Perioperative intravenous amiodarone does not reduce the burden of atrial fibrillation in patients undergoing cardiac valvular surgery.

Background: Atrial fibrillation is a common complication after cardiac surgery. Postoperative atrial fibrillation is associated with increased risks of morbidity and mortality, and, therefore, preventive strategies using oral amiodarone have been developed but are often unpractical. Intravenous amiodarone administered after the induction of anesthesia and continued postoperatively for 48 h could represent an effective strategy to prevent postoperative atrial fibrillation in patients undergoing cardiac valvular surgery.

Methods: Single-center, double-blinded, double-dummy, randomized controlled trial in patients undergoing valvular surgery. Patients received either an intravenous loading dose of 300 mg of amiodarone or placebo in the operating room, followed by a perfusion of 15 mg . kg(-1) . 24 h(-1) for 2 days. The primary endpoint was the development of atrial fibrillation occurring at any time within the postoperative period.

Results: One hundred twenty patients were randomly assigned (mean age was 65 +/- 11 yr). Overall atrial fibrillation occurred more frequently in the perioperative intravenous amiodarone group compared with the placebo group (59.3 vs. 40.0%; P = 0.035). Four preoperative factors were found to be independently associated with a higher risk of developing postoperative atrial fibrillation: older age (P = 0.0003), recent myocardial infarction (<6 months; P = 0.026), preoperative angina (P = 0.0326), and use of a calcium channel blocker preoperatively (P = 0.0078) when controlling for groups.

Conclusion: In patients undergoing cardiac valvular surgery, a strategy using intravenous amiodarone for 48 h is not efficacious in reducing the risk of atrial fibrillation during cardiac valvular surgery.