NPPB and hydrops fetalis: In this context, biomarkers capable of identifying patients at increased long-term risk may enhance follow-up strategies and inform therapeutic decisions.3 Among the most promising, N-terminal pro–B-type natriuretic peptide (NT-proBNP) is a well-established marker of myocardial wall stress and is widely used for both the diagnosis and prognostication of heart failure (HF).4 In AS, elevated NT-proBNP levels have been associated with symptom onset, disease severity, and adverse outcomes.