By Ashley Starkweather, B.S. and Asher Kimchi M.D.

Bordeaux-Pessac, France – In a study of 58 patients with atrial fibrillation and congestive heart failure, catheter ablation was found to improve cardiac function, quality of life, and exercise capacity by restoring and maintaining sinus rhythm. The results of this study were published by Li-Fern Hsu, M.B., B.S., from the Hopital Cardiologique du Haut-Leveque in Bordeaux-Pessac, France, in the December 2, 2004 issue of the New England Journal of Medicine. 

Congestive heart failure and atrial fibrillation often coexist, each promoting the existence of the other. When trying to maintain sinus rhythm in patients with atrial fibrillation complicated by congestive heart failure, antiarrhythmic drugs often prove to have low efficacy or potentially harmful side effects. This study evaluated the effects of restoring and maintaining sinus rhythm via catheter ablation in this subgroup of patients in order to avoid the use of antiarrhythmic drugs.  

In the study, investigators enrolled 58 consecutive patients with congestive heart failure of NYHA Class II who were undergoing curative ablation for atrial fibrillation that was resistant to at least two antiarrhythmic drugs and had a left ventricular ejection fraction of less than 45 percent. These patients were matched for age, sex, and classification of atrial fibrillation with procedural controls during the same time period from March 2001 to March 2004. 

Patients were admitted two days prior to ablation and oral anticoagulants were stopped on admission. Anti-arrhythmic drugs were stopped prior to the procedure. Heart rate and rhythm were monitored by 48 hour ambulatory electrocardiography, and transesophageal echocardiography was performed to rule out atrial thrombi prior to ablation. Transthoracic echocardiography was used to assess left ventricle size and function. The ablation procedure aimed to electrically isolate all the pulmonary veins and to create a complete obstacle to electrical conduction. Post-ablation, anticoagulation therapy was reinitiated, and patients were monitored for three days. Patients were also tested for baseline exercise capacity on a bicycle stress test. 

Follow-up required rehospitalization at 1, 3, 6, and 12 months after the last ablation procedure, and consisted of clinical interviews, 48-hour electrocardiographic monitoring, transthoracic echocardiography, and exercise testing. Anticoagulation was discontinued if sinus rhythm was maintained for three to six months. Symptoms and quality of life were assessed at 3 and 12 months. 

The results of the study showed an improvement in cardiac function after establishing and maintaining sinus rhythm from catheter ablation. NYHA congestive heart failure class improved from a mean of 2.3 to 1.4 at the one month mark, and stayed at that level. Exercise time and capacity increased significantly, from mean time of 11 minutes to 15 minutes (P<0.001) and mean maximal capacity from 123 to 144 W (P<0.001) during the follow-up period. The left ventricular ejection fraction increased by a mean of 21 percent, with the greatest improvement seen in the first three months. The Symptom Checklist-Frequency and Severity scores and SF-36 quality of life measures improved significantly as well. 

In conclusion, after catheter ablation for atrial fibrillation, long term restoration of sinus rhythm, without the use of antiarrhythmic drugs, resulted in significant improvement in left ventricular function, exercise capacity, symptoms, and quality of life. Furthermore, while this study did not directly assess the effect on mortality, because a reduced ejection fraction is an important predictor of mortality, the significant improvement in left ventricular function after ablation could be important in improving survival. 

Co-authors: Pierre Jais, M.D.; Prashanthan Sanders, M.B., B.S., Ph.D.; Stephane Garrigue, M.D., Ph.D.; Meleze Hocini, M.D.; Frederic Sacher, M.D.; Yoshihide Takahashi, M.D.; Martin Rotter, M.D.; Jean-Luc Pasquie, M.D., Ph.D.; Christophe Scavee, M.D.; Pierre Bordachar, M.D.; Jacques Clementy, M.D.; and Michael Haissaguerre, M.D.