Abstract： Background:Serum soluble ST2 (sST2) levels are elevated early after acute myocardial infarction and are related to adverse left ventricular (LV) remodeling and cardiovascular outcomes in ST-segment elevation myocardial infarction (STEMI).Beta-blockers (BB) have been shown to improve LV remodeling and survival.However,the relationship between sST2,final therapeutic BB dose,and cardiovascular outcomes in STEMI patients remains unknown.Methods:A total of 186 STEMI patients were enrolled at the Wuhan Asia Heart Hospital between January 2015 and June 2015.All patients received standard treatment and were followed up for 1 year.Serum sST2 was measured at baseline.Patients were divided into four groups according to their baseline sST2 values (high ＞56 ng/ml vs.low ≤56 ng/ml) and final therapeutic BB dose (high ≥47.5 mg/d vs.low ＜47.5 mg/d).Cox regression analyses were performed to determine whether sST2 and BB were independent risk factors for cardiovascular events in STEMI.Results:Baseline sST2 levels were positively correlated with heart rate (r =0.327,P =0.002),Killip class (r =0.408,P =0.000),lg N-terminal prohormone B-type natriuretic peptide (r =0.467,P =0.000),lg troponin I (r =0.331,P =0.000),and lg C-reactive protein (r =0.307,P =0.000) and negatively correlated to systolic blood pressure (r =-0.243,P =0.009) and LV ejection fraction (r =-0.402,P =0.000).Patients with higher baseline sST2 concentrations who were not titrated to high-dose BB therapy (P ＜ 0.0001) had worse outcomes.Baseline high sST2 (hazard ratio [HR]:2.653;95％ confidence interval [CI]:1.201-8.929;P =0.041) and final low BB dosage (HR:1.904;95％ CI,1.084-3.053;P =0.035) were independent predictors of cardiovascular events in STEMI.Conclusions:High baseline sST2 levels and final low BB dosage predicted cardiovascular events in STEMI.Hence,sST2 may be a useful biomarker in cardiac pathophysiology.