Contrast-induced nephropaty (CIN) remains a clinically important complication after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). Metabolic dysfunction, particularly insulin resistance and atherogenic dyslipidemia, may increase susceptibility to renal injury after contrast exposure. We aimed to compare the predictive value of the triglyceride–glucose (TyG) index, triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio, and triglyceride-to-low-density lipoprotein cholesterol (TG/LDL-C) ratio for CIN in ACS patients undergoing PCI.

This single-center retrospective observational study included 302 consecutive patients with ACS who underwent PCI between May 2025 and February 2026. CIN was defined as an absolute increase in serum creatinine of ≥0.5 mg/dL or a relative increase of ≥25% within 48–72 hours after contrast exposure. Demographic, clinical, laboratory, and echocardiographic data were retrieved from electronic medical records. The TyG index was calculated as [triglycerides (mg/dL) × glucose (mg/dL)/2]. Logistic regression analyses were performed to identify independent predictors of CIN. Receiver operating characteristic (ROC) analysis was used to assess discriminative performance.

CIN developed in 39 of 302 patients (12.9%). Those patients with CIN had lower estimated glomerular filtration rate and hemoglobin levels, but higher triglycerides, white blood cell count, systemic immune-inflammation index (SII), TyG index, TG/HDL-C ratio, and TG/LDL-C ratio (all p<0.05). In multivariable logistic regression analysis, TyG index (OR 5.48, 95% CI 2.49–12.07, p<0.001) and TG/LDL-C ratio (OR 2.01, 95% CI 1.21–3.33, p=0.007) were found as independent predictors of CIN. In ROC analysis, the TyG index showed the highest discriminative performance (AUC 0.782, 95% CI 0.716–0.848), followed closely by TG/LDL-C ratio (AUC 0.780, 95% CI 0.709–0.850), TG/HDL-C ratio (AUC 0.738, 95% CI 0.661–0.816), and inverse eGFR (AUC 0.735, 95% CI 0.655–0.815), all p<0.001. Optimal cut-off values were 9.01 for TyG index and 1.27 for TG/LDL-C ratio.

Among ACS patients undergoing PCI, the TyG index and TG/LDL-C ratio were independently associated with CA-AKI and showed the best discriminatory performance among the evaluated metabolic indices. These readily available and inexpensive parameters may improve preprocedural risk stratification and help identify patients who may benefit from intensified preventive strategies against CA-AKI.