Currently, iron levels are typically investigated only after CHF patients are found to have anaemia. But Piotr Ponikowski from the Medical University of Wroclaw, Poland, argued that iron deficiency in heart failure may not necessarily be linked to anaemia, and needs to be assessed for all CHF patients. ‘New studies are showing that the presence of iron deficiency seems to be independently associated with severity of CHF symptoms - including exercise intolerance - and constitutes both a sign of poor outcome and a target for treatment,’ said Ponikowski.
I ron is known to play a key role in human homeostasis. It is essential for growth and required for erythropoiesis, oxygen transport and storage, oxidative metabolism in skeletal and heart muscle, and the synthesis and degradation of lipids, carbohydrates, DNA and RNA. Iron deficiency is a commonly occurring nutritional disorder that affects more than one-third of the population and complicates chronic diseases such as inflammatory bowel disease, Parkinson’s disease and rheumatoid arthritis. Traditionally, iron deficiency has been linked with the presence of anaemia in CHF, with the reported prevalence varying between 20 and 70% of all heart failure patients. However, a recent study by Ewa Jankowska, also at the Wroclaw Medical University, investigating the iron status of 546 patients with CHF, found iron deficiency among those both with and without anaemia. Overall, 37% of subjects had iron deficiency, 57% of those with anaemia and 32% without. The study furthermore showed that that iron deficiency was a key determinant of outcome, with a multivariant analysis, undertaken after a mean follow-up of two years, showing that iron deficiency (but not anaemia) was related to an increased risk of death or heart transplantation (adjusted HR 1.58, p<0.01)
L ast year, the Ferinject (R) Assessment in Patients with Iron Deficiency and Chronic Heart Failure (FAIR -HF) study by Stefan Anker from Charite Universitatsmedizin Berlin showed that intravenous iron therapy given to CHF patients has the ability to improve functional capacity, exercise tolerance and quality of life (N Eng J Med 2009; 361: 2436-2448). In the study, 459 patients with NYHA class II /III were randomised to i.v. iron (200 mg i.v. in the correction phase, followed by 200 mg i.v. iron every four weeks in the maintenance phase) (n=304) or placebo consisting of normal saline (n=155). R esults showed that among patients receiving intravenous iron 50% reported being much or moderately improved on the self-reported Patient Global Assessment (PGA )score, compared with 28% receiving placebo (p<0.0001). At week 24, among the patients assigned to iron, 47% had an NYHA functional class I or II in comparison with 30% assigned to placebo (p<0.0001). Furthermore, after 24 weeks patients receiving intravenous iron were able to walk 39 metres further than at baseline in the six-minute walk test compared to 9 metres in the placebo group (p<0.001). Mortality and rates of adverse events including hospitalisations were similar for both groups.
T he study showed that patients with anaemia, defined by a haemoglobin level of 120 mg/L or less, were no more likely to derive benefit for symptoms or functional improvements than those without anaemia.