The two approaches to the treatment of atrial fibrillation - rate control and chronic oral anticoagulation, and rhythm control with cardioversion and antiarrhythmic drugs are compared in two landmark North American and European studies (NEJM Volume 347, Number 23, December 5, 2002).
Rhythm control did not offer a survival advantage and was associated with higher rates of adverse drug effects than rate control. Rate control is sufficient and sometimes the preferable approach for treatment of persistent atrial fibrillation with anticoagulation (to prevent embolic complication) with either strategy.
A Comparison of Rate Control and Rhythm Control in Patients with Atrial Fibrillation
The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators
Background There are two approaches to the treatment of atrial fibrillation: one is cardioversion and treatment with antiarrhythmic drugs to maintain sinus rhythm, and the other is the use of rate-controlling drugs, allowing atrial fibrillation to persist. In both approaches, the use of anticoagulant drugs is recommended.
Methods We conducted a randomized, multicenter comparison of these two treatment strategies in patients with atrial fibrillation and a high risk of stroke or death. The primary end point was overall mortality.
Results A total of 4060 patients (mean [±SD] age, 69.7±9.0 years) were enrolled in the study; 70.8 percent had a history of hypertension, and 38.2 percent had coronary artery disease. Of the 3311 patients with echocardiograms, the left atrium was enlarged in 64.7 percent and left ventricular function was depressed in 26.0 percent. There were 356 deaths among the patients assigned to rhythm-control therapy and 310 deaths among those assigned to rate-control therapy (mortality at five years, 23.8 percent and 21.3 percent, respectively; hazard ratio, 1.15 [95 percent confidence interval, 0.99 to 1.34]; P=0.08). More patients in the rhythm-control group than in the rate-control group were hospitalized, and there were more adverse drug effects in the rhythm-control group as well. In both groups, the majority of strokes occurred after warfarin had been stopped or when the international normalized ratio was subtherapeutic.
Conclusions Management of atrial fibrillation with the rhythm-control strategy offers no survival advantage over the rate-control strategy, and there are potential advantages, such as a lower risk of adverse drug effects, with the rate-control strategy. Anticoagulation should be continued in this group of high-risk patients.
The AFFIRM writing group (D.G. Wyse, A.L. Waldo, J.P. DiMarco, M.J. Domanski, Y. Rosenberg, E.B. Schron, J.C. Kellen, H.L. Greene, M.C. Mickel, J.E. Dalquist, and S.D. Corley) assumes overall responsibility for the content of the manuscript.
Address reprint requests to the AFFIRM Clinical Trial Center, Axio Research, 2601 4th Ave., Ste. 200, Seattle, WA 98121, or to firstname.lastname@example.org
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A Comparison of Rate Control and Rhythm Control in Patients with Recurrent Persistent Atrial Fibrillation
Isabelle C. Van Gelder, M.D., Vincent E. Hagens, M.D., Hans A. Bosker, M.D., J. Herre Kingma, M.D., Otto Kamp, M.D., Tsjerk Kingma, M.Sc., Salah A. Said, M.D., Julius I. Darmanata, M.D., Alphons J.M. Timmermans, M.D., Jan G.P. Tijssen, Ph.D., Harry J.G.M. Crijns, M.D., for the Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation Study Group
Background Maintenance of sinus rhythm is the main therapeutic goal in patients with atrial fibrillation. However, recurrences of atrial fibrillation and side effects of antiarrhythmic drugs offset the benefits of sinus rhythm. We hypothesized that ventricular rate control is not inferior to the maintenance of sinus rhythm for the treatment of atrial fibrillation.
Methods We randomly assigned 522 patients who had persistent atrial fibrillation after a previous electrical cardioversion to receive treatment aimed at rate control or rhythm control. Patients in the rate-control group received oral anticoagulant drugs and rate-slowing medication. Patients in the rhythm-control group underwent serial cardioversions and received antiarrhythmic drugs and oral anticoagulant drugs. The end point was a composite of death from cardiovascular causes, heart failure, thromboembolic complications, bleeding, implantation of a pacemaker, and severe adverse effects of drugs.
Results After a mean (±SD) of 2.3±0.6 years, 39 percent of the 266 patients in the rhythm-control group had sinus rhythm, as compared with 10 percent of the 256 patients in the rate-control group. The primary end point occurred in 44 patients (17.2 percent) in the rate-control group and in 60 (22.6 percent) in the rhythm-control group. The 90 percent (two-sided) upper boundary of the absolute difference in the primary end point was 0.4 percent (the prespecified criterion for noninferiority was 10 percent or less). The distribution of the various components of the primary end point was similar in the rate-control and rhythm-control groups.
Conclusions Rate control is not inferior to rhythm control for the prevention of death and morbidity from cardiovascular causes and may be appropriate therapy in patients with a recurrence of persistent atrial fibrillation after electrical cardioversion.
From the Department of Cardiology (I.C.V.G., V.E.H., H.J.G.M.C.) and the Trial Coordination Center (T.K.), University Hospital, Groningen; Rijnstate Hospital, Arnhem (H.A.B.); St. Antonius Hospital, Nieuwegein (J.H.K.); Free University Medical Center, Amsterdam (O.K.); Hospital Midden-Twente, Hengelo (S.A.S.); Twenteborg Hospital, Almelo (J.I.D.); Medisch Spectrum Twente, Enschede (A.J.M.T.); and Academic Medical Center, Amsterdam (J.G.P.T.) — all in the Netherlands.
Address reprint requests to Dr. Van Gelder at the Department of Cardiology, Thoraxcenter, University Hospital Groningen, P.O. Box 30.001, 9700 RB Groningen, the Netherlands, or at email@example.com
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