Prognostic value of the prognostic nutritional index for patients with acute myocardial infarction undergoing percutaneous coronary intervention with variable glucose metabolism statuses: a retrospective cohort study

BACKGROUND: The prognostic nutritional index (PNI) and different glucose metabolisms have been separately reported to be correlated with long-term prognosis in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). However, PNI application in patients with an impaired glucose metabolism has not been well validated, especially in pre-diabetic patients. This study evaluated whether PNI influences a long-term risk of mortality along different glucose metabolism statuses. METHODS: A total of 17,697 patients with AMI and a history of PCI were enrolled in this retrospective observational cohort study from January 2007 to December 2020. Three subgroups with different glucose metabolism statuses, including normal glucose regulation (NGR), pre-diabetes mellitus (pre-DM), and diabetes mellitus (DM), were divided into three groups according to the tertiles of PNI, respectively. RESULTS: All-cause mortality occurred in 2613 (14.8%) patients within a median of 4.1 years of follow-up. Upon analyzing the Kaplan–Meier plots for the NGR, pre-DM, and DM groups, the incidence of all-cause or cardiovascular mortality in the low PNI (PNI-L, ≤ 42.7) subgroup was significantly higher than that in the median PNI (PNI-M, > 42.7 and ≤ 48.2) and high PNI (PNI-H, > 48.2) subgroups (all, P < 0.001). After adjusting for confounding factors, the hazard ratio (HR) for all-cause mortality in the PNI-L group significantly increased compared to that in the PNI-H subgroups of the NGR group (HR, 1.35; 95% CI 1.14–1.66; P < 0.001), pre-DM group (HR, 1.29; 95% CI 1.02–1.62; P < 0.001), and DM group (HR, 1.36; 95% CI 1.13–1.63; P < 0.001). Given that there was evidence of interactions between PNI and different glucose statuses (P for interaction < 0.001), patients were divided into nine subgroups, and we found that DM patients with PNI-L statuses had the highest risk of all-cause mortality compared to NGR patients with PNI-H statuses (HR, 1.69; 95% CI 1.42–2.01; P < 0.001). CONCLUSION: Lower PNI is a significant and independent risk factor for all-cause mortality in AMI patients undergoing PCI with different glucose metabolism statuses, and this risk further increases with DM compared to NGR or pre-DM statuses. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-023-01160-4.