Nonlinear association and threshold effect between preoperative estimated pulse wave velocity and postoperative atrial fibrillation after coronary artery bypass grafting

Background: Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting (CABG), yet reliable preoperative risk markers remain limited. Estimated pulse wave velocity (ePWV), a simple noninvasive indicator of arterial stiffness, may enhance risk stratification; however, its association with POAF has not been fully elucidated. This study aimed to investigate the nonlinear association and potential threshold effect between preoperative ePWV and POAF in patients undergoing CABG. Methods: This single-center retrospective cohort study included 8,570 patients who underwent CABG between 2021 and 2022 at Beijing Anzhen Hospital. ePWV was calculated using age and mean blood pressure. Logistic regression, restricted cubic spline (RCS) modeling, and two-piecewise linear regression were used to evaluate the association and potential threshold effect between ePWV and POAF. Predictive performance was evaluated using receiver operating characteristic (ROC) analysis. Results: POAF occurred in 7.9% of patients. Higher ePWV was independently associated with POAF [adjusted odds ratio (OR): 1.15, 95% confidence interval (CI): 1.09-1.21; P