Predictive Value of the Atherogenic Index of Plasma and Systemic Inflammation Response Index for Contrast-Induced Acute Kidney Injury in STEMI Patients Undergoing PCI

Objective This study aimed to investigate the association of the atherogenic index of plasma (AIP) and systemic inflammation response index (SIRI) with contrast-induced acute kidney injury (CI-AKI) in ST-segment elevation myocardial infarction (STEMI) patients undergoing emergency percutaneous coronary intervention (PCI), and to develop a predictive nomogram. Methods We retrospectively analyzed 1080 STEMI patients who underwent emergency PCI. Patients were randomly divided into a training cohort (n = 756) and a validation cohort (n = 324) in a 7:3 ratio. Based on the ESUR criteria, the training cohort was categorized into CI-AKI (n = 136) and non-CI-AKI (n = 620) groups. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors. A nomogram was constructed and validated using ROC curves, calibration plots, and decision curve analysis (DCA). The dose-response relationships were examined using restricted cubic splines (RCS). Results AIP and SIRI levels were significantly higher in the CI-AKI group (both P  < 0.001). Multivariate analysis identified AIP (OR = 8.74, 95% CI: 4.53–16.87), SIRI (OR = 1.28, 95% CI: 1.18–1.39), chronic kidney disease, and diuretic use as independent risk factors for CI-AKI. The nomogram incorporating these factors achieved AUCs of 0.853 and 0.873 in the training and validation sets, respectively, with good calibration and clinical utility. RCS analysis revealed a nonlinear dose-response relationship between AIP/SIRI and CI-AKI risk. The combination of AIP and SIRI demonstrated superior predictive performance (AUC = 0.817) than either index alone ( P  < 0.001). Conclusion AIP and SIRI are independent risk factors for CI-AKI in STEMI patients after PCI. Their combination improved discrimination. The constructed nomogram provides a practical tool for early risk assessment and identification of high-risk patients.