Epidemiology of anemia in heart failure.

Anemia is being increasingly recognized as an important comorbidity in patients with heart failure. Despite wide variations in defining anemia, approximately one-fifth to one-third of patients with heart failure may experience anemia at a given time. The prevalence may increase to more than half of patients in the setting of severe heart failure, and it may differ with different settings. Meanwhile, up to a fifth of patients may experience new-onset anemia, even though most cases may resolve over time. Different factors contribute to the development of anemia, including increasing age, renal insufficiency, hemodilution, chronic inflammation, and increasing heart failure disease severity.