Even though left ventricular ejection fraction contributes to the risk stratification of HF patients, the measuring of cardiac biomarkers (e.g., troponin (cTn) and brain natriuretic peptide (BNP) in biological fluids (e.g., blood, urine and saliva) are also useful in this population for diagnosis and management purposes [33,34] as well as to prognosticate for mortality and need for hospital readmission [34,35]. This evidence concerns the gene NPPB and hydrops fetalis.