“…In HF patients, anaemia is probably a marker of: 1) accumulation of factors which are themselves important predictors of unfavourable outcomes in HF (such as older age, malnutrition, frailty, and higher non-cardiac co-morbidity burden, including chronic kidney disease), both by their direct influence and due to our tendency to under-prescribe evidence-based HF therapies in such patients, 2) iron deficiency, which might itself aggravate skeletal and heart muscle dysfunction, and 3) more advanced HF stages because anaemia in severe HF might result from subclinical inflammation (anaemia of chronic disorders) as well as from haemodilution in patients with fluid retention [31,32]. These assumptions are supported by the fact that iron supplementation (in both anaemic and non-anaemic HF patients), but not darbepoetin or erythropoietin treatment, has led to an improvement in functional capacity and a reduction in hospitalisations for symptom deterioration in HF [33][34][35]. The four presented models were chosen because they were derived from the largest cohorts.…”