To date, RCTs mainly refer to a documented diagnosis of symptomatic HF with typical symptoms/signs of HF combined with LVEF thresholds of ≥ 40%, ≥ 45% or ≥ 50%, evidence of structural heart disease or hospitalization for HF within 12 months, as well as elevated NT-proBNP threshold. The gene discussed is NPPB; the disease is hydrops fetalis.