Prognostic role of soluble suppression of tumorigenicity-2 on cardiovascular mortality in outpatients with heart failure

OBJECTIVE: Soluble suppression of tumorigenicity-2 (sST2), a member of the interleukin 1 receptor family, is increased in mechanical stress conditions and is produced by cardiomyocytes and cardiac fibroblasts. Elevated sST2 level is associated with the prognosis of acute coronary syndrome, pulmonary arterial hypertension, and acute and chronic heart failure (HF). In this study, we aimed to investigate the relationship between sST2 levels and cardiovascular mortality in outpatients with HF. METHODS: This study used a prospective observational cohort design. A total of 130 consecutive outpatients with HF were prospectively evaluated. Clinical characteristics, laboratory results, cardiovascular risk factors, comorbidities, and medication use were recorded. The patients were followed up for a mean period of 12±4 months for the development of cardiovascular death. They were classified into two groups: those who survived and those who died. RESULTS: Mean age of patients was 67±11 years (69% males). After follow-up, 23 of 130 patients (18%) experienced cardiovascular death. sST2 levels were higher among those who died compared with among those who survived [51 (21–162) vs. 27 (9–198) ng/mL, p<0.001]. Optimal cut-off sST2 level to predict cardiovascular mortality was found to be >30 ng/mL with a sensitivity of 87% and a specificity of 67% (AUC =0.808, 95% CI=0.730 to 0.872). sST2 levels were negatively correlated with left ventricular ejection fraction and triglyceride, total cholesterol, LDL cholesterol, and hemoglobin levels and were positively correlated with left atrium size and the presence of right ventricular dilatation. In multiple Cox regression analysis, sST2 level of >30 ng/mL (HR=6.756, p=0.002, 95% CI=1.983–23.018), hemoglobin level (HR=0.705, p<0.001, 95% CI=0.587–0.847), age (HR=1.050, p=0.013, 95% CI=1.010–1.091), and HDL cholesterol level (HR=0.936, p=0.010, 95% CI=0.889–0.984) remained to be associated with an increased risk of mortality. CONCLUSION: sST2 measurement could help risk stratification in outpatients with HF. Moreover, this is the first study describing the impact of sST2 protein in Turkish patients with HF.