What determines outcomes in multivalve reoperations? Effect of patient and surgical complexity

Patient characteristics, risks, and outcomes associated with reoperative multivalve cardiac surgery are poorly characterized. Effect of patient variables and surgical components of each reoperation were evaluated with regard to operative mortality. From January 2008 to January 2022, 2324 patients with previous cardiac surgery underwent 2352 reoperations involving repair or replacement of multiple cardiac valves at Cleveland Clinic. Mean age was 66 ± 14 years. Number of surgical components representing surgical complexity (valve procedures, aortic surgery, coronary artery bypass grafting, and atrial fibrillation procedures) ranged from 2 to 6. Random forest for imbalanced data was used to identify risk factors for operative mortality. Surgery was elective in 1327 (56%), urgent in 1006 (43%), and emergency in 19 (0.8%). First-time reoperations were performed in 1796 (76%) and 556 (24%) had 2 or more previous operations. Isolated multivalve operations comprised 54% (1265) of cases; 1087 incorporated additional surgical components. Two valves were operated on in 80% (1889) of cases, 3 in 20% (461), and 4 in 0.09% (2). Operative mortality was 4.2% (98 out of 2352), with 1.7% (12 out of 704) for elective, isolated multivalve reoperations. For each added surgical component, operative mortality incrementally increased, from 2.4% for 2 components (24 out of 1009) to 17% for ≥5 (5 out of 30). Predictors of operative mortality included coronary artery bypass grafting, surgical urgency, cardiac, renal dysfunction, peripheral artery disease, New York Heart Association functional class, and anemia. Elective, isolated reoperative multivalve surgery can be performed with low mortality. Surgical complexity coupled with key physiologic factors can be used to inform surgical risk and decision making.