Treatment of Resistant Atrial Fibrillation

BACKGROUND: Chronic atrial fibrillation (AF) is a common arrhythmia with significant morbidity and mortality. Maintenance of normal sinus rhythm (NSR) can be achieved with antiarrhythmic drug therapy. The antiarrhythmic effects of amiodarone hydrochloride and flecainide acetate in patients with resistant chronic AF have been investigated separately in several small studies. This investigation compared amiodarone to flecainide in maintaining NSR in patients with resistant chronic AF. METHODS: Studies using amiodarone or flecainide in the treatment of patients with chronic AF refractory to class I antiarrhythmic drugs or sotalol hydrochloride were identified. The results of six trials of amiodarone (200 to 400 mg/d, 315 patients) and two trials of flecainide (200 to 300 mg/d, 163 patients) were aggregated using meta-analytic techniques. The percentages of patients taking amiodarone or flecainide and remaining in NSR at 3 and 12 months were compared relative to results for quinidine, which were acquired from a meta-analysis of quinidine used as first-line therapy for AF. RESULTS: After 3 and 12 months of treatment with amiodarone, 217 (72.6%) of 299 patients and 64 (59.8%) of 107 patients, respectively, remained in NSR. These percentages were significantly greater (P < .0001) than those for quinidine (70% and 50%, respectively). For flecainide, the percentage of patients remaining in NSR was significantly lower (P < .0001) than for quinidine: 79 (48.5%) and 56 (34%) of 163 patients, respectively. The aggregated percentages of patients requiring withdrawal of amiodarone and flecainide were similar: 9.5% and 8.6%, respectively. Mortality and proarrhythmia could not be assessed. CONCLUSION: This analysis suggests that low-dose amiodarone is more efficacious and equally well tolerated when compared with flecainide in the management of chronic, drug-resistant AF.