Pharmacological conversion of recent atrial fibrillation: a randomized, placebo-controlled study of three antiarrhythmic drugs

Abstract

In this study, we randomly compared single oral doses of flecainide, amiodarone and propafenone versus placebo for the conversion of recent atrial fibrillation (AF) (within 48 hours). This is a randomized prospective, placebo-controlled single-blind study that included 160 consecutive patients with recent AF who were randomly assigned to single oral doses of flecainide (3 mg/kg of weight, n=40), amiodarone (30 mg/kg weight, n=40), propafenone (8.5 mg/kg of weight, n=40) or placebo (n=40). The primary end-point was conversion rate at 24 hours after the drug intake. The association between antiarrhythmic use and conversion rate was tested with multiple logistic regressions. The primary end-point was achieved in 87.5% of patients with flecainide, 85% of patients with amiodarone, 85% of patients with propafenone and 17.5% of patients with placebo (p<0.001 compared with placebo for all 3 drugs). Conversion rate within 3 hours after drug intake was greater with propafenone (57.5%) or flecainide (45%) compared with amiodarone (0%) or placebo (10%). Between 6 and 24 hours, significantly more patients were converted to sinus rhythm with amiodarone than with flecainide or propafenone. The use of antiarrhythmic drugs was a significant predictor of conversion to sinus rhythm compared to placebo (adjusted OR=19.53, 95% CI 3.14-121.55, p<0.001). No serious side effect occurred. In patients with recent-onset AF, oral flecainide, amiodarone or propafenone are superior to placebo in restoring sinus rhythm within the 24-hour period following the drug intake.