Soluble ST2 Monitoring Provides Additional Risk Stratification for Outpatients With Decompensated Heart Failure

Introduction and objectives. The novel biomarker ST2 provides diagnostic information in a variety of clinical settings. The objective was to determine whether measurement of the soluble ST2 (sST2) concentration improves risk stratification in outpatients with decompensated heart failure (HF). Methods. The concentrations of sST2 and N-terminal probrain natriuretic peptide (NT-proBNP) and a heart failure severity score (HFSS), based on Framingham criteria, were determined at baseline and 2 weeks later in 48 outpatients with decompensated hf. The ratio of the value of each variable at week 2 relative to baseline was determined. Patients were followed for 1 year and cardiac events (i.e. death, HF admission and heart transplantation) were recorded. Results. By 1 year, 56% of patients had experienced a cardiac event. The sST2 ratio was significantly lower in patients who did not have a cardiac event (0.6 +/- 0.39 vs. 1.39 +/- 0.92; P<.001). After multivariable adjustment, the sST2 ratio remained an independent predictor of risk (odds ratio=1.054; 95% confidence interval, 1.01-1.09; P=.017). The optimum cut-point for the sST2 ratio determined by receiver operating curve [ROC] analysis was 0.75; this accounted for 25% of the change in sST2 by week 2. Among patients with an sST2 ratio >0.75 and a baseline NT-proBNP level >1000 ng/L, 72% had a cardiac event (P=.018), while no events occurred in patients with marker values below these reference levels. Conclusions. Determination of the sST2 concentration in serial samples provided additional risk stratification in outpatients with decompensated HF. Repeated measurement of sST2 may aid clinical decision-making.