Cardiac cachexia – Up-to-date 2015

Cachexia is defined as unintended loss of 5% of the original body weight of a patient with edema within 3–12 months in combination with typical symptoms of a chronic disease. Prevalence of cardiac cachexia (CC) in chronic heart failure (CHF) is 5–15%, with an annual mortality rate of 20–30%. The condition involves loss of lean body mass (skeletal muscle), body fat, and, to a lesser extent, also bone tissue. In pathophysiological terms, cachexia is associated with complex alterations in neurohormonal and immunological status, catabolism prevailing over anabolism, and activation of pro-inflammatory cytokines, with the key role played by TNF-α. The pro-inflammatory response is believed to be induced by reduced blood supply to the intestine and intestinal wall edema in the presence of congestion facilitating entry of bacteria and endotoxins into the circulation. Other processes include reduced perfusion of the skeletal muscle, its atrophy, and abnormal myocyte metabolism characterized by depletion of energy-rich substances (loss of ATP, creatine, and glycogen), excess of water and lactate, as well as impaired oxidative metabolism. Research at the level of the “atrophising” muscle cell has focused on the ubiquitin–proteasome system, growth differentiation factor-15, myostatin, and other muscle cell regulatory proteins. Novel biomarkers of CC, anabolism/catabolism, and skeletal muscle status include ghrelin, adiponectin, C-terminal agrin fragment, growth differentiation factor-15, N-terminal propeptide of type III procollagen, myostatin, and D3-creatine estimated using the dilution method. Promising results in the treatment of cachexia have been reported with ghrelin receptor agonists (anamorelin), selective androgen receptor modulators (enobosarm), and some beta-blockers (espindolol); research into myostatin antagonists is under way. Aerobic exercise has been shown to have a beneficial effect. Though recommended, no hard data are currently available to document the value of nutritional support.