Prophylactic oral amiodarone compared with placebo for prevention of atrial fibrillation after coronary artery bypass surgery

Background Postoperative atrial fibrillation occurs in 20% to 40% of patients undergoing coronary artery bypass grafting (CABG) and contributes to delayed recovery, increased length of stay, and increased hospital cost. Measures at preventing postoperative atrial fibrillation have had mixed results. We report a double-blind trial comparing oral amiodarone with placebo for the prevention of atrial fibrillation after CABG. Methods And Results All patients undergoing CABG were considered eligible. Exclusion criteria included bradycardia (<50 beats/min), prior Atrial fibrillation, concurrent therapy with antiarrhythmic drugs, or concomitant valve surgery. Patients were given 2 g of amiodarone (73 patients) or placebo (70 patients) in divided doses 1 to 4 days before surgery and 400 mg daily for 7 days postoperatively. Atrial fibrillation occurred in 24.7% (18 of 43) of patients receiving amiodarone and 32.8% (23 of 70) of patients receiving placebo (P = .30). Heart rate at onset of atrial fibrillation was 133.4 ± 26.6 beats/min for amiodarone compared with 152.9 ± 31.6 beats/min for placebo ( P = .04). Duration of atrial fibrillation was 10.2 ± 8.1 hours for amiodarone compared with 16.2 ± 27.5 hours for placebo (P = .67). Patients receiving both β-blockade and amiodarone had a 16.7% incidence of atrial fibrillation compared with 31.9% in the remaining patients (P = .10). Atrial fibrillation was associated with an increased cost of $7011 compared with those who remained in sinus rhythm ($23,869 ± $20,894 vs $16,857 ± $5401 in sinus rhythm). Hospital cost of those taking amiodarone was $18,895 ± $13,267 compared with $18,839 ± $11,537.18 for placebo (P = .42). Conclusion Postoperative CABG atrial fibrillation is associated with prolonged hospital stay and increased cost. Prophylactic oral amiodarone did not statistically alter the incidence or duration of atrial fibrillation after CABG, although favorable trends were noted. Hospital cost was not affected by therapy with amiodarone. (Am Heart J 1999;138:144-50.)