While established biomarkers like BNP and NT-proBNP excel in diagnosing acute HF via natriuretic pathways, they offer limited insight into oxidative stress and extracellular matrix remodeling—processes central to HF progression where TETRA and PON1 hold unique potential, as evidenced by their dysregulation in related cardiovascular conditions [7,8]. Here, PON1 is linked to hydrops fetalis.