Associations of Soluble Serum Stimulation‐2 With Functional Outcomes and Death at 1 Year in Acute Ischemic Stroke: A Prospective Cohort Study

Background Elevated sST2 (soluble serum stimulation‐2) has been associated with poor 90‐day outcomes of patients with acute ischemic stroke (AIS). We aimed to investigate the associations between baseline serum sST2 level and 1‐year outcomes in patients with AIS. Methods and Results This was a prospective, observational, cohort study, enrolling patients with AIS with sST2 levels measured using serum samples obtained within 24 hours of onset. The primary outcome was 1‐year functional dependence (modified Rankin Scale score 3–5) or all‐cause death. Secondary outcomes included 1‐year functional dependence, all‐cause death, and modified Rankin Scale score distribution, analyzed separately. Logistic regression, shift analyses of the modified Rankin Scale score, and restricted cubic splines were used to examine the association of sST2 level with 1‐year outcomes. Among 312 patients (median age 61 years, 28.5% women), 37 (11.9%) had a primary outcome (27 with functional dependence, 10 all‐cause deaths). Serum sST2 level >24.6 ng/mL was independently associated with the primary outcome and secondary outcomes. Higher continuous sST2 level was significantly associated with the primary outcome and functional dependence, and tended to be associated with 1‐year all‐cause death and higher modified Rankin Scale score. Multivariable‐adjusted restricted cubic splines showed a linear relationship between higher sST2 level and 1‐year risk of primary outcome, functional dependence, or all‐cause death. In subgroup analyses, higher serum sST2 level was more significantly associated with the primary outcome in those with than without prior AIS beyond 1 year before the index AIS and coronary artery disease. Conclusions Higher serum sST2 level within 24 hours of onset could be a promising predictor of 1‐year worse functional outcomes and death after AIS.