Soluble ST2 as an Independent Predictor of Post-discharge New-Onset Atrial Fibrillation in Patients with STEMI

Background New-onset atrial fibrillation (NOAF) represents a significant complication following ST-elevation myocardial infarction (STEMI). Soluble suppression of tumorigenicity 2 (sST2) is a biomarker reflecting myocardial stress and fibrosis. However, its predictive value for post-discharge NOAF in STEMI patients remains inadequately characterized. This study was to investigate whether elevated sST2 levels during hospitalization independently predict post-discharge NOAF in STEMI patients. Methods: This multicenter, prospective cohort study enrolled 648 consecutive STEMI patients. Serum sST2 concentrations were measured within 24 hours of admission using enzyme-linked immunosorbent assay. Multivariable logistic regression, receiver operating characteristic (ROC) curve analysis, and risk reclassification metrics were employed to assess sST2's predictive performance. Results: NOAF occurred in 56 patients (8.64%) during follow-up. Patients developing NOAF exhibited significantly higher sST2 levels compared to those without NOAF (62.84±54.62 vs. 30.37±34.71 ng/mL, P<0.001). After adjusting for confounders, sST2 remained an independent predictor of NOAF (OR=1.02, 95% CI: 1.01-1.02, P<0.001). The area under the ROC curve for sST2 was 0.785 (95% CI: 0.723-0.848). Incorporating sST2 into the clinical model significantly improved discrimination (AUC from 0.718 to 0.810, P<0.001) and risk reclassification (NRI=0.084, P=0.033; IDI=0.047, P=0.003). Restricted cubic spline analysis revealed a non-linear dose-response relationship between sST2 and NOAF risk. Conclusions: Elevated sST2 levels during hospitalization independently predict post-discharge NOAF in STEMI patients, offering incremental prognostic value beyond traditional risk factors.