The prevalence of diabetes and cardiovascular diseases in China has been increasing annually, and it has been demonstrated that diabetes can exacerbate the adverse effects of cardiovascular diseases through nutritional and inflammatory pathways. The prognostic nutritional index (PNI) is a marker of immunonutrition that reflects the inflammation, immune status and nutritional status of an individual. Due to its advantages of simplicity, rapidity, accessibility, and reliability, research on PNI has been increasing, yet its role in cardiovascular diseases has been less explored.

To investigate the relationship between PNI and major in-hospital adverse cardiovascular events (MACE) in patients with acute ST-elevation myocardial infarction (STEMI) complicated by type 2 diabetes mellitus (T2DM) following percutaneous coronary intervention (PCI) .

A retrospective analysis of 1 053 STEMI patients with T2DM who underwent PCI at the First Affiliated Hospital of Xinjiang Medical University from January 2015 to June 2023 was conducted. The patients were divided into the MACE (n=177) and non-MACE (n=876) groups according to the occurrence of MACE during hospitalization, and further categorized into the high PNI (n=686) and low PNI (n=367) groups according based on the cutoff value of PNI to predict the occurrence of in-hospital MACE after PCI in patients with STEMI and T2DM. Univariate and multivariate Logistic regression analyses identified factors influencing in-hospital MACE after PCI in patients with STEMI and T2DM. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of PNI for in-hospital MACE, and the area under the curve (AUC) was calculated. Pearson correlation analysis or Spearman rank correlation analysis was used to explore the correlation between PNI and cardiovascular disease risk factors.

The differences between the MACE and non-MACE groups in gender, age, history of hypertension, serum glucose, Killip classification, lactate dehydrogenase, heart rate, myoglobin, creatine kinase-MB isoenzyme (CK-MB), white blood cell count, brain natriuretic peptide (BNP), PNI, Global Registry of Acute Coronary Events (GRACE) score, hemoglobin, platelet count, lymphocyte count, albumin, total protein, creatinine, urea nitrogen and triacylglycerol were statistically significant (P<0.05). The results of multivariate Logistic regression analysis showed that elevated serum glucose (OR=1.055, 95%CI=1.002-1.112, P=0.044) and higher GRACE score (OR=1.034, 95%CI=0.876-0.939, P<0.001) were risk factors for in-hospital MACE, while increased PNI (OR=0.907, 95%CI=1.017-1.050, P<0.001) was a protective factor. The AUC of PNI for predicting in-hospital MACE was 0.734 (95%CI=0.694-0.773). A predictive model was constructed by Logistic regression analysis, and the model predicted an AUC of 0.791 (95%CI=0.753-0.858) for the occurrence of in-hospital MACE after PCI in patients with STEMI complicated by T2DM. The low PNI group showed higher incidence of MACE and proportion of intra-aortic balloon counterpulsation, longer hospitalization duration, higher levels of serum glucose, troponin T, CK-MB, myoglobin, BNP, C-reactive protein, creatinine, and urea nitrogen than those in the high PNI group; and lower optical coherence tomography ratio, total cholesterol, triacylglycerol, HDL-C, and hemoglobin levels than those in the high PNI group (P<0.05). The results of correlation analysis showed that PNI was positively correlated with hemoglobin, HDL-C, total cholesterol, and triacylglycerol (P<0.05) ; PNI was negatively correlated with serum glucose, creatinine, urea nitrogen, BNP, troponin T, CK-MB, myoglobin, and C-reactive protein (P<0.05) .

PNI is an independent predictive factor for in-hospital MACE in STEMI patients with T2DM after PCI, which can serve as an auxiliary indicator for monitoring patients' immunonutritional status and predicting their short-term prognosis.