Control of rate versus rhythm in rheumatic atrial fibrillation: a randomized study.

BACKGROUND: Patients with rheumatic heart disease and atrial fibrillation incur significant morbidity and mortality. It is not known which approach, rate control or maintenance of sinus rhythm might be most appropriate. The present study was undertaken to compare the strategy of ventricular rate control versus maintenance of sinus rhythm in rheumatic atrial fibrillation, and to evaluate the role of amiodarone in this patient population. METHODS AND RESULTS: We prospectively studied 144 patients with chronic rheumatic atrial fibrillation in a double-blind protocol-rhythm control (group I: 48 patients each with amiodarone -group Ia; and placebo -group Ib) and compared the effects with the ventricular rate control (group II) by diltiazem (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 was 4.7+/-0.6 cm, atrial fibrillation duration was 6.1+/-5.4 years, and 72.9% patients had undergone valvular interventions. At 1 year, 45 patients with sinus rhythm in group I compared to 48 patients in group II demonstrated significant increase in exercise to sinus rhythm time, had improvement in functional class and quality of life score. There was no difference in hospitalization rates, systemic bleeds or incidence of thromboembolism. Five patients died in group II but none in group I (p=0.02). In group I, 73/87 (83.9%) patients converted, and 45/86 (52.3%) patients maintained sinus rhythm at 1 year. Conversion rates were 38/43 (88.4%) with amiodarone versus 34/44 (77.3%) with placebo (p=0.49): corresponding rate for maintaining sinus rhythm was 29/42 (69.1%) versus 16/44 (36.4%), p=0.008 respectively. CONCLUSIONS: Maintenance of sinus rhythm appeared to be superior to ventricular rate control in patients with rheumatic atrial fibrillation in terms of an effect on mortality and morbidity. Sinus rhythm could be restored in the majority and amiodarone was superior to placebo in this regard.