Sepsis Risk after On-pump vs Off-pump Coronary Artery Bypass Surgery: A MIMIC-IV Database Analysis

Objective This study aims to compare the differences in postoperative sepsis between patients treated with coronary artery bypass grafting (CABG) with and without cardiopulmonary bypass (CPB), and investigate the related risk factors. Methods 6509 patients treated with CABG from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database were categorized into on-pump and off-pump groups according to whether CPB was used. Binary logistic regression and Least Absolute Shrinkage and Selection Operator (LASSO) method was used to select factors associated with sepsis occurrence in all patients and in on-pump group. Multivariate Cox proportional hazards analysis was used to assess the association between selected variables and postoperative sepsis. Results In the Baseline Characteristics, the prevalence of sepsis was significantly higher in the on-pump group than in the off-pump group. Multivariate logistic regression analysis indicates CPB is a risk factor for sepsis (OR = 6.822, 95% CI 5.883–7.922, P < 0.001). In on-pump group, three variables were selected using the Lasso method: comorbid pneumonia, serum lactate level in 24 hours after ICU admission, and length of ICU stays. Multivariate Cox regression analysis suggested that serum lactate levels (HR = 1.096, 95% CI 1.038–1.157, p < 0.001) and comorbid pneumonia (HR = 1.221, 95% CI 1.091–1.367, p < 0.001) are independent risk factors for postoperative sepsis, apart from CPB. Conclusion CPB, high serum lactate levels and comorbid pneumonia are independent risk factors for postoperative sepsis in patients receiving CABG surgery.