Objective: Contrast-induced nephropathy (CIN) is associated with significantly increased morbidity and mortality after percutaneous coronary intervention (PCI). Patients with acute coronary syndrome (ACS) are at higher risk of CIN. The platelet-to-lymphocyte ratio (PLR) is closely linked to inflammatory conditions. We hypothesized that PLR levels on admission can predict the development of CIN after PCI for ACS. Subjects and Methods: A total of 426 patients (mean age 63.17 ± 13.01 years, 61.2% males) with ACS undergoing PCI were enrolled in this study. Admission PLR levels were measured before PCI. Serum creatinine values were measured before and within 72 h after the administration of contrast agents. Patients were divided into 2 groups: the CIN group and the no-CIN group. CIN was defined as an increase in serum creatinine level of ≥0.5 mg/dl or 25% above baseline within 72 h after contrast administration. Results: CIN developed in 53 patients (15.9%). Baseline PLR was significantly higher in patients who developed CIN compared to those who did not (160.8 ± 29.7 and 135.1 ± 26.1, respectively; p < 0.001). Multivariate analyses found that PLR [odds ratio (OR) 3.453, 95% confidence interval (CI) 1.453-8.543; p = 0.004] and admission creatinine (OR 6.511, 95% CI 1.759-11.095; p = 0.002) were independent predictors of CIN. Conclusions: The admission PLR level is an independent predictor of the development of CIN after PCI in ACS.
