Anemia in acute and chronic heart failure
Although anemia is common in heart failure, controversy remains about whether its high prevalence in heart failure patients is directly related to heart failure itself or other comorbid conditions. In general, anemia is common in patients with chronic medical disorders, including heart failure. Both heart failure and anemia are diseases of the elderly.8 Multiple comorbid conditions are common in heart failure patients, particularly renal insufficiency, which is closely associated with the development of anemia.9, 10 This raises the question of whether the high prevalence of anemia in heart failure patients is due to a direct effect or simply overlapping patient populations. Multiple potential mechanistic links between heart failure and anemia do exist. These include hemodilution, renal dysfunction, proinflammatory cytokines, malnutrition due to right-sided heart failure, decreased perfusion to the bone marrow, and drug therapy, such as angiotensin-converting enzyme (ACE) inhibitors. Realistically, it is likely that several of these mechanisms are active simultaneously, and that anemia in heart failure is the result of a complex interaction between cardiac performance, neurohormonal and inflammatory activation, renal function, and bone marrow responsiveness. This interplay has been termed the “cardio-renal-anemia syndrome.”11 A conceptual model for these interactions is shown in Figure 18.1. Notably, all these mechanisms could be Table 18.1. Prevalence of anemia in selected heart failure studies potentially operative in both acute and chronic heart failure.
