In 31,015 unique patients with EF<40% and HF duration ≥3 months, the median age was 76 (IQR 68–82) years, 27% were female, 50% had NYHA III-IV, and the median NT-proBNP was 2,510 (IQR 999–6,150) pg/mL. This evidence concerns the gene NPPB and hydrops fetalis.