Anaemia, Polycythaemia and Chronic Heart Failure

Anaemia occurs commonly in chronic heart failure (CHF) and is associated with a poor prognosis. Polycythaemia occurs much less frequently, but two recent large scale studies have also shown it to be associated with a poor prognosis. When defined as haemoglobin less than 12 g/dL for both men and women, as many as 50% of patients hospitalised with CHF are anaemic. The prevalence of anaemia among CHF outpatients is lower (in the region of 15%). Anaemia in heart failure patients is associated with older age, female gender, and greater cardiac dysfunction, renal insufficiency and a history of hypertension. It is likely that anaemia is both a cause and consequence of CHF and a variety of factors may contribute to its development. The most common pattern is that of 'anaemia of chronic disease', although iron deficiency has been reported in up to a fifth of cases. Potential pathophysiological mechanisms include the renal impairment of heart failure, drug side effects, hyporesponsiveness to erythropoietin, haemodilution, and the proinflammatory state of heart failure which causes cytokine-mediated bone marrow suppression. Anaemia is also related to the severity of the heart failure syndrome and has been reported to be an independent risk factor for mortality. Treatment of anaemia with erythropoietin and intravenous iron therapy has been shown to ameliorate the anaemia and to improve symptoms and functional capacity. Anaemia is a potentially reversible risk factor in CHF. Large scale clinical trials are needed to determine whether treatment improves long term survival and what the target haemoglobin should be.