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

Background Both amiodarone and beta -blockers have been shown to decrease t he 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) undergoin g cardiovascular surgery (94 coronary artery bypass grafting [CABG], 5 valv ular surgery only, and 3 CABG + valvular surgery). The patients were random ized to receive amiodarone (1 g/d intravenously x 48 hours, then 400 mg/d o rally until discharge) or propranolol (1 mg intravenously every 6 hours x 4 8 hours, then 20 mg orally four times a day until discharge). Atria] fibril lation was defined as lasting longer than 1 hour or resulting in hemodynami c 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 = .0 5). The mean length of stay was 8.8 +/- 3.5 days for amiodarone-treated pat ients and 8.4 +/- 2.7 days for propranolol-treated patients (P not signific ant). Serious adverse events were uncommon and similar in each group. Conclusion Early intravenous amiodarone, followed by oral amiodarone, appea rs to be superior to propranolol in the prevention of postoperative atrial fibrillation. ft is well tolerated and can be started at the time of surger y. However, the use of amiodarone did not result in a reduction in the leng th of hospital stay.