Oral amiodarone for prevention of atrial fibrillation after open heart surgery, the Atrial Fibrillation Suppression Trial (AFIST): a randomised placebo-controlled trial

Background beta -blockers and amiodarone reduce the frequency of atrial fib rillation after open-heart surgery but the effectiveness of oral amiodarone in older patients already receiving beta -blockers is unknown. We have ass essed the efficacy of oral amiodarone in preventing atrial fibrillation in patients aged 60 years or older undergoing open-heart surgery. Methods We did a randomised, double-blind placebo-controlled trial in which patients undergoing open-heart surgery (n=220, average age 73 years) recei ved amiodarone (n=120) or placebo (n=100). Patients enrolled less than 5 da ys before surgery received 6 g of amiodarone or placebo over 6 days beginni ng on preoperative day 1. Patients enrolled at least 5 days before surgery received 7 g over 10 days beginning on preoperative day 5. Findings Patients on amiodarone had a lower frequency of any atrial fibrill ation (22.5% vs 38.0%: p=0.01; absolute difference 15.5% [95% CI 3.4-27.6%] ), and there were significant differences in favour of the active drug for symptomatic atrial fibrillation (4.2% vs 18.0%. p=0.001), cerebrovascular a ccident (1.7% vs 7.0%, p=0.04), and postoperative ventricular tachycardia ( 1.7% vs 7.0%, p=0.04). beta -blocker use (87.5% amiodarone vs 91.0% placebo ), nausea (26.7% vs 16.0%), 30-day mortality (3.3% vs 4.0%), symptomatic br adycardia (7.5% vs 7.0%), and hypotension (14.2% vs 10.0%) were similar. Interpretation Oral amiodarone prophylaxis in combination with beta -blocke rs prevents atrial fibrillation and symptomatic fibrillation and reduces th e risk of cerebrovascular accidents and ventricular tachycardia.