Methods: Between January 2010 and July 2013, a total of 478 patients (305 males, 173 females; mean age 62.1 years; range 40 to 83 years) who underwent coronary artery bypass grafting in our clinic were enrolled in the study. Data were obtained from the medical files of the patients and hospital records. All patients were monitored in the intensive care unit after surgery. Atrial fibrillation lasting more than 30 seconds in irregular rhythm without P waves on telemetry was classified as postoperative atrial fibrillation. All patients were evaluated using CHADS2 and CHA2DS2-VASc scoring systems.

Results: Of 478 patients, 102 had postoperative atrial fibrillation. CHADS2 and CHA2DS2-VASc scores were statistically significantly higher in patients with postoperative atrial fibrillation than others (2.1±0.8 vs 1.1±0.8, p<0.001 and 4.3±1.1 vs 2.2±1.1, p<0.001). Age, left atrial diameter, left ventricular ejection fraction, and CHA2DS2-VASc scores were independently associated with postoperative atrial fibrillation. A CHA2DS2-VASc score of ≥2 predicted postoperative AF with %96.3 sensitivity and %74.6 specificity (AUC=0.906, 95% CI=0.875-0.938, p<0.001).

Conclusion: The CHA2DS2-VASc score is a strong predictor of atrial fibrillation development after isolated coronary artery bypass grafting surgery. Therefore, the CHA2DS2-VASc scoring system can be used as a stratification tool to estimate atrial fibrillation after coronary artery bypass grafting.