[Diagnostic value of combining serum soluble ST2 and interleukin-33 for heart failure patients with preserved left ventricular ejection fraction].

Objective: Diagnostic efficacy of serum markers is low for heart failure patients with preserved left ventricular ejection fraction (HF-pEF) as compared to heart failure patients with reduced left ventricular ejection fraction.We sought to explore the diagnostic value of serum levels of soluble ST2 (sST2) combined with interleukin-33 (IL-33) for the diagnosis of HF-pEF in this study. Methods: A total of 376 patients with HF-pEF (HF group), 376 matched-control patients without heart failure who shared similar clinical characteristics (non-HF group) were included in the study.Another 500 healthy individuals were recruited for assessing the normal ranges of IL-33 and sST2.Serum levels of NT-proBNP were measured by chemi-luminescence assay, while IL-33 and sST2 were measured by enzyme linked immunosorbent assay. Results: Serum levels of IL-33 and sST2 were not normally distributed in healthy population.Serum concentrations of IL-33 and sST2 were significantly higher in HF-pEF patients than in patients in non-HF group (median, IL-33: 0.437 μg/L vs. 0.127 μg/L, P <0.01; sST: 0.118 μg/L vs. 0.067 μg/L, P <0.01). The area under receiver operating characteristic curve (AUC) of sST2 for detecting HF-pEF was 0.763 (95% CI 0.729-0.795, P <0.01), with 71.01% sensitivity and 66.75% specificity, the AUC was 0.884 (95% CI 0.859-0.908, P <0.01), with 80.05% sensitivity and 81.91% specificity in patients with serum IL-33 higher than 0.117 μg/L (median level of serum IL-33 in healthy individuals, n =306). The AUC of NT-proBNP for detecting HF-pEF was 0.83, with 74.73% sensitivity and 84.57% specificity.The AUC of sST2 for detecting HF-pEF was significantly higher than NT-proBNP in population with high serum IL-33 (AUC: 0.88 vs. 0.83, P <0.01). Conclusion: Serum sST2 could serve as a satisfactory biomarker for HF-pEF diagnosis, especially for patients with high serum IL-33 concentrations.