What are the clinical consequences of anemia in patients with chronic heart failure?

Recent studies have drawn cardiologists' attention to the potential impact of anemia in chronic heart failure patients. Cumulative studies show the association between anemia and poorer functional status and increased morbidity and mortality. There are data supporting the association of anemia with worse New York Heart Association functional class, poorer exercise capacity, and increased hospital admission. Anemia has also been shown to be an independent predictor of survival in patients with chronic heart failure. However, the precise pathophysiologic mechanisms by which anemia may increase risk in chronic heart failure are unknown. Similarly, clinicians do not yet have any evidence of whether there is or not a true cause-and-effect relationship between anemia and these parameters. Only intervention studies intended to correct anemia and evaluate the effect on clinical outcomes can verify these important hypotheses.