ST2, an interleukin-1 (IL-1) receptor family member, is an emerging biomarker promising to assess prognosis in various pathophysiological conditions including heart failure (HF). The aim of this work was to investigate the prognosis interest of this marker in ambulatory patients with stable HF.

Patients were included in this study in 2010. All patients gave informed consent. Clinical characteristics were registered and biomarkers were assessed. Clinical outcomes were registered regularly by a clinical follow-up or by phone by a dedicated physician. We use the prognostic score of Lupon et al. including clinical data, NT pro-BNP, hs-c TnT and SST2 assay. Survival curves were built and data presented as means±SD when normally distributed.

180 patients (mean age 72.5y±12.5y) were included. Left ventricular ejection fraction was 37.1%±14.2%. ST2 concentrations are strongly predictive of all cause mortality [HR 3.15 (95% CI: 1.46-6.8)] and cardiovascular mortality [HR 4.28 (95% CI: 1.5-12.26)] regardless of NT pro-BNP concentrations. Estimation of the risk of all-cause and cardiovascular mortality was significantly improved by adding SST2, NT pro-BNP and hs-c TnT levels to clinical covariates. Risk of mortality was estimated using Cox proportionnal hazard models. Discrimination, assessed by c-index, rose from 0.678 for the clinical model to 0.715 after addition of biomarkers for prediction of all-cause mortality. For cardiovascular mortality, c-index was improved from 0.703 to 0.753. Added value of biomarkers was also evaluated by reclassification analysis. Associated net reclassification improvement (NRI) [95% CI] for 48 months death were 0.395 [0.068-0.653], p=0.033 and 0.395 [0.068-0.653], p=0.020 for all cause and cardiovascular death, respectively.

SST2 appears as a promising prognostic biomarker. It could provide additional information to natriuretic peptides