Prognostic Value of the CALLY Index in Predicting Contrast-Associated Acute Kidney Injury in Patients With Acute Coronary Syndrome

Contrast-associated acute kidney injury (CA-AKI) is a serious complication associated with increased morbidity and mortality in patients with acute coronary syndrome (ACS) undergoing coronary angiography. The C-reactive protein-albumin-lymphocyte (CALLY) index is a novel biomarker reflecting inflammatory and nutritional status. This retrospective study evaluated the prognostic value of the CALLY index calculated at hospital admission for predicting CA-AKI in 1516 patients with ACS. CA-AKI developed in 267 patients (17.6%). Patients who developed CA-AKI had significantly lower CALLY index values (0.35 ± 0.16 vs 0.84 ± 0.30; P < .001). In separate multivariable logistic regression analyses adjusted for baseline clinical and procedural confounders, the CALLY index emerged as an independent predictor of CA-AKI (Odds ratio [OR] 0.592 per 0.1-unit increase; 95% CI 0.525-0.668; P < .001). Receiver operating characteristic curve analysis demonstrated good discriminatory capacity for the CALLY index (Area Under the Curve [AUC] = 0.822), significantly outperforming conventional clinical scores and other inflammatory indices (DeLong test P < .001). Furthermore, adding the CALLY index to the Mehran risk score significantly improved reclassification metrics (Net Reclassification Improvement [NRI] = 14.2%, Integrated Discrimination Improvement [IDI] = 0.048; P < .001). The CALLY index serves as a simple, practical, and effective score for early CA-AKI risk stratification in ACS.