The main mechanisms of anemia in patients with heart failure are renal dysfunction, increased sympathetic and renin-angiotensin-aldosterone activity, hemodilution, absolute or functional iron deficiency, impaired erythropoietin production and activity, activation of the inflammatory cascade, angiotensin converting enzyme inhibition and angiotensin receptor blockade, and vitamin B12 and folic acid deficiency (Figure 1). Here, EPO is linked to heart failure.