Whilst the prognosis for patients with chronic heart failure (CHF) has improved over the last two decades, many patients suffer with severe limitation from symptoms and adverse prognosis. Heart failure is the most common cause of admission to hospital in people over 65 years in the developed world, and accounts for around 2% of the UK healthcare budget. Low haemoglobin is a common finding in patients with CHF. Although this observation was made several decades ago, the potential of an important pathophysiological link only recently became widely appreciated. While the cause of anaemia is not always easily identified, it is associated with the severity of heart failure, impairment of renal function, and other co-morbidities. Multifactorial aetiology of such anaemia is likely, and although few patients have a deficiency of vitamin B12 or folate this should always be excluded. Anaemia is an independent predictor of mortality and of acute hospital admission, and is also associated with exercise limitation.
Correction of anaemia is, therefore, an appealing strategy. Whilst erythropoietin levels may be elevated in CHF, they are often lower than expected when considering the haemoglobin concentration, indicating a relative deficiency. Similarly, iron metabolism is frequently disturbed, with many patients experiencing either an absolute or functional deficiency. Chronic iron deficiency may contribute to breathlessness and reduced exercise capacity, the hallmarks of symptomatic CHF.
This supplement aims to increase awareness of anaemia in CHF and also to provide an overview of recent studies of erythropoiesis-stimulating agents (ESAs) and of intravenous iron therapy. Recent data from trials of ESAs in chronic kidney disease have highlighted potential detrimental effects on cardiovascular end points and reinforce the need for a major outcome study in CHF. We do not yet know whether correction of iron deficiency can favourably improve survival in CHF; however, observed improvements in New York Heart Association functional class, quality of life, exercise capability, and possibly in hospital admissions, suggest that iron replacement warrants further therapeutic investigation.
The round table meeting brought together specialists from a number of key disciplines (cardiology, nephrology, haematology and elderly care). This facilitated a consensus viewpoint for strategies for the investigation and treatment of anaemia in CHF. We believe that the proposed algorithm (see page S15) will allow a platform for further discussion and provide the basis for treating patients who have severe symptoms despite conventional therapy. We acknowledge that large-scale studies are still needed which incorporate hard end points (mortality and hospitalisation).