Objectives:To investigate the prognostic value of soluble growth stimulation expressed gene 2 protein(sST2)combined with N-terminal pro-brain natriuretic peptide(NT-proBNP)in patients with ST-segment elevation myocardial infarction(STEMI)undergoing primary percutaneous coronary intervention(PCI). Methods:A total of 206 patients who were diagnosed with STEMI for the first time and underwent emergency PCI from August 2020 to February 2021 in the People's Hospital of Liaoning Province were enrolled.Patients were followed up for 3 years and divided into major adverse cardiac event(MACE,a composite endpoint event including cardiac death,stroke,heart failure,and ischemia-driven revascularization)group and MACE-free group.Multivariate cox analysis was performed to determine the independent risk factors for the prognosis of primary PCI in STEMI patients;the predictive value of sST2 and NT-proBNP for the occurrence of MACE in STEMI patients undergoing primary PCI was assessed by ROC analysis and the prediction of MACE by each factor by itself and the combined variables was analyzed with the Delong test. Results:There were 62 cases of MACE during the 3-year follow-up.Compared with the MACE-free group,patients in the MACE group had higher levels of sST2 and NT-proBNP,higher proportion of patients with left anterior descending branch lesions,anterior wall myocardial infarction,lower LVEF,and higher proportion of coronary artery slow flow(all P<0.05).Multivariate Cox analysis showed that sST2(HR=1.018,95%CI:1.012-1.024,P<0.001)and NT-proBNP(HR=1.001,95%CI:1.000-1.010,P<0.001)were independent predictors of MACE.According to the statistical analysis of ROC and Delong test,the AUC of combined sST2 and NT-proBNP in predicting MACE was 0.854,the sensitivity was 64.5%,the specificity was 93.1%,and the combined prediction of prognosis was better than that of individual prediction,with statistically significant difference(Z=2.119,P=0.034;Z=2.178,P=0.029). Conclusions:Serum sST2 and NT-proBNP are valuable predictors of MACE after emergency PCI in patients with STEMI,and the predictive efficacy increases with combined assessment of both sST2 and NT-proBNP.