Amiodarone reduces the incidence of atrial fibrillation after coronary artery bypass grafting

The purpose of this study was to evaluate the safety and efficacy of postoperative administration of prophylactic amiodarone in the prevention of new-onset postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting. In this prospective study 157 patients were randomly divided into two groups: 77 patients (amiodarone group) received intravenous amiodarone in a dose of 10 mg/kg/d for postoperative 48 hours. On postoperative day 2 oral amiodarone was started with a dose of 600 mg/d for 5 days, 400 mg/d for the following 5 days, and 200 mg/d for 20 days, and 80 patients received placebo (control group). Preoperative patient characteristics and operative variables were similar in the two groups. Postoperative atrial fibrillation occurred in 8 patients (10.4%) receiving amiodarone and in 20 (25.0%) patients receiving placebo ( P = .017). Duration of atrial fibrillation was 12.8 ± 4.8 hours for the amiodarone group compared with 34.7 ± 28.7 hours for the control group ( P = .003). The maximum ventricular rate during atrial fibrillation was slower in the amiodarone group than in the control group (105.9 ± 19.1 beats per minute and 126.0 ± 18.5 beats per minute, respectively, P = .016). The two groups had a similar incidence of complication other than rhythm disturbances (20.8% vs 20.0%, P = .904). Amiodarone group patients had shorter hospital stays than that of control group patients (6.8 ± 1.7 days vs 7.8 ± 2.9 days, P = .014). The in-hospital mortality was not different between two groups (1.3% vs 3.8, P = .620). Postoperative intravenous amiodarone, followed by oral amiodarone, appears to be effective in the prevention of new-onset postoperative atrial fibrillation. It also reduces ventricular rate and duration of atrial fibrillation after coronary artery bypass grafting. It is well tolerated and decreases the length of hospital stay.