GSTM1 and hydrops fetalis: The first RCT exploring the use of IV iron in HF patients was conducted in 2007 by Toblli et al. in 40 HF patients with iron deficiency anaemia (defined as a Hb of < 12.5 g/dL in men and < 11.5 g/dL in women), in addition to a LVEF of ≤ 35% and serum ferritin of < 100 ng/ml and/or with transferrin saturation (TSAT) ≤ 20%.