Short-duration oral amiodarone for prevention of atrial fibrillation post heart surgery

Atrial fibrillation occurs in 20% to 40% of patients post cardiac surgery. Prophylactic amiodarone decreases the incidence of atrial fibrillation, especially in those not taking β-blockers. Studies, however, vary in dosage, duration of treatment, and route of administration. Limited studies evaluating short duration use of oral amiodarone show conflicting results. We hypothesize that an order set for use of short duration, oral amiodarone started the night before surgery and continued for 4 to 6 days will decrease atrial fibrillation after heart surgery.

The Society of Thoracic Surgeons database was used to identify 471 patients who received amiodarone per order set and 151 patients that did not receive amiodarone. The amiodarone order set included amiodarone 600 mg the night before surgery and 400mg twice daily for 4 to 6 days post heart surgery. After propensity matching, 112 patients remained in each group. We compared outcomes for the 2 groups as a case-controlled, retrospective, study.

Atrial fibrillation occurred in 43% (48 of 112) of the patients that did not receive amiodarone vs 23% (26 of 112) receiving prophylactic amiodarone (P=<.001). There was no increased incidence of hemodynamic, pulmonary, or other adverse outcomes observed between the 2 groups.

This practical order set for, short duration, oral amiodarone, with or without adjunct β-blocker therapy started the night before heart surgery and continued for up to six days post surgery, appears to be a safe and effective treatment for reducing the incidence of atrial fibrillation following heart surgery.