Prognostic Associations of the Naples Score for Clinical Outcomes in Patients With Acute Myocardial Infarction: A Systematic Review and a Prognostic Meta‐Analysis

Background The Naples Prognostic Score (NPS) is a composite inflammatory‐nutritional index that integrates serum albumin, total cholesterol, neutrophil‐to‐lymphocyte ratio, and lymphocyte‐to‐monocyte ratio to predict outcomes in acute myocardial infarction (MI); however, its independent prognostic value remains incompletely defined. Objective To assess the correlation between the NPS and outcomes in patients with acute MI. Methods We searched PubMed, Scopus, Cochrane, Embase, and Wiley Online Library for studies evaluating the NPS in patients with acute MI. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random‐effects models, and heterogeneity was assessed using the I 2 statistic. Results Nine observational cohort studies comprising 15,998 patients with MI were analyzed. Higher NPS was associated with increased odds of all‐cause mortality (OR 3.31; 95% CI: 1.62–6.77, p = 0.0130), no‐reflow phenomenon (OR 1.40; 95% CI 1.11–1.76; p = 0.0248), and new‐onset atrial fibrillation (OR 2.17; 95% CI: 1.62–2.91; p = 0.008). The association with in‐hospital mortality did not reach statistical significance in the primary pooled analysis (OR 1.90; 95% CI: 0.66–5.44, p = 0.147), with substantial heterogeneity driven by a single influential study. Conclusion Higher NPS was correlated with higher risk of all‐cause mortality, no‐reflow phenomenon, and new‐onset atrial fibrillation in patients with acute MI. All estimates are based on observational data that have not been adjusted for any factors; there were three to four cohorts per outcome, and eight of nine studies were from one country. The findings are exploratory and do not warrant the use of NPS as a clinical risk stratification tool; future, adjusted, multinational validation is needed.