Association of prognostic nutritional index with long-term mortality in patients receiving percutaneous coronary intervention for acute coronary syndrome: a meta-analysis

The predictive value of the prognostic nutritional index (PNI) for the long-term prognosis of patients with acute coronary syndrome (ACS) remains uncertain. Medline, Embase, Cochrane Library, and Google Scholar were searched from inception until January 2023 to study the relationship between all-cause mortality risk and PNI in patients receiving percutaneous coronary intervention for ACS (i.e., primary outcome). Thirteen observational studies were included in this meta-analysis. Analysis of seven studies using PNI as a categorical variable showed a pooled hazard ratio (HR) of all-cause mortality of 2.97 (95% CI 1.65 to 5.34, p = 0.0003, I2 = 89%, n = 11,245) for patients with a low PNI. The meta-analysis also showed a higher risk of major adverse cardiovascular events (MACEs) in patients with a low PNI (HR 2.04; 95% CI 1.59 to 2.61; p < 0.00001; I2 = 21%; n = 8534). Moreover, advanced age, diabetes mellitus, and high Global Registry of Acute Coronary Events risk scores were associated with a high risk of all-cause mortality, whereas a high body mass index was associated with a low risk of all-cause mortality. The results showed an association between a low PNI and an increased risk of long-term mortality in patients undergoing coronary interventions for ACS. Further randomized controlled trials are necessary to confirm these findings.