Metabolic and nutritional disorders in cardiac cachexia

Cardiac cachexia is divided into two types, i.e., the classic type, which occurs in patients with severe heart failure, and the nosocomial type, which develops in the postoperative state. Cardiac cachexia is due both to a decrease in nutrient intake (anorexia, malabsorption) and to specific metabolic alterations (hypercatabolism with increased energy expenditure, response to hypoxia, inflammatory status, etc). Among the various mechanisms involved in the pathogenesis of cachexia, cellular hypoxia has long been recognized. The chronic activation of the endogenous neurohormonal system is another specific feature of such patients; a striking relationship was found between cardiac cachexia and hormonal levels which correlate better than the classical parameters of cardiac failure severity. Finally, inflammatory syndrome has been known to occur frequently in patients with cardiac cachexia. Several studies have shown that tumor necrosis factor-α was significantly increased in cachectic patients and that chronic activation of the systemic immune response might be a common and unifying factor.