Patients enrolled in IRONMAN9 were older compared with those in many previous trials of intravenous iron in HF,6, 8, 13 with a mean age of 73 years and a quarter aged >79 years, closely resembling contemporary patients encountered in routine clinical practice.14 Our analysis shows no evidence of attenuation of the effects of FDI on major clinical outcomes, QoL or Hb concentrations in older patients. The gene discussed is GSTM1; the disease is hydrops fetalis.