Background: Postoperative atrial fibrillation (POAF) remains a common complication after cardiac surgery. The ability to accurately identify patients at risk through previous risk scores is limited. This study aimed to evaluate the new HARMS2-AF risk score to predict POAF after coronary artery bypass grafting (CABG) surgery.

Methods: In this retrospective cohort study, we included 265 patients undergoing CABG surgery from 2022-2023. Data were obtained from the medical files of the patients and hospital records. Each patient was assigned a HARMS2-AF risk score. A univariate and multivariate regression analyses were done to analyze independent predictors of POAF.

Results: Of 265 patients, 49 had postoperative atrial fibrillation. HARMS2-AF score was significantly higher in patients with POAF. Age, sleep apnea,a left atrial diameter (LAd), and HARMS2-AF score were independently associated with POAF. A HARMS2-AF score ≥ 4.5 predicted POAF with 91% sensitivity and 64% specificity (AUC = 0.787, 95% CI = 0.731-0.842, P < .001).

Conclusion: The HARMS2-AF score is a strong predictor of atrial fibrillation (AF) development after isolated CABG surgery. It can be used as a novel stratification tool to estimate AF after cardiac surgery.