Background: Postoperative atrial fibrillation (AF) is a common arrhythmia that occurs after coronary artery bypass grafting (CABG). New surgical techniques, particularly off-pump coronary artery bypass (OPCAB), are thought to be less invasive and results in fewer complications, i.e. AF, but available data are inconsistent. The aim of this study is to present the incidence and risk factors of AF in patients operated on with or without cardiopulmonary bypass.

Methods: We studied 1836 consecutive patients with stable coronary artery disease who were operated on with (CABG) or without (OPCAB) cardiopulmonary bypass. The patients were monitored using a continuous electrocardiogram monitoring system until the sixth postoperative day.

Results: Atrial fibrillation occurred in 18.3% and 19.3% of CABG and OPCAB patients, respectively (p = 0.3). The peak incidence of arrhythmia was observed between the second and third postoperative day in both CABG and OPCAB patients (36% and 41%, respectively). Patient’s age and history of hypertension were significant predictors of postoperative AF (OR 1.38, 95% CI 1.01–1.76, p = 0.0002; and OR 1.38, 95% CI 1.01–1.76, p = 0.008, respectively). Patients who developed AF vs. without AF had significantly higher rates of complications such as death (3.1% vs. 1.2%, p = 0.01), reoperation (5.2% vs. 2.8%, p = 0.02), and the need to utilize intra-aortic balloon pump (IABP) (6.8% vs. 3.4%, p = 0.002). Use of IABP and reoperation were significant perioperative predictors of the arrhythmia (OR 2.1, 95% CI 1.27–3.4, p = 0.003; and OR 1.9, 95% CI 1.09–3.30, p = 0.02, respectively). AF was also associated with a prolonged stay in an intensive care unit (72.5 ± 78.8 for patients with AF vs. 34.6 ± 25.2 for patients with sinus rhythm, p = 0.000001).

Conclusions: In patients undergoing CABG, postoperative AF is a common arrhythmia independent of the type of surgical procedure.