The Osaka Prognostic Score as a Novel Predictor of Contrast-Induced Nephropathy and In-Hospital Mortality in STEMI Patients Undergoing Primary Percutaneous Coronary Intervention.

Background: The Osaka Prognostic Score (OPS), derived from C-reactive protein, serum albumin, and total lymphocyte count, reflects systemic inflammation and nutritional status. This study evaluated the prognostic value of the OPS for predicting contrast-induced nephropathy (CIN) and in-hospital all-cause mortality in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). Methods: In this retrospective study, 2,769 consecutive STEMI patients treated with pPCI were analyzed. OPS was calculated on admission (range 0-3). Multivariable regression, receiver operating characteristic, and spline analyses were used to evaluate predictors and optimal cutoff values. Results: CIN occurred in 188 patients (6.8%), and 58 patients (2.1%) died during hospitalization. The mean OPS was significantly higher in patients who developed CIN compared with those who did not (1.86 ± 0.82 vs. 0.73 ± 0.70, p < 0.001). OPS independently predicted CIN (odds ratio: 6.817, 95% confidence interval: 5.157-9.012). For in-hospital mortality, OPS remained an independent predictor across all parsimonious multivariable Cox models, with adjusted hazard ratios ranging from 1.045 to 1.211 (all p < 0.05). An OPS cutoff value of ≥ 1.5 optimally predicted CIN (area under the curve [AUC]: 0.83) and in-hospital mortality (AUC: 0.73). Patients with an OPS of 3 had markedly higher rates of CIN (71.4%) and mortality (15.9%) than those with an OPS of 0 (0.7% and 0.5%, respectively; both p < 0.001). Kaplan-Meier analysis demonstrated a stepwise reduction in in-hospital survival with increasing OPS (log-rank p < 0.001). Conclusions: The OPS is a simple and effective tool for the early prediction of CIN and in-hospital mortality in STEMI patients undergoing pPCI, and may facilitate early risk stratification and targeted management.