Preventing Atrial Fibrillation after Cardiac Surgery — Metoprolol vs. Amiodarone

Atrial fibrillation (AF) occurs relatively often after cardiac surgery and has a substantial effect on morbidity. Current guidelines (J Am Coll Cardiol 2006; 48:e149) recommend β-blockers as first-line agents for preventing AF, but many physicians prescribe amiodarone (an antiarrhythmic). In this Finnish trial, 316 hemodynamically stable patients were randomized to 48 hours of intravenous metoprolol or amiodarone (initiated 15–21 hours after surgery).

During the 48-hour follow-up, AF occurred in 24% of patients who received metoprolol and in 25% who received amiodarone. Study medication was discontinued more often among metoprolol patients (14% vs. 4%), usually because of hypotension.