Amiodarone versus a β-blocker to prevent atrial fibrillation after cardiovascular surgery

Background Both amiodarone and β-blockers have been shown to decrease the incidence of atrial fibrillation after cardiovascular surgery. However, the superior agent has not been identified. Methods We performed a pilot study on 102 patients (68 men, mean age 65 ± 10 years, mean left ventricular ejection fraction 0.53 ± 0.12) undergoing cardiovascular surgery (94 coronary artery bypass grafting [CABG], 5 valvular surgery only, and 3 CABG + valvular surgery). The patients were randomized to receive amiodarone (1 g/d intravenously × 48 hours, then 400 mg/d orally until discharge) or propranolol (1 mg intravenously every 6 hours × 48 hours, then 20 mg orally four times a day until discharge). Atrial fibrillation was defined as lasting longer than 1 hour or resulting in hemodynamic compromise. Results The incidence of postoperative atrial fibrillation was 16.0% (8/50) in the amiodarone group and 32.7% (17/52) in the propranolol group (P = .05). The mean length of stay was 8.8 ± 3.5 days for amiodarone-treated patients and 8.4 ± 2.7 days for propranolol-treated patients (P not significant). Serious adverse events were uncommon and similar in each group. Conclusion Early intravenous amiodarone, followed by oral amiodarone, appears to be superior to propranolol in the prevention of postoperative atrial fibrillation. It is well tolerated and can be started at the time of surgery. However, the use of amiodarone did not result in a reduction in the length of hospital stay. (Am Heart J 2001;142:811-5.)