Ablation for Atrial Fibrillation in Congestive Heart Failure
http://www.100md.com
《新英格兰医药杂志》
To the Editor: Hsu et al. report on a study (Dec. 2 issue)1 of catheter ablation and its effect on rhythm control in patients with atrial fibrillation and heart failure to support the notion that drug-free maintenance of sinus rhythm may be superior to rate control. We want to stress, however, that apart from the acute risks associated with ablation, as noted by Stevenson and Stevenson in the accompanying editorial,2 patients who have this treatment face a continuous threat of other problems after the procedure. First, some patients still have recurrences of atrial fibrillation that require antiarrhythmic drugs. Second, recurrences of atrial fibrillation may go unnoticed and lead to recurrent heart failure. Third, the Atrial Fibrillation Follow-up Investigation of Rhythm Management and Rate Control versus Electrical Cardioversion trials have shown that strokes may occur even while patients are in sinus rhythm.3,4 Though these strokes are partly caused by recurrent atrial fibrillation, they also occur because of associated disease, which obviously is not cured by ablation. This means that we do not know whether it is safe to stop anticoagulant therapy. Finally, rhythm control may unmask the sick sinus syndrome and the need for a pacemaker, which is not possible with rate control.
Harry I.G.M. Crijns, M.D., Ph.D.
Robert G. Tieleman, M.D., Ph.D.
University Hospital Maastricht
6202 AZ Maastricht, the Netherlands
h.cryns@cardio.azm.nl
Isabelle C. Van Gelder, M.D., Ph.D.
University Hospital Groningen
9700 RB Groningen, the Netherlands
References
Hsu L-F, Ja?s P, Sanders P, et al. Catheter ablation for atrial fibrillation in congestive heart failure. N Engl J Med 2004;351:2373-2383.
Stevenson WG, Stevenson LW. Atrial fibrillation and heart failure -- five more years. N Engl J Med 2004;351:2437-2440.
Wyse DG, Waldo AL, DiMarco JP, et al. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-1833.
Van Gelder IC, Hagens VE, Bosker HA, et al. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med 2002;347:1834-1840.
To the Editor: Hsu et al. overestimate the hemodynamic consequences of a lack of atrial contraction in patients with left ventricular systolic dysfunction who are in atrial fibrillation. Atrial systole improves left ventricular performance as a result of the impact on ventricular preload.1 In patients with left ventricular systolic dysfunction, the heart generally functions on a "flat" portion of the Frank–Starling curve, gaining little hemodynamic benefit from increased preload. Patients with systolic dysfunction in atrial fibrillation who undergo successful ablation probably have a hemodynamic benefit that results from a regularization of ventricular rhythm and ensured rate control. This can be accomplished more easily and safely with an "ablate-and-pace" strategy, in which biventricular pacing is used to negate the adverse effects of long-term right ventricular pacing.2 However, left ventricular filling in patients with diastolic dysfunction occurs primarily in late diastole; such patients may be more dependent on atrial contraction.3 Perhaps we should focus attention on the use of catheter ablation for atrial fibrillation in the increasingly recognized population of patients with heart failure due to diastolic dysfunction, in whom atrial fibrillation is exceedingly common.4
Anil K. Gehi, M.D.
Davendra Mehta, M.D., Ph.D.
Mt. Sinai School of Medicine
New York, NY 10029
anil.gehi@msnyuhealth.org
References
Linderer T, Chatterjee K, Parmley WW, Sievers RE, Glantz SA, Tyberg JV. Influence of atrial systole on the Frank-Starling relation and the end-diastolic pressure-diameter relation of the left ventricle. Circulation 1983;67:1045-1053.
Doshi R, Daoud E, Fellows C, et al. PAVE: the first prospective, randomized study evaluating biventricular pacing after ablate and pace therapy. Presented at the American College of Cardiology Annual Scientific Session 2004, New Orleans, March 7–10, 2004.
Bonow RO, Frederick TM, Bacharach SL, et al. Atrial systole and left ventricular filling in hypertrophic cardiomyopathy: effect of verapamil. Am J Cardiol 1983;51:1386-1391.
Tsang TS, Gersh BJ, Appleton CP, et al. Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women. J Am Coll Cardiol 2002;40:1636-1644.
The authors reply: Dr. Crijns and colleagues rightly point out that after undergoing catheter ablation for atrial fibrillation, patients are still at risk for other disorders, particularly those related to recurrences of arrhythmia; this is true for any treatment strategy. In our article, we stressed that ablation as a treatment for atrial fibrillation, especially for permanent atrial fibrillation, is associated with a not insignificant recurrence rate. We agree that it is difficult to detect asymptomatic recurrences, which, alone or with coexisting conditions, pose a potential risk of recurrent heart failure and stroke, and that further studies are required to assess when and in which patients anticoagulant therapy may be safely stopped. In our study, this was determined on a patient-by-patient basis for those considered to be free of atrial fibrillation for at least six months.
At present, there is no evidence that ablation of atrial fibrillation may unmask the sick sinus syndrome. On the contrary, cure of atrial fibrillation may result in reverse remodeling of sinus-node function, which, together with cessation of drugs, obviates the need for pacemakers in patients with apparent sinus-node disease.1 Finally, this study afforded us the opportunity to assess the role of "true" rhythm control without antiarrhythmic drugs, and our observations have been reproduced by the group from the Cleveland Clinic.2
Although we agree with the points raised by Drs. Gehi and Mehta regarding the hemodynamic contribution of the atrium, these observations do not fully explain our findings, particularly the improvement in left ventricular function observed in patients with adequate rate control. Although our study was not designed to identify the mechanisms responsible for improvement in left ventricular function, it is unlikely that rate control and regularization of rhythm, as observed with the "ablate-and-pace" strategy, account for these observations. Clinically, loss of atrial transport and atrioventricular synchrony have been observed to reduce cardiac output by up to 20 percent.3 In all prior studies that used the ablate-and-pace strategy, improvement in left ventricular function was limited, even with biventricular pacing.4 Studies that compare ablation of atrial fibrillation with the ablate-and-pace strategy and that use biventricular pacing may be desirable. Finally, we agree that strategies for the use of catheter ablation for atrial fibrillation should be expanded to include patients with diastolic dysfunction.
Li-Fern Hsu, M.B., B.S.
Michel Ha?ssaguerre, M.D.
Pierre Ja?s, M.D.
H?pital Cardiologique de Haut-Lévêque
33604 Bordeaux-Pessac, France
pierre.jais@chu-bordeaux.fr
References
Hocini M, Sanders P, Deisenhofer I, et al. Reverse remodeling of sinus node function after catheter ablation of atrial fibrillation in patients with prolonged sinus pauses. Circulation 2003;108:1172-1175.
Chen MS, Marrouche NF, Khaykin Y, et al. Pulmonary vein isolation for the treatment of atrial fibrillation in patients with impaired systolic function. J Am Coll Cardiol 2004;43:1004-1009.
Maisel WH, Stevenson LW. Atrial fibrillation in heart failure: epidemiology, pathophysiology, and rationale for therapy. Am J Cardiol 2003;91:Suppl:2D-8D.
Doshi R, Daoud E, Fellows C, et al. PAVE: the first prospective, randomized study evaluating biventricular pacing after ablate and pace therapy. Presented at the American College of Cardiology Annual Scientific Session 2004, New Orleans, March 7–10, 2004.
Harry I.G.M. Crijns, M.D., Ph.D.
Robert G. Tieleman, M.D., Ph.D.
University Hospital Maastricht
6202 AZ Maastricht, the Netherlands
h.cryns@cardio.azm.nl
Isabelle C. Van Gelder, M.D., Ph.D.
University Hospital Groningen
9700 RB Groningen, the Netherlands
References
Hsu L-F, Ja?s P, Sanders P, et al. Catheter ablation for atrial fibrillation in congestive heart failure. N Engl J Med 2004;351:2373-2383.
Stevenson WG, Stevenson LW. Atrial fibrillation and heart failure -- five more years. N Engl J Med 2004;351:2437-2440.
Wyse DG, Waldo AL, DiMarco JP, et al. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-1833.
Van Gelder IC, Hagens VE, Bosker HA, et al. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med 2002;347:1834-1840.
To the Editor: Hsu et al. overestimate the hemodynamic consequences of a lack of atrial contraction in patients with left ventricular systolic dysfunction who are in atrial fibrillation. Atrial systole improves left ventricular performance as a result of the impact on ventricular preload.1 In patients with left ventricular systolic dysfunction, the heart generally functions on a "flat" portion of the Frank–Starling curve, gaining little hemodynamic benefit from increased preload. Patients with systolic dysfunction in atrial fibrillation who undergo successful ablation probably have a hemodynamic benefit that results from a regularization of ventricular rhythm and ensured rate control. This can be accomplished more easily and safely with an "ablate-and-pace" strategy, in which biventricular pacing is used to negate the adverse effects of long-term right ventricular pacing.2 However, left ventricular filling in patients with diastolic dysfunction occurs primarily in late diastole; such patients may be more dependent on atrial contraction.3 Perhaps we should focus attention on the use of catheter ablation for atrial fibrillation in the increasingly recognized population of patients with heart failure due to diastolic dysfunction, in whom atrial fibrillation is exceedingly common.4
Anil K. Gehi, M.D.
Davendra Mehta, M.D., Ph.D.
Mt. Sinai School of Medicine
New York, NY 10029
anil.gehi@msnyuhealth.org
References
Linderer T, Chatterjee K, Parmley WW, Sievers RE, Glantz SA, Tyberg JV. Influence of atrial systole on the Frank-Starling relation and the end-diastolic pressure-diameter relation of the left ventricle. Circulation 1983;67:1045-1053.
Doshi R, Daoud E, Fellows C, et al. PAVE: the first prospective, randomized study evaluating biventricular pacing after ablate and pace therapy. Presented at the American College of Cardiology Annual Scientific Session 2004, New Orleans, March 7–10, 2004.
Bonow RO, Frederick TM, Bacharach SL, et al. Atrial systole and left ventricular filling in hypertrophic cardiomyopathy: effect of verapamil. Am J Cardiol 1983;51:1386-1391.
Tsang TS, Gersh BJ, Appleton CP, et al. Left ventricular diastolic dysfunction as a predictor of the first diagnosed nonvalvular atrial fibrillation in 840 elderly men and women. J Am Coll Cardiol 2002;40:1636-1644.
The authors reply: Dr. Crijns and colleagues rightly point out that after undergoing catheter ablation for atrial fibrillation, patients are still at risk for other disorders, particularly those related to recurrences of arrhythmia; this is true for any treatment strategy. In our article, we stressed that ablation as a treatment for atrial fibrillation, especially for permanent atrial fibrillation, is associated with a not insignificant recurrence rate. We agree that it is difficult to detect asymptomatic recurrences, which, alone or with coexisting conditions, pose a potential risk of recurrent heart failure and stroke, and that further studies are required to assess when and in which patients anticoagulant therapy may be safely stopped. In our study, this was determined on a patient-by-patient basis for those considered to be free of atrial fibrillation for at least six months.
At present, there is no evidence that ablation of atrial fibrillation may unmask the sick sinus syndrome. On the contrary, cure of atrial fibrillation may result in reverse remodeling of sinus-node function, which, together with cessation of drugs, obviates the need for pacemakers in patients with apparent sinus-node disease.1 Finally, this study afforded us the opportunity to assess the role of "true" rhythm control without antiarrhythmic drugs, and our observations have been reproduced by the group from the Cleveland Clinic.2
Although we agree with the points raised by Drs. Gehi and Mehta regarding the hemodynamic contribution of the atrium, these observations do not fully explain our findings, particularly the improvement in left ventricular function observed in patients with adequate rate control. Although our study was not designed to identify the mechanisms responsible for improvement in left ventricular function, it is unlikely that rate control and regularization of rhythm, as observed with the "ablate-and-pace" strategy, account for these observations. Clinically, loss of atrial transport and atrioventricular synchrony have been observed to reduce cardiac output by up to 20 percent.3 In all prior studies that used the ablate-and-pace strategy, improvement in left ventricular function was limited, even with biventricular pacing.4 Studies that compare ablation of atrial fibrillation with the ablate-and-pace strategy and that use biventricular pacing may be desirable. Finally, we agree that strategies for the use of catheter ablation for atrial fibrillation should be expanded to include patients with diastolic dysfunction.
Li-Fern Hsu, M.B., B.S.
Michel Ha?ssaguerre, M.D.
Pierre Ja?s, M.D.
H?pital Cardiologique de Haut-Lévêque
33604 Bordeaux-Pessac, France
pierre.jais@chu-bordeaux.fr
References
Hocini M, Sanders P, Deisenhofer I, et al. Reverse remodeling of sinus node function after catheter ablation of atrial fibrillation in patients with prolonged sinus pauses. Circulation 2003;108:1172-1175.
Chen MS, Marrouche NF, Khaykin Y, et al. Pulmonary vein isolation for the treatment of atrial fibrillation in patients with impaired systolic function. J Am Coll Cardiol 2004;43:1004-1009.
Maisel WH, Stevenson LW. Atrial fibrillation in heart failure: epidemiology, pathophysiology, and rationale for therapy. Am J Cardiol 2003;91:Suppl:2D-8D.
Doshi R, Daoud E, Fellows C, et al. PAVE: the first prospective, randomized study evaluating biventricular pacing after ablate and pace therapy. Presented at the American College of Cardiology Annual Scientific Session 2004, New Orleans, March 7–10, 2004.