TNNT2 and hydrops fetalis: To determine the prognostic value of collected parameters of HF, clinical characteristics of the patients, ECG results, bioelectrical impedance body mass analysis results, echocardiography results, key CPET parameters, 6MWT results, and laboratory data, including NTproBNP, hs-cTnT, hemoglobin, sodium, potassium, creatinine, uric acid, and biomarkers including neprilysin, galectin-3, and hs-CRP, ST-2 were subjected to analyses.