NPPB and hydrops fetalis: Elevated plasma TMAO levels have been shown to independently predict long-term mortality in patients with stable HF, even after adjusting for B-type Natriuretic Peptide (BNP) and renal function [45], whereas Suzuki et al. [46] reported that in acute HF, higher circulating TMAO concentrations were significantly associated with in-hospital and one-year mortality, enhancing prognostic discrimination beyond traditional biomarkers.