Of particular note, when rising RDW and discharge RDW >15% were added to a prognostic model including well-established HF prognostic markers (age, LVEF, Hb, creatinine, NT-pro BNP, and hemoconcentration), the capacity of the model to reclassify patients with and without event was significantly improved. The gene discussed is NPPB; the disease is hydrops fetalis.