Circumferential Pulmonary-Vein Ablation for Atrial Fibrillation
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《新英格兰医药杂志》
To the Editor: In their study of circumferential pulmonary-vein ablation in patients with chronic atrial fibrillation, Oral et al. (March 2 issue)1 do not mention evaluation or discuss the potential complication of pulmonary-vein stenosis. In their definition of ostial stenosis, they rely on the electroanatomical "tube depiction" method as a guide; this is a suboptimal method for exact ostial demarcation since the tubes are automatically centralized around the acquired points. Any movement by the patient can also make electroanatomical mapping even more inaccurate.
Although the authors report no follow-up for the assessment of pulmonary-vein stenosis, a recent study involving magnetic resonance imaging detected a variable degree of stenosis in 38 percent of pulmonary veins ablated with the use of the electroanatomical approach.2 A recent worldwide survey has shown that pulmonary-vein stenosis occurs in about 1.3 percent of patients.3 In addition, the authors mention that a patient died of pneumonia after ablation. However, they give no details about any further diagnostic investigation. Many reports, including one by Salamon et al.4 in the same issue of the Journal, have emphasized that pulmonary-vein stenosis is associated with symptoms that may mimic common lung diseases, which can lead to unnecessary diagnostic and therapeutic procedures.5
Oussama Musbah Wazni, M.D.
Tamer S. Fahmy, M.D.
Andrea Natale, M.D.
Cleveland Clinic Foundation
Cleveland, OH 44195
References
Oral H, Pappone C, Chugh A, et al. Circumferential pulmonary-vein ablation for chronic atrial fibrillation. N Engl J Med 2006;354:934-941.
Dong J, Vasamreddy CR, Jayam V, et al. Incidence and predictors of pulmonary vein stenosis following catheter ablation of atrial fibrillation using the anatomic pulmonary vein ablation approach: results from paired magnetic resonance imaging. J Cardiovasc Electrophysiol 2005;16:845-852.
Cappato R, Calkins H, Chen SA, et al. Worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circulation 2005;111:1100-1105.
Salamon F, Hirsch R, Tur-Kaspa R, Kramer MR. Search for the complication. N Engl J Med 2006;354:957-963.
Saad EB, Marrouche NF, Saad CP, et al. Pulmonary vein stenosis after catheter ablation of atrial fibrillation: emergence of a new clinical syndrome. Ann Intern Med 2003;138:634-638.
To the Editor: Oral et al. report that "there were no complications" in a trial of catheter ablation for atrial fibrillation. This conclusion lacks meaning without consideration of the limited power of the study to detect rare but clinically significant events. The incidence of atrioesophageal fistula associated with this procedure has been estimated at less than 1 percent.1 Even if the incidence were as high as 2 percent, the study by Oral et al. had less than 5 percent power to detect such a difference. Moreover, the authors followed patients for only 12 months after the procedure — a period that may be insufficient for the detection of occurrences of pulmonary-vein stenosis.2
The determination of the efficacy of a treatment with the use of a superiority design does not allow investigators to conclude that rates of adverse events are equivalent.3 Guidelines for the reporting of adverse events have been proposed that emphasize the need to discuss the limited power of trials to detect rare occurrences.4 This generally relevant consideration5 takes on increased importance when an adverse event is already recognized and potentially catastrophic.1
Scott K. Aberegg, M.D., M.P.H.
Ohio State University College of Medicine and Public Health
Columbus, OH 43210
scottaberegg@hotmail.com
David Majure, M.D., M.P.H.
Johns Hopkins School of Medicine
Baltimore, MD 21205
References
Doll N, Borger MA, Fabricius A, et al. Esophageal perforation during left atrial radiofrequency ablation: is the risk too high? J Thorac Cardiovasc Surg 2003;125:836-842.
Arentz T, Jander N, von Rosenthal J, et al. Incidence of pulmonary vein stenosis 2 years after radiofrequency catheter ablation of refractory atrial fibrillation. Eur Heart J 2003;24:963-969.
Piaggio G, Elbourne DR, Altman DG, Pocock SJ, Evans SJW. Reporting of noninferiority and equivalence randomized trials: an extension of the CONSORT Statement. JAMA 2006;295:1152-1160.
Ioannidis JPA, Evans SJW, Gotzsche PC, et al. Better reporting of harms in randomized trials: an extension of the CONSORT statement. Ann Intern Med 2004;141:781-788.
Bresalier RS, Sandler RS, Quan H, et al. Cardiovascular events associated with rofecoxib in a colorectal adenoma chemoprevention trial. N Engl J Med 2005;352:1092-1102.
To the Editor: In the study by Oral et al., the mean age of patients who were randomly assigned to undergo pulmonary-vein ablation was 55 years, and about 92 percent of them did not have structural heart disease. The study population was highly selected and was not representative of the general population of patients with chronic atrial fibrillation.1 Thus, it is premature to conclude that sinus rhythm can be maintained in the long term in the majority of patients with chronic atrial fibrillation by means of pulmonary-vein ablation. Such a conclusion can be misleading, considering that most patients with chronic atrial fibrillation are elderly and that thromboembolism is one of the leading causes of complications and death associated with atrial fibrillation.1
The results of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial2 should be applied to the majority of patients with chronic atrial fibrillation, and appropriate antithrombotic strategies should not be replaced by attempts to maintain sinus rhythm by catheter ablation. On the basis of currently available data, highly selected younger patients whose condition is refractory to medical treatment and who do not have structural heart disease3 may be most likely to benefit from catheter ablation for paroxysmal or chronic atrial fibrillation.
Johann Auer, M.D.
Gudrun Lamm, M.D.
Bernd Eber, M.D.
General Hospital Wels
A-4600 Wels, Austria
johann.auer@klinikum-wels.at
References
Fuster V, Ryden LE, Asinger RW, et al. ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients with Atrial Fibrillation) developed in collaboration with the North American Society of Pacing and Electrophysiology. Circulation 2001;104:2118-2150.
The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-1833.
Wazni OM, Marrouche NF, Martin DO, et al. Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of symptomatic atrial fibrillation: a randomized trial. JAMA 2005;293:2634-2640.
The authors reply: The risk of pulmonary-vein stenosis depends on the ablation technique, energy source, maximum power and temperature, and whether energy was delivered within pulmonary veins. Circumferential pulmonary-vein ablation is performed outside the pulmonary veins. A previous study demonstrated that the procedure was not associated with any significant pulmonary-vein stenosis.1 However, we do understand the concern of Wazni et al. regarding pulmonary-vein stenosis.2 In the study by Dong et al.,3 unlike this study, linear lesions were created between the ipsilateral superior and inferior pulmonary veins, which increased the risk of stenosis. Dong et al. reported in the same study that stenosis occurred only when this line was created. The worldwide survey included patients from 100 centers that used a variety of techniques between 1995 and 2002. Therefore, these findings may not be representative of current practice, particularly when the rapid evolution of ablation strategies and techniques is considered. In our study, the 66-year-old man who died had a fatal case of Stenotrophomonas maltophilia pneumonia after surgical intervention for an aortic aneurysm seven months after the ablation.
Aberegg and Majure point out that our study did not have sufficient power to assess safety. However, as indicated, the primary end point was efficacy. Because the incidence of atrioesophageal fistula is very low, more than 1700 patients would be required in each group for a study to detect a difference at a power of 0.90. Because atrioesophageal fistula is a rare but often fatal complication, it was discussed in detail. Nevertheless, large-scale multicenter trials with an extended duration will be necessary to determine the ultimate safety of ablation in the treatment of atrial fibrillation. However, because ablation strategies are still evolving, such trials may not be feasible in the near future.
We agree with Auer et al. that the study population was not representative of all patients with chronic atrial fibrillation. However, we strongly disagree that the AFFIRM results should be applied to the majority of patients with atrial fibrillation. As discussed, there are important differences between the subjects of the AFFIRM trial and those in our study, since patients in the AFFIRM study were older (mean age, 70±9), had at least one risk factor for stroke, and were unlikely to have debilitating symptoms caused by the atrial fibrillation. Furthermore, sinus rhythm was maintained in only one third of the rhythm-control group. We believe that our study has demonstrated that catheter ablation is a reasonable option for younger patients whose quality of life is disturbed by chronic atrial fibrillation and whose condition has not responded well to drug therapy or cardioversion.
Hakan Oral, M.D.
University of Michigan
Ann Arbor, MI 48109
oralh@umich.edu
Carlo Pappone, M.D.
San Raffaele University Hospital
20132 Milan, Italy
Fred Morady, M.D.
University of Michigan
Ann Arbor, MI 48109
References
Lemola K, Sneider M, Desjardins B, et al. Effects of left atrial ablation of atrial fibrillation on size of the left atrium and pulmonary veins. Heart Rhythm 2004;1:576-581.
Qureshi AM, Prieto LR, Latson LA, et al. Transcatheter angioplasty for acquired pulmonary vein stenosis after radiofrequency ablation. Circulation 2003;108:1336-1342.
Dong J, Vasamreddy CR, Jayam V, et al. Incidence and predictors of pulmonary vein stenosis following catheter ablation of atrial fibrillation using the anatomic pulmonary vein ablation approach: results from paired magnetic resonance imaging. J Cardiovasc Electrophysiol 2005;16:845-852.
The editorialists reply: In our editorial1 accompanying the study by Oral et al., we stated, "According to the latest guidelines of the American Heart Association , the American College of Cardiology , and the European Society of Cardiology , catheter ablation is considered standard therapy for patients who have symptomatic paroxysmal atrial fibrillation after having had no response to a single antiarrhythmic drug." This statement is incorrect, since the only approved guidelines on this topic are those from 2001, rather than those we cited as being currently "in press." Although a revision is under development, it has not been completed. The current policy of the organizations regarding this issue can be found in the 2001 ACC–AHA–ESC guidelines on atrial fibrillation.2
In addition, our statement and the accompanying citation violate the confidentiality policies of these three organizations for the development of guidelines — policies that are specifically designed to prevent premature distribution of draft recommendations that are not yet approved, as was done in this case. We deeply regret the inclusion of misleading information about the position of the organizations in our editorial and our erroneous citation of the guidelines as being "in press," as well as our violation of the policies of the organizations regarding the development of guidelines.
Mark A. Wood, M.D.
Kenneth A. Ellenbogen, M.D.
Virginia Commonwealth University Medical Center
Richmond, VA 23284
References
Wood MA, Ellenbogen KA. Catheter ablation of chronic atrial fibrillation -- the gap between promise and practice. N Engl J Med 2006;354:967-969.
Fuster V, Rydén LE, Asinger RW, et al. ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients with Atrial Fibrillation): developed in collaboration with the North American Society of Pacing and Electrophysiology. J Am Coll Cardiol 2001;38:1231-1266.
Although the authors report no follow-up for the assessment of pulmonary-vein stenosis, a recent study involving magnetic resonance imaging detected a variable degree of stenosis in 38 percent of pulmonary veins ablated with the use of the electroanatomical approach.2 A recent worldwide survey has shown that pulmonary-vein stenosis occurs in about 1.3 percent of patients.3 In addition, the authors mention that a patient died of pneumonia after ablation. However, they give no details about any further diagnostic investigation. Many reports, including one by Salamon et al.4 in the same issue of the Journal, have emphasized that pulmonary-vein stenosis is associated with symptoms that may mimic common lung diseases, which can lead to unnecessary diagnostic and therapeutic procedures.5
Oussama Musbah Wazni, M.D.
Tamer S. Fahmy, M.D.
Andrea Natale, M.D.
Cleveland Clinic Foundation
Cleveland, OH 44195
References
Oral H, Pappone C, Chugh A, et al. Circumferential pulmonary-vein ablation for chronic atrial fibrillation. N Engl J Med 2006;354:934-941.
Dong J, Vasamreddy CR, Jayam V, et al. Incidence and predictors of pulmonary vein stenosis following catheter ablation of atrial fibrillation using the anatomic pulmonary vein ablation approach: results from paired magnetic resonance imaging. J Cardiovasc Electrophysiol 2005;16:845-852.
Cappato R, Calkins H, Chen SA, et al. Worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation. Circulation 2005;111:1100-1105.
Salamon F, Hirsch R, Tur-Kaspa R, Kramer MR. Search for the complication. N Engl J Med 2006;354:957-963.
Saad EB, Marrouche NF, Saad CP, et al. Pulmonary vein stenosis after catheter ablation of atrial fibrillation: emergence of a new clinical syndrome. Ann Intern Med 2003;138:634-638.
To the Editor: Oral et al. report that "there were no complications" in a trial of catheter ablation for atrial fibrillation. This conclusion lacks meaning without consideration of the limited power of the study to detect rare but clinically significant events. The incidence of atrioesophageal fistula associated with this procedure has been estimated at less than 1 percent.1 Even if the incidence were as high as 2 percent, the study by Oral et al. had less than 5 percent power to detect such a difference. Moreover, the authors followed patients for only 12 months after the procedure — a period that may be insufficient for the detection of occurrences of pulmonary-vein stenosis.2
The determination of the efficacy of a treatment with the use of a superiority design does not allow investigators to conclude that rates of adverse events are equivalent.3 Guidelines for the reporting of adverse events have been proposed that emphasize the need to discuss the limited power of trials to detect rare occurrences.4 This generally relevant consideration5 takes on increased importance when an adverse event is already recognized and potentially catastrophic.1
Scott K. Aberegg, M.D., M.P.H.
Ohio State University College of Medicine and Public Health
Columbus, OH 43210
scottaberegg@hotmail.com
David Majure, M.D., M.P.H.
Johns Hopkins School of Medicine
Baltimore, MD 21205
References
Doll N, Borger MA, Fabricius A, et al. Esophageal perforation during left atrial radiofrequency ablation: is the risk too high? J Thorac Cardiovasc Surg 2003;125:836-842.
Arentz T, Jander N, von Rosenthal J, et al. Incidence of pulmonary vein stenosis 2 years after radiofrequency catheter ablation of refractory atrial fibrillation. Eur Heart J 2003;24:963-969.
Piaggio G, Elbourne DR, Altman DG, Pocock SJ, Evans SJW. Reporting of noninferiority and equivalence randomized trials: an extension of the CONSORT Statement. JAMA 2006;295:1152-1160.
Ioannidis JPA, Evans SJW, Gotzsche PC, et al. Better reporting of harms in randomized trials: an extension of the CONSORT statement. Ann Intern Med 2004;141:781-788.
Bresalier RS, Sandler RS, Quan H, et al. Cardiovascular events associated with rofecoxib in a colorectal adenoma chemoprevention trial. N Engl J Med 2005;352:1092-1102.
To the Editor: In the study by Oral et al., the mean age of patients who were randomly assigned to undergo pulmonary-vein ablation was 55 years, and about 92 percent of them did not have structural heart disease. The study population was highly selected and was not representative of the general population of patients with chronic atrial fibrillation.1 Thus, it is premature to conclude that sinus rhythm can be maintained in the long term in the majority of patients with chronic atrial fibrillation by means of pulmonary-vein ablation. Such a conclusion can be misleading, considering that most patients with chronic atrial fibrillation are elderly and that thromboembolism is one of the leading causes of complications and death associated with atrial fibrillation.1
The results of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial2 should be applied to the majority of patients with chronic atrial fibrillation, and appropriate antithrombotic strategies should not be replaced by attempts to maintain sinus rhythm by catheter ablation. On the basis of currently available data, highly selected younger patients whose condition is refractory to medical treatment and who do not have structural heart disease3 may be most likely to benefit from catheter ablation for paroxysmal or chronic atrial fibrillation.
Johann Auer, M.D.
Gudrun Lamm, M.D.
Bernd Eber, M.D.
General Hospital Wels
A-4600 Wels, Austria
johann.auer@klinikum-wels.at
References
Fuster V, Ryden LE, Asinger RW, et al. ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients with Atrial Fibrillation) developed in collaboration with the North American Society of Pacing and Electrophysiology. Circulation 2001;104:2118-2150.
The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-1833.
Wazni OM, Marrouche NF, Martin DO, et al. Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of symptomatic atrial fibrillation: a randomized trial. JAMA 2005;293:2634-2640.
The authors reply: The risk of pulmonary-vein stenosis depends on the ablation technique, energy source, maximum power and temperature, and whether energy was delivered within pulmonary veins. Circumferential pulmonary-vein ablation is performed outside the pulmonary veins. A previous study demonstrated that the procedure was not associated with any significant pulmonary-vein stenosis.1 However, we do understand the concern of Wazni et al. regarding pulmonary-vein stenosis.2 In the study by Dong et al.,3 unlike this study, linear lesions were created between the ipsilateral superior and inferior pulmonary veins, which increased the risk of stenosis. Dong et al. reported in the same study that stenosis occurred only when this line was created. The worldwide survey included patients from 100 centers that used a variety of techniques between 1995 and 2002. Therefore, these findings may not be representative of current practice, particularly when the rapid evolution of ablation strategies and techniques is considered. In our study, the 66-year-old man who died had a fatal case of Stenotrophomonas maltophilia pneumonia after surgical intervention for an aortic aneurysm seven months after the ablation.
Aberegg and Majure point out that our study did not have sufficient power to assess safety. However, as indicated, the primary end point was efficacy. Because the incidence of atrioesophageal fistula is very low, more than 1700 patients would be required in each group for a study to detect a difference at a power of 0.90. Because atrioesophageal fistula is a rare but often fatal complication, it was discussed in detail. Nevertheless, large-scale multicenter trials with an extended duration will be necessary to determine the ultimate safety of ablation in the treatment of atrial fibrillation. However, because ablation strategies are still evolving, such trials may not be feasible in the near future.
We agree with Auer et al. that the study population was not representative of all patients with chronic atrial fibrillation. However, we strongly disagree that the AFFIRM results should be applied to the majority of patients with atrial fibrillation. As discussed, there are important differences between the subjects of the AFFIRM trial and those in our study, since patients in the AFFIRM study were older (mean age, 70±9), had at least one risk factor for stroke, and were unlikely to have debilitating symptoms caused by the atrial fibrillation. Furthermore, sinus rhythm was maintained in only one third of the rhythm-control group. We believe that our study has demonstrated that catheter ablation is a reasonable option for younger patients whose quality of life is disturbed by chronic atrial fibrillation and whose condition has not responded well to drug therapy or cardioversion.
Hakan Oral, M.D.
University of Michigan
Ann Arbor, MI 48109
oralh@umich.edu
Carlo Pappone, M.D.
San Raffaele University Hospital
20132 Milan, Italy
Fred Morady, M.D.
University of Michigan
Ann Arbor, MI 48109
References
Lemola K, Sneider M, Desjardins B, et al. Effects of left atrial ablation of atrial fibrillation on size of the left atrium and pulmonary veins. Heart Rhythm 2004;1:576-581.
Qureshi AM, Prieto LR, Latson LA, et al. Transcatheter angioplasty for acquired pulmonary vein stenosis after radiofrequency ablation. Circulation 2003;108:1336-1342.
Dong J, Vasamreddy CR, Jayam V, et al. Incidence and predictors of pulmonary vein stenosis following catheter ablation of atrial fibrillation using the anatomic pulmonary vein ablation approach: results from paired magnetic resonance imaging. J Cardiovasc Electrophysiol 2005;16:845-852.
The editorialists reply: In our editorial1 accompanying the study by Oral et al., we stated, "According to the latest guidelines of the American Heart Association , the American College of Cardiology , and the European Society of Cardiology , catheter ablation is considered standard therapy for patients who have symptomatic paroxysmal atrial fibrillation after having had no response to a single antiarrhythmic drug." This statement is incorrect, since the only approved guidelines on this topic are those from 2001, rather than those we cited as being currently "in press." Although a revision is under development, it has not been completed. The current policy of the organizations regarding this issue can be found in the 2001 ACC–AHA–ESC guidelines on atrial fibrillation.2
In addition, our statement and the accompanying citation violate the confidentiality policies of these three organizations for the development of guidelines — policies that are specifically designed to prevent premature distribution of draft recommendations that are not yet approved, as was done in this case. We deeply regret the inclusion of misleading information about the position of the organizations in our editorial and our erroneous citation of the guidelines as being "in press," as well as our violation of the policies of the organizations regarding the development of guidelines.
Mark A. Wood, M.D.
Kenneth A. Ellenbogen, M.D.
Virginia Commonwealth University Medical Center
Richmond, VA 23284
References
Wood MA, Ellenbogen KA. Catheter ablation of chronic atrial fibrillation -- the gap between promise and practice. N Engl J Med 2006;354:967-969.
Fuster V, Rydén LE, Asinger RW, et al. ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients with Atrial Fibrillation): developed in collaboration with the North American Society of Pacing and Electrophysiology. J Am Coll Cardiol 2001;38:1231-1266.