Piecing together the evidence on anemia: the link between chronic kidney disease and cardiovascular disease.

Chronic kidney disease (CKD) is now accepted as an independent cardiovascular disease (CVD)-risk state, regardless of its underlying cause. Anemia is a common feature of CKD, particularly in end-stage renal disease. Anemia is also independently associated with poorer outcomes in a wide variety of CVD states, including congestive heart failure and coronary artery disease. Anemia appears to act as an independent mortality multiplier when hemoglobin levels drop below 12 g/dL. With the independent and profound contribution of both CKD and anemia to cardiovascular mortality and morbidity, understanding the pathophysiologic links among these disease states is important. In addition, it is hoped that treatments currently under active investigation and geared specifically to attenuate the cardiovascular risk associated with anemia and CKD, such as erythropoietin therapy, will improve outcomes. This article reviews the evidence for an association among CKD, anemia, and CVD.