Unveiling the impact of prognostic nutritional index on one-year outcomes in chronic anemia patients with acute myocardial infarction: insights from a multicenter retrospective study

Background Chronic anemia frequently complicates acute myocardial infarction (AMI) and is associated with adverse outcomes. The Prognostic Nutritional Index (PNI), calculated as 10×serum albumin (g/dL)+0.005×lymphocyte count (per μL), is a validated marker of nutritional and immune status. However, its association with long-term prognosis in AMI patients with chronic anemia remains unclear. This study aimed to investigate the relationship between PNI and one-year outcomes in this high-risk population. Methods This retrospective multicenter study included 23,162 patients (68.3 ± 11.3 years; 81.0% male) with chronic anemia and AMI from 82 hospitals in China. Patients were stratified into two groups based on PNI score: well-nourished (PNI > 38, n = 10,419) and moderate-to-severe nutritional deficit (PNI ≤ 38, n = 12,743). The primary endpoint was one-year net adverse clinical events (NACE), a composite of all-cause death, recurrent MI, cerebral infarction, and BARC type 3 ,or 5 bleeding. Secondary endpoints included all-cause death, cardiac death, BARC type 3, or 5 bleeding, and cerebral infarction. Data were analyzed using Kaplan-Meier survival curves and multivariate Cox regression models. Results Over a follow-up of 1 year, the well-nourished group experienced significantly higher rates of NACE (adjusted hazard ratio [aHR]: 1.27, 95% CI: 1.19–1.35, P < 0.001), all-cause death (aHR: 1.47, 95% CI: 1.35–1.59, P < 0.001), cardiac death (aHR: 1.38, 95% CI: 1.25–1.51, P < 0.001), bleeding events (aHR: 1.56, 95% CI: 1.37–1.78, P < 0.001), and cerebral infarction (aHR: 1.24, 95% CI: 1.05–1.47, P = 0.013) compared to the moderate-to-severe deficit group (Figure 1). Kaplan-Meier analysis revealed consistent findings with the earlier described outcomes (Figure 2). No significant differences were observed in recurrent MI or cerebral hemorrhage. Multivariate analysis confirmed PNI ≤ 38 as an independent predictor of adverse outcomes. Conclusions In patients with chronic anemia and AMI, a PNI score ≤38 is associated with increased risks of one-year NACE, all-cause death, cardiac death, bleeding events, and cerebral infarction. These findings underscore the importance of nutritional assessment using PNI in this high-risk population and suggest potential benefits of targeted nutritional interventions. Future prospective studies are needed to validate these results and explore the efficacy of nutritional support.Figure 1.Cox Regression Analysis Figure 2.