Abstract 4778: Postoperative ST2 Blood Concentrations Predict One Year Mortality in Coronary Artery Bypass Patients
Soluble ST2 (sST2) is released from myocytes in response to mechanical overload and predicts poor outcome in heart failure and myocardial infarction. We evaluated the capability of early sST2 release after coronary artery bypass surgery (CABG) to predict mortality during the first postoperative year. We prospectively evaluated sST2 baseline prior to CABG (BL), immediately after CABG (post), and 24h and 72h. The primary endpoint of the study was all-cause mortality at 1 year. Of the 210 patients enrolled, death occurred in 3 (1.5%) within 30 days and 20 (9.5%) by 1 year. sST2 levels did not change immediately post-CABG (BL: 0.32±0.42, post: 0.42±0.46) but became significantly elevated at 24h and 72h (3.39±3.08, 0.95±1.04 ng/ml; P<0.001). Compared to survivors, sST2 was significantly elevated in decedents at 24h (7.68±3.15 vs. 2.78±2.56, P<0.001) and 72h (1.56±1.62 vs. 0.88±0.44, P<0.03). On ROC analysis, sST2 at 24h strongly predicted death at 1 yr (AUC 0.868, 95% CI=0.77– 0.96). In multivariate analysis, sST2 level was a more powerful predictor of death (OR 17.0, P<0.0001) than traditional predictors (STS risk score, age, left ventricular ejection fraction) or other biomarkers (OR 1.59, P<0.0001) including troponin I, CPK-MB, and NT-pBNP. Although operative mortality was better than predicted by STS score, the 9.5% risk of death over 1yr highlights the need to better stratify mortality risk in order to guide appropriate follow-up after hospital discharge. As a strong predictor of 1yr mortality, independent of traditional laboratory or clinical variables, the sST2 level at 24 hrs may help advance this goal.