Predictive value of monocyte-to-high-density lipoprotein cholesterol ratio for acute kidney injury following coronary artery bypass grafting

To evaluate the predictive value of preoperative monocyte-to-high-density lipoprotein cholesterol ratio (MHR) for acute kidney injury (AKI) after coronary artery bypass grafting (CABG). This retrospective single-center study enrolled 280 patients undergoing CABG at Shanghai East Hospital between January and December 2024. Eligible patients were aged ≥ 18 years, lacked prior chronic kidney disease, and had complete perioperative data. Preoperative MHR was calculated, and postoperative AKI was defined according to KDIGO criteria. Multivariate logistic regression identified independent predictors of AKI, with MHR standardized via Z-score transformation. Predictive performance was assessed using receiver operating characteristic (ROC) curves and 10-fold cross-validation; model calibration was evaluated using binned calibration plots and the Hosmer-Lemeshow test. The optimal MHR cutoff was determined by the Youden index, and patients were stratified accordingly. Postoperative serum creatinine trajectories were compared using linear mixed-effects models with Holm-adjusted pairwise tests. AKI occurred in 104 patients (37.1%). Multivariate regression revealed that preoperative MHR (per 1-SD increase: OR = 2.56, 95% CI: 1.77–3.80, p 0.658), the high-MHR group exhibited a significantly higher AKI incidence (64.29% vs. 22.53%, p < 0.001) and persistently elevated creatinine levels across all postoperative time points (CrH0–CrH72, all adjusted p ≤ 0.030). Subgroup analyses confirmed consistent associations between MHR and AKI across strata of age, cardiac function, hypertension, and diabetes, with no significant interaction effects. Preoperative MHR is a strong independent predictor of post-CABG AKI, with improved performance when combined with triglycerides and blood glucose.