Prognostic Significance of Malnutrition Indices in ST-Elevation Myocardial Infarction: A Comparative Analysis of CONUT and PNI Scores After Primary PCI

<b>Background:</b> The purpose of this study was to compare the prognostic value of Controlling Nutritional Status (CONUT) and Prognostic Nutritional Index (PNI) scores for predicting in-hospital mortality among patients who presented with ST-segment elevation myocardial infarction (STEMI) and received primary percutaneous coronary intervention (P-PCI). <b>Methods:</b> This retrospective cohort study comprised 4599 STEMI patients who received P-PCI. The primary outcome was described as in-hospital mortality. Multivariable logistic regression analysis was performed to determine the association between in-hospital mortality and CONUT and PNI scores. Model performance and goodness-of-fit measures were used for comparison. <b>Results</b>: In-hospital mortality rate was 5.7% (<i>n</i> = 261). Patients who died during the index hospitalization were older and more likely to have diabetes, prior myocardial infarction (MI), revascularization history, longer total ischemic time, no-reflow and reduced left ventricular ejection fraction (LVEF). According to body mass index (BMI) categories, moderate-to-severe malnutrition was observed in approximately 17-21% and 8-10% of patients according to the CONUT and PNI scores, respectively. Both CONUT and PNI scores were significantly associated with in-hospital mortality. However, the model incorporating CONUT demonstrated superior goodness of fit and higher discriminative performance compared with the model incorporating PNI. <b>Conclusions:</b> Among patients with STEMI, moderate-severe malnutrition was present in nearly 10% and 20% when evaluated using PNI and CONUT, respectively. The CONUT score demonstrated superior predictive performance for in-hospital mortality compared with PNI.