Emerging role of anemia in heart failure.

Current medical therapy of heart failure (HF) focuses primarily on blockade of the neurohormonal pathways. This approach appears to have reached a benefit plateau, despite the introduction of new and improved drugs. Therefore, new targets for pharmacologic intervention are now being actively sought, and anemia has emerged as a potential candidate. Anemia is a frequently occurring comorbidity in patients with HF. However, its true prevalence is difficult to determine because no uniform definition of anemia associated with HF currently exists. Therefore, reported prevalence data can vary significantly, ranging from 4% to 55%, depending on the study population and the applied definition of anemia. Data from recent observational studies and clinical trials suggest that a low hemoglobin concentration in patients with HF is associated with, and is an independent risk factor for, increased morbidity and mortality. In light of these findings, anemia is being discussed as a possible new treatment target in patients with HF. So far, however, only a few small studies have explored this possibility using erythropoiesis-stimulating proteins, which for many years have been successfully used in the treatment of anemia secondary to chronic kidney disease or cancer chemotherapy. Preliminary data from these initial HF studies have shown that increased hemoglobin concentrations in patients with anemia were associated with improvements in cardiac and renal function as well as exercise capacity and a reduced need for hospitalizations. Larger, controlled clinical trials are needed to clearly establish the benefits and safety aspects of anemia treatment on morbidity and possibly mortality in HF patients.