Control of Heart Rate Versus Rhythm in Rheumatic Atrial Fibrillation: A Randomized Study

Abstract

Background: Patients with rheumatic heart disease with atrial fibrillation incur significant morbidity and mortality. Which approach, ventricular rate control or maintenance of sinus rhythm, in this setting might be superior is not known. The role of amiodarone in this patient population for maintaining sinus rhythm has not been evaluated. Methods and Results: We prospectively studied 144 patients with chronic rheumatic atrial fibrillation in a double-blind protocol in which rhythm control (group I), comprising 48 patients each with amiodarone (group Ia) and placebo (group Ib), were compared with each other and with patients in a ventricular rate control group (group II) in which the effects by diltiazem were determined (n = 48, open-label). Direct current cardioversion was attempted in group I. The mean age of the study population was 38.6 ± 10.3 years, left atrial size, 4.7 ±0.6 cm; atrial fibrillation duration, 6.1 ± 5.4 years; and 72.9% had valvular interventions performed. At 1 year, 45 patients with sinus rhythm in group I compared with 48 in group II demonstrated an increase in exercise time (2.6 ± 1.9 vs. 0.6 ± 2.5 min, P = .001), improvement in New York Heart Association class of 1 or more ( P = .002), and improvement in the quality-of-life score of one or greater ( P = 0.01) with no difference in hospitalizations, systemic bleeds, or thromboembolism. Five patients died in group II; none died in group I ( P =.02). In group I, 73 of 87 (83.9%) patients converted to sinus rhythm and 45 of 86 (52.3%) patients maintained the rhythm at 1 year. Conversion rates were 38 of 43 (88.4%) with amiodarone versus 34 of 44 (77.3%) with placebo ( P = .49); the corresponding rate for maintaining sinus rhythm was 29 of 42 (69.1%) versus 16 of 44 (36.4%) ( P = .008). A larger number of electrical cardioversions were required in the placebo group (2.1 vs. 1.4, P = .011). Conclusions: Maintenance of sinus rhythm is superior to ventricular rate control in patients with rheumatic atrial fibrillation with respect to effects on exercise capacity, quality of life, morbidity, and possibly mortality. Sinus rhythm could be restored in most patients, and amiodarone was superior to placebo in the restoration and maintenance of sinus rhythm.