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

Abstract

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.

Keywords: Diabetic nephropathy & vascular disease; Ischaemic heart disease; Myocardial infarction.

Figure 1. Flow diagram of the study design and patient recruitment. MACCE, major adverse cardiac and cerebrovascular events; PCI, percutaneous coronary intervention; PNI, prognostic nutritional index; STEMI, ST-segment elevation myocardial infarction; T2DM, type 2 diabetes mellitus.

Figure 2. Kaplan-Meier curve showed the incidence of MACCE, all-cause death, non-fatal MI and non-fatal stroke at different PNI levels. (A) Kaplan-Meier curve of MACCE; (B) Kaplan-Meier curve of all-cause death; (C) Kaplan-Meier curve of non-fatal MI; (D) Kaplan-Meier curve for non-fatal stroke. MI, myocardial infarction; MACCE, major adverse cardiac and cerebrovascular events.

Figure 3. Restricted cubic spline curves of PNI and MACCE events and all-cause deaths after adjusting the variables of model 3. (A) Restricted cubic spline curve of MACCE; (B) restricted cubic spline curves for all-cause death. MACCE, major adverse cardiac and cerebrovascular events; PNI, prognostic nutritional index.

Figure 4. (A) Time-ROC curve of PNI prediction of MACCE occurrence. (B) Time-AUC curve of PNI predicting MACCE occurrence. (C) Time-AUC curve with and without PNI predicted the time correlation of MACCE occurrence. The dotted line represents the respective 95% CI. AUC, area under the curve; MACCE, major adverse cardiac and cerebrovascular events; PNI, prognostic nutritional index; ROC, receiver operating characteristic.

Figure 5. Cox regression analysis evaluated the prognostic value of PNI in different stratifications. PNI was incorporated into model 3 as a continuous variable. BMI, body mass index; HbA1c, glycosylated haemoglobin; LDL-C, low-density lipoprotein cholesterol; PNI, prognostic nutritional index; SGLT-2, sodium-glucose transport protein 2.