Objective To test the hypothesis that perioperative OMEGA-3 polyunsaturated fatty acid infusion would reduce the incidence of postoperative atrial fibrillation in patients after coronary artery bypass grafting as assessed by an implantable continuous cardiac monitor.

Design Prospective, randomized, double-blind, placebo-controlled study.

Setting Tertiary cardiothoracic referral center.

Participants Thirty-nine patients with coronary artery disease who underwent surgery with cardiopulmonary bypass.

Interventions Patients were assigned randomly to receive either OMEGA-3 polyunsaturated fatty acids (200 mg/kg/day starting before anesthesia induction for 24 hours followed by 100 mg/kg/day for 7 days) or placebo. The primary outcome was freedom from atrial fibrillation at 2-year follow-up. Reveal^®cardiac monitor was implanted subcutaneously in all patients. Data from the cardiac monitor were collected on the 10th day and 3, 6, 12, and 24 months postoperatively. Measurement and Main Results Postoperative atrial fibrillation developed in 4 (19%) patients in the control group and in 5 (27.8%) patients in the study group at 10-day follow-up (p = 0.88). At 2-year follow-up, 5 (27.8%) patients in the control group and 6 (35.3%) patients in the study group had atrial fibrillation (p = 0.9). Atrial fibrillation duration predicted risk of cardiovascular hospitalization at the 2-year follow-up (regression coefficient estimate = 0.24, standard error 0.02, p<0.0001; R²= 0.74).

Conclusions Infusion of OMEGA-3 polyunsaturated fatty acids failed to prevent the occurrence of atrial fibrillation in 2 years after coronary artery bypass grafting surgery. The cumulative atrial fibrillation duration registered by the continuous cardiac monitor at the 2-year follow-up was a significant predictor of an adverse outcome.