sST2 levels are associated with all-cause mortality in anticoagulated patients with atrial fibrillation

BackgroundAtrial fibrillation (AF) is associated with high morbidity and mortality, even despite the use of oral anticoagulation (OAC). Soluble suppression of tumorigenicity-2 (sST2) is a member of the interleukin-1 receptor family [interleukin-1 receptor-like 1 (IL1RL1)], which has been associated with an increased risk of mortality and morbidity in heart failure or acute coronary syndrome. We assessed the predictive value of sST2 levels in an unselected real-world' cohort of anticoagulated AF patients. MethodsWe included 562 patients (49% male; median age 77 [IQR: 71-82]) with permanent AF who were stable (for at least 6months) on OAC (INRs 20-30). sST2 levels were quantified by ELISA. Patients were followed-up for up to 4years, and cardiovascular events and all-cause mortality were recorded. ResultsMedian (IQR) of sST2 levels was 5123 (3909-6740)g/L. Median follow-up was 1587days [IQR 1482-1617], and during this period, 91 patients died (162%, 372%/year). The c-statistic for predicting mortality with sST2 was 058+003; P=0017). On multivariate analysis, age [hazard ratio (HR) 109 (105-113); P<0001], diabetes mellitus [176 (108-288); P=0023], previous stroke [216 (129-360); P=0003] and sST2 levels [1008 (1002-114); P=0008] were independently associated with mortality. Concentrations of sST2 were also significantly associated with the risk of mortality, even after adjusting for the CHA(2)DS(2)-VASc score [HR: 1007 (1001-1013); P=0014]. ConclusionsIn an anticoagulated AF patient's cohort, sST2 levels are an independent predictive factor of all-cause mortality. sST2 levels could be a biomarker used to improve clinical risk assessment in anticoagulated AF patients.