Association between Body Mass Index and Acute Kidney Injury in Patients who Underwent Coronary Revascularization: A Retrospective Cohort Study from the MIMIC-IV Database.

Aim    Acute kidney injury (AKI) remains a common complication of coronary artery revascularization surgery and is associated with adverse outcomes in critically ill surgical patients. Body mass index (BMI) is associated with various diseases. This study aimed to evaluate the association between BMI and the risk of AKI in patients undergoing coronary artery revascularization surgery.Material and methods    In this retrospective cohort study, data were extracted from the Medical Information Mart for Intensive Care (MIMIC) - IV database from 2008 to 2019 for patients undergoing coronary artery revascularization surgery. The outcome was the occurrence of AKI after ICU admission. Covariates were selected using LASSO regression. Univariable and multivariable logistic regression models were utilized to assess the association between BMI and the odds of developing AKI in patients undergoing coronary artery revascularization surgery, with results presented as odds ratios (OR) and 95 % confidence intervals (CI). Subgroup analyses were performed based on age, surgery, anticoagulant use, and the Sequential Organ Failure Assessment (SOFA) score was computed to further explore the association between BMI and AKI.Results    This study included 3017 patients who underwent coronary artery revascularization surgery, of whom 2172 (72.8 %) developed AKI. Increasing BMI was significantly associated with elevated odds of AKI in patients undergoing coronary revascularization (OR = 1.10, 95 % CI: 1.08-1.12), indicating a 10 % increase in AKI risk for each unit increase in BMI, adjusted for demographic variables (age and gender) in Model 1. After further adjustment in Model 2 for significant baseline characteristics including comorbidities (type 2 diabetes, heart failure, malignant tumors, and chronic kidney disease) and ICU scoring systems (SOFA, APS III, SAPS II, OASIS, and CCI), the association remained significant with an 11 % increased risk of AKI per BMI unit increase (OR = 1.11, 95 % CI: 1.08-1.13).Conclusion    BMI may be a promising parameter for assessing the risk of AKI in paty revascularization surgery, providing valuable information for risk stratification and management of ICU patients undergoing such procedures.