Early outcomes and predictors of in-hospital mortality after redo cardiac surgery: impact of combined procedures

Redo cardiac surgery is being performed more frequently as survival after primary cardiac operations continues to improve. However, repeat procedures are associated with higher perioperative risk, particularly when multiple procedures are performed during the same operation. We conducted a retrospective observational study of 114 patients who underwent redo cardiac surgery between January 2010 and December 2023. Patients were classified as isolated redo procedures ( n = 68) or combined redo procedures ( n = 46). Freedom from in-hospital death was evaluated using the Kaplan–Meier method. Compared with isolated redo surgery, patients undergoing combined procedures had longer cardiopulmonary bypass and aortic cross-clamp times, greater postoperative drainage, prolonged mechanical ventilation, and a longer hospital stay. In-hospital mortality was significantly higher in the combined redo group than in the isolated redo 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). Prolonged cardiopulmonary bypass time (≥ 180 min) (OR 2.4, 95% CI 1.1–5.3; p = 0.021) and NYHA functional class III–IV (OR 2.0, 95% CI 1.0–4.1; p = 0.048) were also identified as independent predictors of in-hospital mortality. Kaplan–Meier analysis showed a significantly higher risk of in-hospital death among patients undergoing combined redo procedures. Combined redo cardiac procedures were independently associated with increased in-hospital mortality. These findings highlight the importance of careful patient selection, meticulous operative planning, and appropriate perioperative risk stratification in this high-risk patient population.