Abstract
BACKGROUND: We hypothesized that body surface area (BSA)-weighted left ventricular ejection fraction (LVEF) (bLVEF) would represent a superior predictor of mortality in off-pump coronary artery bypass grafting (OPCABG) patients than standard predictors. LVEF is associated with worse outcomes upon OPCABG, while referring left ventricular measurements to BSA should improve predictability. METHODS: The bLVEF was calculated by multiplying the LVEF by the BSA. The primary endpoint was all-cause mortality within 30 days of hospitalization, while secondary endpoints included major postoperative complications. RESULTS: A total of 7927 patients from five leading cardiac centers participating in the Chinese Cardiac Surgery Registry were included in the final analysis, of which 7093 (89.48%) had normal LVEF, 639 (8.06%) presented heart failure with mid-range ejection fraction (HFmrEF), and 195 (2.46%) exhibited heart failure with reduced ejection fraction (HFrEF). The average bLVEF in the cohort was 109.63 ± 18.16. Both the mortality (odds ratio (OR) 0.97) and secondary endpoints (OR 0.97) followed a similar trend with increasing bLVEF, indicating that bLVEF is a more reliable predictor of adverse outcomes. The individual components of bLVEF, including BSA (area under the curve (AUC) 0.63) and LVEF (AUC 0.64), made minor contributions to mortality risk with relatively low AUC values. However, these components were less impactful than bLVEF (AUC 0.70). Notably, patients with a bLVEF less than 85 had an increased mortality risk relative to those whose bLVEF was 85 or higher (adjusted OR 4.65 (95% confidence interval (CI): 3.81-5.83; p < 0.01)). CONCLUSION: The bLVEF serves as a key predictor of mortality in OPCABG patients, effectively eliminating BSA-related bias and demonstrating a strong capacity to predict mortality. CLINICAL TRIAL REGISTRATION: NCT02400125, https://www.clinicaltrials.gov/study/NCT02400125.