Intravenous amiodarone for prevention of atrial fibrillation after coronary artery bypass grafting

Background. Atrial fibrillation occurs in 10% to 40% of patients who undergo coronary artery bypass grafting. This prospective study assesses the safety and efficacy of low-dose intravenous amiodarone in the prevention of atrial fibrillation after coronary artery bypass grafting. Methods. One hundred forty patients were randomly divided into two groups: an amiodarone group (n = 74) receiving intravenous amiodarone in a loading dose of 150 mg and maintenance dose of 0.4 mg·kg^-1·h^-1 for 3 days before and 5 days after operation and a control group (n = 76) receiving matching infusions of 5% glucose solution. Results. Atrial fibrillation occurred in 9 (12%) of the amiodarone group patients and in 26 (34%) of the control group patients during hospitalization (p < 0.01). The maximum ventricular rate during atrial fibrillation was significantly slower in the amiodarone group (107 ± 21) than in the control group (138 ± 24 beats per minute, p < 0.01). The duration of atrial fibrillation in the amiodarone group (1.1 ± 1.2 hours) was significantly shorter than that in the control group (3.2 ± 1.3 hours, p = 0.01). The two groups had no significant differences in incidence of major morbidity (8 of 74 versus 8 of 76 in amiodarone and control groups, respectively) or mortality (4 of 74 versus 5 of 76). However, the control group had significantly longer intensive care unit stays (132 ± 24 versus 111 ± 19 hours, p < 0.01). Conclusions. Perioperative low-dose intravenous amiodarone significantly reduces the incidence, ventricular rate, and duration of atrial fibrillation after coronary artery bypass grafting. Furthermore, low-dose intravenous amiodarone is well tolerated and does not increase the risk of intraoperative or postoperative complications. (C) 2000 by The Society of Thoracic Surgeons.