Prognostic nutritional index in the prediction of adverse cardiac and cerebrovascular events in ST-segment elevation myocardial infarction patients with type 2 diabetes mellitus in Urumqi, China: a retrospective cohort study

OBJECTIVE: Prognostic nutritional index (PNI) is an index for assessing nutritional and immune status. The aim of this study is to investigate the predictive value of PNI for long-term major adverse cardiac and cerebrovascular events (MACCE) in ST-segment elevation myocardial infarction (STEMI) patients with type 2 diabetes mellitus (T2DM). DESIGN, SETTING AND PARTICIPANTS: This retrospective cohort study analysed 1582 STEMI patients with T2DM who underwent percutaneous coronary intervention from January 2015 to June 2023 in Urumqi, China. Patients were followed up for MACCE. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint was new-onset MACCE including all-cause death, non-fatal MI and non-fatal stroke. RESULTS: This study ultimately included 1582 patients for analysis with a median follow-up period of 48 months (IQR: 24-84 months) and 282 patients (17.8%) developed MACCE. Of them, 138 (8.7%), 84 (5.3%) and 60 (3.8%) patients developed all-cause death, a non-fatal MI and a non-fatal stroke, respectively. Incidences of MACCE and all-cause death conversely correlated with PNI. Kaplan-Meier curves showed a significant difference in all components of MACCE between PNI quartiles (p<0.001). The multivariate Cox regression analysis revealed that PNI was an independent predictor of MACCE (adjusted HR 0.95, 95% CI 0.93 to 0.97, p<0.001) and all-cause death (adjusted HR 0.93, 95% CI 0.90 to 0.97, p<0.001). The optimal PNI cut-off for predicting MACCE and all-cause death was 45.10 and 45.09, respectively. Moreover, the addition of PNI to the traditional prognostic model for MACCE improved the C-statistic value (p<0.001). CONCLUSIONS: PNI, a simple and easily obtainable index, was independently associated with MACCE and all-cause death in this study. Lower PNI levels were significantly linked to an increased risk of long-term MACCE, especially in male, elderly patients and those with higher glycosylated haemoglobin and low- density lipoprotein cholesterol levels.