Impact of Surgical Experience on Operative Mortality After Reoperative Cardiac Surgery

Background: Learning curves and skill attrition with aging have been reported to impair outcomes in select surgical subspecialties, but their role in complex cardiac surgery remains unknown. Methods: From 1986 to 2019, 2314 patients underwent reoperative cardiac surgery: coronary artery bypass grafting (n = 543), valve (n = 1527), or combined coronary artery bypass grafting and valve (n = 244). Thirty-four different surgeons in practice between 1 and 39 years were included. Standardized mortality ratio (observed-to-expected) was determined for all surgeons in each post-training year of experience. Results: Risk-adjusted cumulative sum change-point analysis was used to define five distinct career phases: 0 to 4 years, 5 to 8 years, 9 to 17 years, 18 to 28 years, and 29 to 39 years. With 5 to 8 years and 18 to 28 years of experience, standardized mortality ratio was near unity (0.95 and 1.05, respectively) and lowest with 9 to 17 years of experience (0.78, P = .03). In the youngest experience group (0 to 4 years), observed and expected mortality were both highest, and standardized mortality ratio was elevated at 1.29, which approached statistical significance (P = .059). In the oldest experience group (29 to 39 years), expected mortality was low compared with most other groups but observed mortality increased, yielding a significantly elevated standardized mortality ratio at 1.53 (P = .032). Conclusions: Standardized mortality ratios with reoperative cardiac surgery were highest early and late in a surgeon's career and lowest in mid career. As surgeons gain experience, outcomes improve through the first two career decades, then stabilize in the third decade before declining in the fourth decade.