The purpose of this study is to determine whether increasing hemoglobin concentration in patients with heart failure and anemia will improve the patients' functional status, including exercise tolerance and New York Heart Association (NYHA) classification.

Inclusion Criteria: - At least 21 years of age - Symptomatic CHF for at least 3 months - Limited exercise tolerance on a treadmill - Reduced left ventricular ejection fraction - Stable heart failure medication - Hemoglobin concentration between 9.0 and 12.5 g/dL Exclusion Criteria: - Hypertension - Unstable angina pectoris or recent myocardial infarction - Likely to receive cardiac transplant - Unable to do cardiopulmonary exercise testing - Major organ transplant (e.g., lung, liver, heart) or in renal replacement therapy (e.g., dialysis) - Recent or current treatment for malignancy - Systemic hematologic disease - Anemia due to acute or chronic bleeding - Recent epogen or darbepoetin alfa therapy - Recent blood transfusion