The relationship between cardiac surgeon experience and average patient risk profile: CA and NY statewide analysis

Background: It is unknown how high and low-risk cases are distributed among cardiac surgeons of different experience levels. The purpose of this study was to determine if high and low-risk coronary artery bypass grafting (CABG) cases are distributed among surgeons in such a way that would optimize outcomes in light of recent studies that show mid-career surgeons may obtain better patient outcomes on more complex cases.

Methods: We performed a cross-sectional study using aggregated New York (NY) and California (CA) statewide surgeon-level outcome data, including 336 cardiac surgeons who performed 43,604 CABGs. The surgeon observed and expected mortality rates (OMR and EMR) were collected and the number of years-in-practice was determined by searching for surgeon training history on online registries. Loess and linear regression models were used to characterize the relationship between surgeon EMR and surgeon years-in-practice.

Results: The median number of surgeon years-in-practice was 20 (interquartile range [IQR] 11-28) with a median annual case volume of 46 (IQR 19, 70.25). The median surgeon observed to expected mortality (O:E) ratio was 0.87 (IQR 0.19-1.4). Median EMR for CA surgeons was 2.42% and 1.44% for NY surgeons. Linear regression models showed EMR was similar across years in practice. Regression models also showed surgeon O:E ratios were similar across years-in-practice.

Conclusion: High and low-risk CABG cases are relatively equally distributed among surgeons of differing experience levels. This equal distribution of high and low-risk cases does not reflect a triaging of more complex cases to more experienced surgeons, which prior research shows may optimize patient outcomes.