Prognostic Value of Systemic Immune-Inflammation Index and NT-proBNP in Patients with Acute ST-Elevation Myocardial Infarction

OBJECTIVE: Our aim was to assess systemic immune-inflammation index (SII) and NT-proBNP value either in singly or in combination to predict acute ST-elevation myocardial infarction (STEMI) patient prognosis. METHODS: Analyzed retrospectively the clinical features and laboratory data of STEMI confirmed patients in our hospital from January to December 2020. The levels of SII and NT-proBNP were detected. The Kaplan-Meier approach and Spearman’s rank correlation coefficient were used to construct the overall major adverse cardiac event (MACE) curve. Multivariate Cox regression analysis was applied to detect MACE predictors. In addition, the Delong test and receiver operating characteristic (ROC) curve analyzed each factor performance on its own and composite multivariate index to predict MACEs. RESULTS: The MACE group showed statistically significant differences in SII, NT- proBNP in comparison to the non-MACE group (P=0.003, P <0.001). Based on Kaplan-Meier analysis, SII and NT-proBNP showed positive correlation with MACE (log-rank P < 0.001). SII and NT-proBNP were independent predicting factors for long-term MACEs in multivariate Cox regression analysis (P <0.001, HR: 2.952, 95% CI 1.565–5.566; P <0.001, HR: 2.112, 95% CI 1.662–2.683). SII and NT-proBNP exhibited a positive correlation (R = 0.187, P < 0.001) in correlation analysis. According to the ROC statistical analysis, the combination exhibited 78.0% sensitivity and 88.0% specificity in the prediction of MACE. According to the results of the AUC and Delong test, the combined SII and NT-proBNP performed better as a prognostic index than each of the individual factor indexes separately (Z = 2.622, P = 0.009; Z = 3.173, P < 0.001). CONCLUSION: SII and NT-proBNP were independent indicators of clinical prognosis in acute STEMI patients, and they correlated positively. These factors could be combined to improve clinical prognosis.