Early Outcomes and Predictors of In-Hospital Mortality After Redo Cardiac Surgery: Impact of Combined Procedures

Background: Redo cardiac surgery is being performed more frequently as survival after initial cardiac operations continues to improve. However, repeat procedures remain technically demanding and carry higher perioperative risk, particularly when additional combined interventions are required. Methods: We conducted a retrospective observational study including 114 patients who underwent redo cardiac surgery between January 2010 and December 2023. Patients were divided into isolated redo procedures (n=68) and combined redo procedures (n=46). The primary outcome was in-hospital mortality, and early survival was assessed using the Kaplan–Meier method. Results: Compared with isolated redo surgery, combined redo procedures were associated with longer cardiopulmonary bypass and aortic cross-clamp times, increased postoperative drainage, longer ventilation duration, and a longer hospital stay. In-hospital mortality was significantly higher in the combined group (32.6% vs. 13.2%). On multivariable analysis, combined redo surgery remained an independent predictor of in-hospital mortality (OR 3.1, 95% CI 1.4–6.9; p=0.004). Mortality was also associated with cardiopulmonary bypass time ≥180 minutes (OR 2.4, 95% CI 1.1–5.3; p=0.021) and poorer functional status (NYHA class III–IV) (OR 2.0, 95% CI 1.0–4.1; p=0.048). Kaplan–Meier analysis demonstrated reduced early survival after combined redo surgery. Conclusions: Combined procedures during redo cardiac surgery are associated with higher early mortality and lower early survival, underscoring the importance of careful patient selection and preoperative risk stratification.