The influence of muscle mass, strength, fatigability and blood flow on exercise capacity in cachectic and non-cachectic patients with chronic heart failure

Abstract

The influence of age, skeletal muscle function and peripheral blood flow on exercise capacity in chronic heart failure patients is controversial, possibly due to variations in skeletal muscle atrophy. To assess predictors of exercise capacity in patients with clinical cardiac cachexia, we studied 16 cachectic and 39 non-cachectic male chronic heart failure patients of similar age and ejection fraction. All cachectic patients were wasted (% ideal body weight: 81 1·9 vs 105·2±2·1, P−1, min ⁻¹, resting, and peak blood flow (plethysmography) and 20 min fatigability (% baseline strength) were all similar between the two groups. Quadriceps strength, muscle size (all PPPPR=0·43, all PP0·005), whereas age and strength did not. Similar findings were confirmed using other previously published definitions of cardiac cachexia. The predictors of exercise capacity change with the development of cardiac cachexia from age and strength to peak blood flow. This shift may be caused by additional endocrine or catabolic abnormalities active in end stage heart failure.