Incidence, Timing, and Clinical Outcomes of Postoperative Atrial Fibrillation After On-Pump Versus Off-Pump Coronary Artery Bypass Grafting

Background:Postoperative atrial fibrillation (POAF) is common after coronary artery bypass grafting (CABG); however, whether POAF characteristics and follow-up outcomes differ between off-pump and conventional on-pump CABG remains incompletely defined. Clinically applicable tools for individualized postoperative mortality risk stratification after CABG are also required. Thus, this study aimed to compare the incidence and timing of POAF onset, perioperative course, and follow-up outcomes between on-pump and off-pump CABG, and to develop a mortality prediction nomogram.Methods:This retrospective cohort included 159 patients undergoing on-pump CABG and 518 undergoing off-pump CABG. In-hospital outcomes and follow-up events were compared between groups, and overall survival was assessed using Kaplan–Meier analysis. Predictors were selected using least absolute shrinkage and selection operator (LASSO)-penalized Cox regression and then entered into a multivariable Cox proportional hazards regression model for nomogram construction.Results:On-pump CABG was associated with longer operative time, more frequent blood product transfusion, and longer hospital stay (IQR 15 (12.5, 18) vs. 13 (10, 15) days; p < 0.001). The incidence of POAF was similar between groups (23.27% vs. 21.62%; p = 0.661), but onset occurred later after on-pump CABG (IQR 2 (2, 4) vs. 2 (1, 3) days; p = 0.014). Long-term outcomes did not differ significantly between groups, and disease-free survival was comparable (log-rank p = 0.659). In the multivariable Cox analysis, age (hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.05–1.14), duration of mechanical ventilation (HR 1.02, 95% CI 1.01–1.04), and prior cerebrovascular accident (CVA) (HR 2.54, 95% CI 1.28–5.03) independently predicted mortality (all p < 0.05). A Cox-based nomogram was developed to estimate individualized 1-, 3-, and 5-year survival.Conclusions:In this cohort, on-pump and off-pump CABG had similar POAF incidence and comparable follow-up outcomes, supporting individualized operative strategy selection based on patient and procedural considerations. A Cox-based nomogram may aid postoperative mortality risk stratification, although external validation is required before broader clinical application.