As secondary objectives, the HF-EI trial will evaluate AT oxygen uptake, 6-min walk distance (6MWD), left ventricle ejection fraction (LVEF), N-terminal prohormone of brain natriuretic peptide (NT pro-BNP), the Patient Health Questionnaire-9 (PHQ-9), General Anxiety Disorder-7(GAD-7), all-cause mortality, HF hospitalization, major cardiovascular events, and adverse events. The gene discussed is NPPB; the disease is hydrops fetalis.