boston Scientific.
Key clinical point: Atrial fibrillation associated with sleep apnea appears to have features that should be addressed specifically for sustained rhythm control.
Major finding: AF patients with sleep apnea have more non–pulmonary vein triggers after ablation than do those without sleep apnea (41.8% vs. 11.6%).
Data source: A prospective multicenter observational study.
Disclosures: Dr. Anter reported financial relationships with Biosense Webster and Boston Scientific.
Intracardiac echo safely guides LAA occluder placement
ORLANDO – Intracardiac echocardiography (ICE) can be safely substituted for transesophageal echocardiography (TEE) as a less invasive option in the placement of an investigational percutaneous device for left atrial appendage (LAA) occlusion, according to data presented at the annual International AF Symposium.
The relative safety and efficacy of ICE and TEE for placement of the device, called the Amplatzer Amulet, was evaluated as a subanalysis of a large, nonrandomized, observational study, according to Boris Schmidt, MD, of Cardiovascular Center Bethanien, Frankfurt, Germany.
The Amplatzer Amulet device, which is designed to prevent LAA-associated thromboembolism in patients with nonvalvular atrial fibrillation (AF), has been available in Europe for several years. It functions much like Boston Scientific’s Watchman implant. A registration trial in the United States was initiated in 2016.
In the study that provided the basis for this analysis, 1,088 AF patients were implanted. The average age was 75 years, and the population was relatively high risk for both stroke and bleeding. The CHA2DS2-VASc score was at least 4 in 65% of patients, with an average score of 4.2. Prior stroke (28%) and transient ischemic attack (11%) had occurred in more than one-third. Reflecting the fact that 72% had a history of a major bleed, the average HAS-BLED score was 3.3. More than 80% were hypertensive.
The decision to place the device with TEE, which Dr. Schmidt characterized as the standard, or ICE was left up to the discretion of the implanter. Ultimately, 958 (88.4%) of the devices were placed with TEE and 126 (11.6%) with ICE.
There were no significant differences in implant success or safety when the two methods for guiding implantation were compared. Specifically, success was achieved in 99.2% of the ICE group with 90.5% of cases requiring only one device. In the TEE group, the device was successfully implanted in 98.4%, and 94.4% needed only one device. The first device to be selected was ultimately implanted in 96.5% of the ICE group and 94.4% of the TEE group. The LAA closure rate, defined as gap of less than 3 mm, was 100% at implant and 3 months after transplant in the ICE group, when evaluated by an independent core laboratory. The closure rates in the TEE group at the time of implant and 3 months later were 99.8% and 98.6%, respectively. No difference between imaging methods approached statistical significance.
Adverse events, which were also adjudicated by independent investigators, occurred at low rates and also did not differ by imaging strategy. In the ICE and TEE groups, respectively, these included vascular complications in 0.9% and 1.6%, pericardial effusion in 1.0% and 0.8%, stroke in 0.3% and 0%, and embolization in 0.1% and 0%. With a median follow-up of 6.6 months, there have been four deaths. Two were considered to be device related by the adjudicators. One involved a perforation and another a cardiac arrest. Both were observed in the TEE group.
The Amplatzer Amulet device consists of a lobe that is designed to fit inside the LAA neck and a disk that provides a complete seal at the orifice. It was first introduced in Europe in 2008 but has undergone several modifications. In the United States, the Watchman, which opens like an umbrella in order to block passage of thromboemboli when deployed in the LAA, received FDA approval in 2015. Other LAA closure strategies are in development. There are no large randomized trials in which LAA closure devices have been compared.
Dr. Schmidt has financial relationships with Boston Scientific and St. Jude Medical.
ORLANDO – Intracardiac echocardiography (ICE) can be safely substituted for transesophageal echocardiography (TEE) as a less invasive option in the placement of an investigational percutaneous device for left atrial appendage (LAA) occlusion, according to data presented at the annual International AF Symposium.
The relative safety and efficacy of ICE and TEE for placement of the device, called the Amplatzer Amulet, was evaluated as a subanalysis of a large, nonrandomized, observational study, according to Boris Schmidt, MD, of Cardiovascular Center Bethanien, Frankfurt, Germany.
The Amplatzer Amulet device, which is designed to prevent LAA-associated thromboembolism in patients with nonvalvular atrial fibrillation (AF), has been available in Europe for several years. It functions much like Boston Scientific’s Watchman implant. A registration trial in the United States was initiated in 2016.
In the study that provided the basis for this analysis, 1,088 AF patients were implanted. The average age was 75 years, and the population was relatively high risk for both stroke and bleeding. The CHA2DS2-VASc score was at least 4 in 65% of patients, with an average score of 4.2. Prior stroke (28%) and transient ischemic attack (11%) had occurred in more than one-third. Reflecting the fact that 72% had a history of a major bleed, the average HAS-BLED score was 3.3. More than 80% were hypertensive.
The decision to place the device with TEE, which Dr. Schmidt characterized as the standard, or ICE was left up to the discretion of the implanter. Ultimately, 958 (88.4%) of the devices were placed with TEE and 126 (11.6%) with ICE.
There were no significant differences in implant success or safety when the two methods for guiding implantation were compared. Specifically, success was achieved in 99.2% of the ICE group with 90.5% of cases requiring only one device. In the TEE group, the device was successfully implanted in 98.4%, and 94.4% needed only one device. The first device to be selected was ultimately implanted in 96.5% of the ICE group and 94.4% of the TEE group. The LAA closure rate, defined as gap of less than 3 mm, was 100% at implant and 3 months after transplant in the ICE group, when evaluated by an independent core laboratory. The closure rates in the TEE group at the time of implant and 3 months later were 99.8% and 98.6%, respectively. No difference between imaging methods approached statistical significance.
Adverse events, which were also adjudicated by independent investigators, occurred at low rates and also did not differ by imaging strategy. In the ICE and TEE groups, respectively, these included vascular complications in 0.9% and 1.6%, pericardial effusion in 1.0% and 0.8%, stroke in 0.3% and 0%, and embolization in 0.1% and 0%. With a median follow-up of 6.6 months, there have been four deaths. Two were considered to be device related by the adjudicators. One involved a perforation and another a cardiac arrest. Both were observed in the TEE group.
The Amplatzer Amulet device consists of a lobe that is designed to fit inside the LAA neck and a disk that provides a complete seal at the orifice. It was first introduced in Europe in 2008 but has undergone several modifications. In the United States, the Watchman, which opens like an umbrella in order to block passage of thromboemboli when deployed in the LAA, received FDA approval in 2015. Other LAA closure strategies are in development. There are no large randomized trials in which LAA closure devices have been compared.
Dr. Schmidt has financial relationships with Boston Scientific and St. Jude Medical.
ORLANDO – Intracardiac echocardiography (ICE) can be safely substituted for transesophageal echocardiography (TEE) as a less invasive option in the placement of an investigational percutaneous device for left atrial appendage (LAA) occlusion, according to data presented at the annual International AF Symposium.
The relative safety and efficacy of ICE and TEE for placement of the device, called the Amplatzer Amulet, was evaluated as a subanalysis of a large, nonrandomized, observational study, according to Boris Schmidt, MD, of Cardiovascular Center Bethanien, Frankfurt, Germany.
The Amplatzer Amulet device, which is designed to prevent LAA-associated thromboembolism in patients with nonvalvular atrial fibrillation (AF), has been available in Europe for several years. It functions much like Boston Scientific’s Watchman implant. A registration trial in the United States was initiated in 2016.
In the study that provided the basis for this analysis, 1,088 AF patients were implanted. The average age was 75 years, and the population was relatively high risk for both stroke and bleeding. The CHA2DS2-VASc score was at least 4 in 65% of patients, with an average score of 4.2. Prior stroke (28%) and transient ischemic attack (11%) had occurred in more than one-third. Reflecting the fact that 72% had a history of a major bleed, the average HAS-BLED score was 3.3. More than 80% were hypertensive.
The decision to place the device with TEE, which Dr. Schmidt characterized as the standard, or ICE was left up to the discretion of the implanter. Ultimately, 958 (88.4%) of the devices were placed with TEE and 126 (11.6%) with ICE.
There were no significant differences in implant success or safety when the two methods for guiding implantation were compared. Specifically, success was achieved in 99.2% of the ICE group with 90.5% of cases requiring only one device. In the TEE group, the device was successfully implanted in 98.4%, and 94.4% needed only one device. The first device to be selected was ultimately implanted in 96.5% of the ICE group and 94.4% of the TEE group. The LAA closure rate, defined as gap of less than 3 mm, was 100% at implant and 3 months after transplant in the ICE group, when evaluated by an independent core laboratory. The closure rates in the TEE group at the time of implant and 3 months later were 99.8% and 98.6%, respectively. No difference between imaging methods approached statistical significance.
Adverse events, which were also adjudicated by independent investigators, occurred at low rates and also did not differ by imaging strategy. In the ICE and TEE groups, respectively, these included vascular complications in 0.9% and 1.6%, pericardial effusion in 1.0% and 0.8%, stroke in 0.3% and 0%, and embolization in 0.1% and 0%. With a median follow-up of 6.6 months, there have been four deaths. Two were considered to be device related by the adjudicators. One involved a perforation and another a cardiac arrest. Both were observed in the TEE group.
The Amplatzer Amulet device consists of a lobe that is designed to fit inside the LAA neck and a disk that provides a complete seal at the orifice. It was first introduced in Europe in 2008 but has undergone several modifications. In the United States, the Watchman, which opens like an umbrella in order to block passage of thromboemboli when deployed in the LAA, received FDA approval in 2015. Other LAA closure strategies are in development. There are no large randomized trials in which LAA closure devices have been compared.
Dr. Schmidt has financial relationships with Boston Scientific and St. Jude Medical.
Key clinical point: Intracardiac echocardiography is a viable option for guiding placement of an experimental left atrial appendage thromboembolism blocker.
Major finding: LAA closure rates at 3 months were 100% with ICE and 98.6% with transesophageal echocardiograph.
Data source: Prospective, multicenter, observational study.
Disclosures: Dr. Schmidt has financial relationships with Boston Scientific and St. Jude Medical.
Atrial fib management pathway lowers hospital admissions
ORLANDO – An atrial fibrillation treatment pathway designed specifically to reduce the proportion of patients with this complaint who are admitted to the hospital from the emergency department was found remarkably effective in a pilot study presented at the annual International AF Symposium.
“In this single-center observational study, a multidisciplinary AF pathway was associated with fivefold reduction in admission rate and 2.5-fold reduction in length of stay for those who were admitted,” reported Jeremy N. Ruskin, MD.
Relative to many other countries, admission rates for AF in the United States are “extremely high,” according to Dr. Ruskin, director of the cardiac arrhythmia service at Massachusetts General Hospital, Boston. Citing 2013 figures from the Nationwide Emergency Department Sample (NEDS) database, rates ranged between 60% and 80% by geographic region with an average of about 66%. In contrast and as an example of lower rates elsewhere, fewer than 40% of AF patients with similar characteristics presenting at emergency departments in Ontario, Can., were admitted. Similarly low admission rates have been reported in Europe.
The AF pathway tested in the study at Mass General was developed through collaboration between electrophysiologists and emergency department physicians. It is suitable for patients presenting with a primary complaint of AF without concomitant diseases, such as sepsis or myocardial infarction. Patients were entered into this study after it was shown that AF was the chief complaint. The first step was to determine whether participants were best suited to a rhythm control or rate control strategy.
“The rhythm control group was anticoagulated and then underwent expedited cardioversion with TEE (transesophageal echocardiogram) if necessary. The rate control group was anticoagulated and then given appropriate pharmacologic therapy,” Dr. Ruskin explained. Once patients were on treatment, an electrophysiologist and an emergency room physician evaluated response. Stable patients were discharged; unstable patients were admitted.
In this nonrandomized observational study conducted over a 1-year period, 94 patients were managed with the AF pathway. Admissions and outcomes in this group were compared with 265 patients who received usual care.
Only 16% of those managed through the AF pathway were admitted versus 80% (P less than .001) in the usual care group. Among those admitted, length of stay was shorter in patients managed along the AF pathway relative to usual care (32 vs. 85 hours; P = .002). Dr. Ruskin also reported that both the cardioversion rate and the proportion of patients discharged on novel oral anticoagulation drugs were higher in the AF pathway group.
The reductions in hospital admissions would be expected to translate into large reductions in costs, particularly as follow-up showed no difference in return visits to the hospital between those entered into the AF pathway relative to those who received routine care, according to Dr. Ruskin. Emphasizing the cost burden of AF admissions, he noted that the estimated charges for the more than 300,000 AF admissions in U.S. hospitals in 2013 exceeded $7 billion.
Currently, there are no guidelines for managing AF in the emergency department, and there is wide variation in practice among centers, according to Dr. Ruskin. He provided data from the NEDS database demonstrating highly significant variations in rates of admission by geographic region (for example, rates were more than 10% higher in the northeast vs. the west) and hospital type (for example, rates were twice as high in metropolitan than nonmetropolitan hospitals).
In the NEDS database, various patient characteristics were associated with increased odds ratios for admission. These included hypertension (OR, 2.3), valvular disease (OR, 3.6), and congestive heart failure (OR, 3.7). However, Dr. Ruskin indicated that patients with these or other characteristics associated with increased likelihood of admission, such as older age, have better outcomes with hospitalization.
The data from this initial observational study were recently published (Am J Cardiol. 2016 Jul 1;118[1]:64-71), and a larger prospective study with this AF pathway is already underway at both Mass General and at Brigham and Women’s Hospital, Boston. If the data confirm that AF admissions can be safely reduced through this pathway, Dr. Ruskin anticipates that implementation will be adopted at other hospitals in the Harvard system.
Dr. Ruskin reported financial relationships with Cardiome, Daiichi Sankyo, Gilead, InCarda Therapeutics, InfoBionic, Laguna Medical, Medtronic, Pfizer, and Portola.
ORLANDO – An atrial fibrillation treatment pathway designed specifically to reduce the proportion of patients with this complaint who are admitted to the hospital from the emergency department was found remarkably effective in a pilot study presented at the annual International AF Symposium.
“In this single-center observational study, a multidisciplinary AF pathway was associated with fivefold reduction in admission rate and 2.5-fold reduction in length of stay for those who were admitted,” reported Jeremy N. Ruskin, MD.
Relative to many other countries, admission rates for AF in the United States are “extremely high,” according to Dr. Ruskin, director of the cardiac arrhythmia service at Massachusetts General Hospital, Boston. Citing 2013 figures from the Nationwide Emergency Department Sample (NEDS) database, rates ranged between 60% and 80% by geographic region with an average of about 66%. In contrast and as an example of lower rates elsewhere, fewer than 40% of AF patients with similar characteristics presenting at emergency departments in Ontario, Can., were admitted. Similarly low admission rates have been reported in Europe.
The AF pathway tested in the study at Mass General was developed through collaboration between electrophysiologists and emergency department physicians. It is suitable for patients presenting with a primary complaint of AF without concomitant diseases, such as sepsis or myocardial infarction. Patients were entered into this study after it was shown that AF was the chief complaint. The first step was to determine whether participants were best suited to a rhythm control or rate control strategy.
“The rhythm control group was anticoagulated and then underwent expedited cardioversion with TEE (transesophageal echocardiogram) if necessary. The rate control group was anticoagulated and then given appropriate pharmacologic therapy,” Dr. Ruskin explained. Once patients were on treatment, an electrophysiologist and an emergency room physician evaluated response. Stable patients were discharged; unstable patients were admitted.
In this nonrandomized observational study conducted over a 1-year period, 94 patients were managed with the AF pathway. Admissions and outcomes in this group were compared with 265 patients who received usual care.
Only 16% of those managed through the AF pathway were admitted versus 80% (P less than .001) in the usual care group. Among those admitted, length of stay was shorter in patients managed along the AF pathway relative to usual care (32 vs. 85 hours; P = .002). Dr. Ruskin also reported that both the cardioversion rate and the proportion of patients discharged on novel oral anticoagulation drugs were higher in the AF pathway group.
The reductions in hospital admissions would be expected to translate into large reductions in costs, particularly as follow-up showed no difference in return visits to the hospital between those entered into the AF pathway relative to those who received routine care, according to Dr. Ruskin. Emphasizing the cost burden of AF admissions, he noted that the estimated charges for the more than 300,000 AF admissions in U.S. hospitals in 2013 exceeded $7 billion.
Currently, there are no guidelines for managing AF in the emergency department, and there is wide variation in practice among centers, according to Dr. Ruskin. He provided data from the NEDS database demonstrating highly significant variations in rates of admission by geographic region (for example, rates were more than 10% higher in the northeast vs. the west) and hospital type (for example, rates were twice as high in metropolitan than nonmetropolitan hospitals).
In the NEDS database, various patient characteristics were associated with increased odds ratios for admission. These included hypertension (OR, 2.3), valvular disease (OR, 3.6), and congestive heart failure (OR, 3.7). However, Dr. Ruskin indicated that patients with these or other characteristics associated with increased likelihood of admission, such as older age, have better outcomes with hospitalization.
The data from this initial observational study were recently published (Am J Cardiol. 2016 Jul 1;118[1]:64-71), and a larger prospective study with this AF pathway is already underway at both Mass General and at Brigham and Women’s Hospital, Boston. If the data confirm that AF admissions can be safely reduced through this pathway, Dr. Ruskin anticipates that implementation will be adopted at other hospitals in the Harvard system.
Dr. Ruskin reported financial relationships with Cardiome, Daiichi Sankyo, Gilead, InCarda Therapeutics, InfoBionic, Laguna Medical, Medtronic, Pfizer, and Portola.
ORLANDO – An atrial fibrillation treatment pathway designed specifically to reduce the proportion of patients with this complaint who are admitted to the hospital from the emergency department was found remarkably effective in a pilot study presented at the annual International AF Symposium.
“In this single-center observational study, a multidisciplinary AF pathway was associated with fivefold reduction in admission rate and 2.5-fold reduction in length of stay for those who were admitted,” reported Jeremy N. Ruskin, MD.
Relative to many other countries, admission rates for AF in the United States are “extremely high,” according to Dr. Ruskin, director of the cardiac arrhythmia service at Massachusetts General Hospital, Boston. Citing 2013 figures from the Nationwide Emergency Department Sample (NEDS) database, rates ranged between 60% and 80% by geographic region with an average of about 66%. In contrast and as an example of lower rates elsewhere, fewer than 40% of AF patients with similar characteristics presenting at emergency departments in Ontario, Can., were admitted. Similarly low admission rates have been reported in Europe.
The AF pathway tested in the study at Mass General was developed through collaboration between electrophysiologists and emergency department physicians. It is suitable for patients presenting with a primary complaint of AF without concomitant diseases, such as sepsis or myocardial infarction. Patients were entered into this study after it was shown that AF was the chief complaint. The first step was to determine whether participants were best suited to a rhythm control or rate control strategy.
“The rhythm control group was anticoagulated and then underwent expedited cardioversion with TEE (transesophageal echocardiogram) if necessary. The rate control group was anticoagulated and then given appropriate pharmacologic therapy,” Dr. Ruskin explained. Once patients were on treatment, an electrophysiologist and an emergency room physician evaluated response. Stable patients were discharged; unstable patients were admitted.
In this nonrandomized observational study conducted over a 1-year period, 94 patients were managed with the AF pathway. Admissions and outcomes in this group were compared with 265 patients who received usual care.
Only 16% of those managed through the AF pathway were admitted versus 80% (P less than .001) in the usual care group. Among those admitted, length of stay was shorter in patients managed along the AF pathway relative to usual care (32 vs. 85 hours; P = .002). Dr. Ruskin also reported that both the cardioversion rate and the proportion of patients discharged on novel oral anticoagulation drugs were higher in the AF pathway group.
The reductions in hospital admissions would be expected to translate into large reductions in costs, particularly as follow-up showed no difference in return visits to the hospital between those entered into the AF pathway relative to those who received routine care, according to Dr. Ruskin. Emphasizing the cost burden of AF admissions, he noted that the estimated charges for the more than 300,000 AF admissions in U.S. hospitals in 2013 exceeded $7 billion.
Currently, there are no guidelines for managing AF in the emergency department, and there is wide variation in practice among centers, according to Dr. Ruskin. He provided data from the NEDS database demonstrating highly significant variations in rates of admission by geographic region (for example, rates were more than 10% higher in the northeast vs. the west) and hospital type (for example, rates were twice as high in metropolitan than nonmetropolitan hospitals).
In the NEDS database, various patient characteristics were associated with increased odds ratios for admission. These included hypertension (OR, 2.3), valvular disease (OR, 3.6), and congestive heart failure (OR, 3.7). However, Dr. Ruskin indicated that patients with these or other characteristics associated with increased likelihood of admission, such as older age, have better outcomes with hospitalization.
The data from this initial observational study were recently published (Am J Cardiol. 2016 Jul 1;118[1]:64-71), and a larger prospective study with this AF pathway is already underway at both Mass General and at Brigham and Women’s Hospital, Boston. If the data confirm that AF admissions can be safely reduced through this pathway, Dr. Ruskin anticipates that implementation will be adopted at other hospitals in the Harvard system.
Dr. Ruskin reported financial relationships with Cardiome, Daiichi Sankyo, Gilead, InCarda Therapeutics, InfoBionic, Laguna Medical, Medtronic, Pfizer, and Portola.
Key clinical point: An atrial fibrillation (AF) treatment pathway in the emergency department reduces hospital admission rates.
Major finding: Once implemented, the AF hospital admission rate at one institution fell significantly, from 80% to 16%.
Data source: Prospective observational study.
Disclosures: Dr. Ruskin reports financial relationships with Cardiome, Daiichi Sankyo, Gilead, InCarda Therapeutics, InfoBionic, Laguna Medical, Medtronic, Pfizer, and Portola.