Rate versus Rhythm Control Pharmacotherapy for Atrial Fibrillation: Where are We in 2008?

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disturbance encountered by physicians. The management of AF is focused on control of heart rate, correction of rhythm disturbance, and risk-determined prophylaxis of thromboembolism. The goals of AF therapy are, as with other serious disorders, to reduce mortality (if possible) and mortality (improve quality of life, [QOL]). To this end, several large studies have examined rhythm-control versus rate-control strategies. Although a survival advantage to using rhythm control with currently available antiarrhythmic drugs has not been proven, neither has there been a significant excess risk versus rate control. Therefore, using our current therapies, the results have not supported rate control or rhythm control as being a preferable first-line therapy for AF as regards survival; importantly, neither do they disprove the hypothesis that maintenance of sinus rhythm is preferable to the continuation of AF, particularly if rate control fails to restore adequate QOL. Many post-hoc analyses and substudies have assessed QOL, functional status, and exercise tolerance, with the majority demonstrating important benefits associated with achievement of rhythm control. This review examines rate and rhythm control options, the clinical outcomes of several important AF trials, discusses the limitations in applying the major morbidity/mortality findings to everyday clinical practice, and summarizes the lessons learned.