EDITORIAL Iron i.v. in heart failure: ready for implementation?

This editorial refers to ‘Beneficial effects of long-term intra-venous iron therapy with ferric carboxymaltose in patients with symptomatic heart failure and iron deficiency’, by P. Ponikowski et al. on page doi:10.1093/eurheartj/ehu385 Iron is vital for our health as it plays a crucial role in many processes in the body. Due to its ability to accept and donate electrons, iron is a central part of numerous catalytic enzymes and proteins that are crucial for DNA synthesis, transport of oxygen, cell respiration, oxi-dative phosphorylation, and many other biochemical pathways. Iron is stored within ferritin and, although found in all cells of the body, the liver and the spleen serve as the main sites of ferritin storage. Although ferritin in the serum comprises only a minor part of total ferritin, it is a good indicator of total body iron. In the absence of a physiological excretion mechanism, iron homeostasis is regulated by absorption and recycling. As absorption capacity is limited, los