Abstract
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<0.001]. A significant nonlinear relationship was observed, with an inflection point at 11.4 m/s. Below this threshold, each 1 m/s increase in ePWV was associated with a 27% higher risk of POAF, whereas no significant association was observed at ePWV values ≥11.4 m/s. The area under the curve (AUC) for ePWV was 0.583, and the optimal cutoff of 9.62 meters per second yielded a negative predictive value of 94.6%. CONCLUSIONS: ePWV shows an independent and nonlinear association with POAF after CABG, with identifiable thresholds that may inform preoperative risk stratification. As a simple and noninvasive measure of arterial stiffness, ePWV may assist in identifying patients at elevated risk of POAF. Validation in multicenter prospective cohorts is warranted to establish its broader clinical utility.