TREATMENT OF RESISTANT ATRIAL-FIBRILLATION - A METAANALYSIS COMPARINGAMIODARONE AND FLECAINIDE

Background: Chronic atrial fibrillation (AF) is a common arrhythmia wi th significant morbidity and mortality. Maintenance of normal sinus rh ythm (NSR) can be achieved with antiarrhythmic drug therapy. The antia rrhythmic effects of amiodarone hydrochloride and flecainide acetate i n patients with resistant chronic AF have been investigated separately in several small studies. This investigation compared amiodarone to f lecainide in maintaining NSR in patients with resistant chronic AF. Me thods: Studies using amiodarone or flecainide in the treatment of pati ents with chronic AF refractory to class I antiarrhythmic drugs or sot alol hydrochloride were identified. The results of six trials of amiod arone (200 to 400 mg/d, 315 patients) and two trials of flecainide (20 0 to 300 mg/d, 163 patients) were aggregated using meta-analytic techn iques. 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 AE. Results: After 3 and 12 months of t reatment with amiodarone, 217 (72.6%) of 299 patients and 64 (59.8%) o f 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 i n NSR was significantly lower (P<.0001) than for quinidine: 79 (48.5%) and 56 (34%) of 163 patients, respectively. The aggregated percentage s of patients requiring withdrawal of amiodarone and flecainide were s imilar: 9.5% and 8.6%, respectively. Mortality and proarrhythmia could not be assessed. Conclusion: This analysis suggests that low-dose ami odarone is more efficacious and equally well tolerated when compared w ith flecainide in the management of chronic, drug-resistant AF.