Comparative effectiveness of pharmacotherapies for prevention of atrial fibrillation following coronary artery bypass surgery.

Risk of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is high, yet the effectiveness of guideline-recommended preoperative prophylaxis in clinical practice remains uncertain. We determined the utilization and variation of preoperative AF prevention and assessed the comparative effectiveness of alternative drugs using the Society of Thoracic Surgeons multicenter Contemporary Analysis of Perioperative Cardiovascular Surgical Care (CAPS-Care) registry. Among 2,177 patients who underwent high-risk CABG and/or valve surgery, the mean age was 71 ± 9, 66% were men, 26% had chronic lung disease, and 21% had cerebrovascular disease. Overall use of AF prophylaxis was 84% and varied across sites (range 52% to 100%). The most common preventive agents were beta blockers (72%), followed by calcium antagonists (17%). Postoperatively, 30% (n = 646) developed AF at a median of 2 (25th to 75th percentiles: 1 to 3) days after surgery. Increasing age, height, white race, body mass index >35, New York Heart Association class IV heart failure, preoperative dialysis, and concomitant aortic valve replacement were associated with greater odds of postoperative AF (p <0.05 for all). Preoperative amiodarone use was associated with a trend to reduction of postoperative AF (26%, adjusted odds ratio 0.72 [95% confidence interval 0.51 to 1.00], p = 0.052). After adjustment, the odds of postoperative AF were not statistically different across agents. In conclusion, use of AF prophylaxis before surgery varied significantly. In this high-risk population, we were unable to demonstrate that any of the commonly used preventive agents were associated with lower rates of AF compared with alternatives or no treatment.