ACE Inhibitors and Anemia in Congestive Heart Failure

The use of angiotensin‐converting enzyme inhibitors can be accompanied by a number of adverse events, including cough, angioedema, and hyperkalemia, as well as a peculiar form of functional renal insufficiency. Other, less obvious side effects accompany ACE inhibitor use, such as a reduction in red blood cell production. This feature of ACE inhibitor use may be employed to good effect, as in the management of post‐transplant erythrocytosis. Alternatively, the suppressive effect of ACE inhibitors on red blood cell production may intensify the anemia of chronic renal failure and/or congestive heart failure. The untreated congestive heart failure patient typically has an increased red blood cell mass as a consequence of increased erythropoietin levels, with the latter governed by congestive heart failure‐related renal hypoxia. This is not expressed as an increase in hemoglobin concentration because of the increase in plasma volume that marks advanced congestive heart failure. ACE inhibitor therapy can be expected to both reduce plasma volume and decrease red blood cell production. As a result, the hemoglobin concentration changes very little in the ACE inhibitor‐treated congestive heart failure patient and usually falls in the low normal range. Recently, erythropoietin has been employed to good effect in congestive heart failure patients with borderline anemia.