Geriatric Nutritional Risk Index and in-hospital adverse events in patients with ST-segment elevation myocardial infarction

Purpose: Malnutrition and inflammation are common in ST-segment elevation myocardial infarction and may influence early vulnerability. We evaluated whether the admission Geriatric Nutritional Risk Index is associated with in-hospital adverse events, and compared it with the Prognostic Nutritional Index and the Controlling Nutritional Status score.Materials and Methods: This retrospective observational study included 748 consecutive adults with the infarction treated between January 2024 and December 2025. The nutritional index was calculated from admission albumin, weight, height, and sex. The primary endpoint was a composite of in-hospital ventricular tachycardia or fibrillation, intubation, death, contrast-associated acute kidney injury, cardiogenic shock, intra-aortic balloon pump, or cardiopulmonary resuscitation; a prespecified nonrenal composite was a sensitivity endpoint. The index was modeled continuously per 10-point lower value with logistic regression and bootstrap internal validation.Results: The primary endpoint occurred in 141 of 748 patients (18.9%). Median GNRI was 98.3 (interquartile range, 95.3–102.0). Each 10-point lower GNRI was associated with the primary endpoint before adjustment (odds ratio 1.61, 95% confidence interval 1.13–2.28) and after demographic and comorbidity adjustment (1.57, 1.10–2.23). The association was attenuated after additional adjustment for acute severity (0.99, 0.66–1.49), with a similar pattern for the nonrenal composite. The areas under the receiver-operating characteristic curve were 0.579 for GNRI, 0.564 for CONUT, and 0.457 for PNI.Conclusion: A lower admission index was associated with a higher risk of in-hospital mortality; however, this association was attenuated after accounting for acute illness severity. As a simple and readily available nutritional marker at admission, the index should be used as an indicator of overall frailty rather than as a standalone decision-making tool.