NPPB and hydrops fetalis: Data from the Pro-Brain Natriuretic Peptide Investigation of Dyspnea in the Emergency Department (PRIDE) study also highlighted the diagnosis and prognosis value of sST2 in HFrEF, its serum levels being significantly higher in patients with acute HF compared to patients without HF (0.50 vs. 0.15 ng/mL, p < 0.001), and in deceased patients compared to survivors (1.08 vs. 0.18 ng/mL) [56].