This is a randomised, double-blind, placebo-controlled Trial (RCT). The 52 weeks observation period following randomisation is considered appropriate to investigate the primary endpoint of recurrent HF hospitalisations and CV death. To evaluate the effect of intravenous ferric carboxymaltose (IV FCM) in iron deficient subjects with AHF, subjects will be enrolled during a hospital stay (Index hospitalisation) after the acute care treatment of the index event has been stabilised. All subjects will continue to receive their established standard therapy for HF and medical emergencies will be treated according to local routine.