Skeletal Muscle Mass in Elderly Heart Failure Patients; Comparison between Systolic and Diastolic Heart Failure and Corresponding Significance in Exercise Capacity

Background: Exercise intolerance is a common symptom of heart failure and has a detrimental impact on the quality of life. Skeletal muscle atrophy has been considered an important contributor to exercise intolerance; however, most studies have been conducted in patients with advanced systolic heart failure. Methods: We studied 39 ambulatory heart failure patients (age, 77.9 +/- 6.5; male, 17[43.6%]) and 39 age and gender-matched, community-dwelling, elderly subjects. Clinical, laboratory, and echocardiographic evaluations were performed. Dual-energy X-ray absorptiometry was performed to assess the body composition. Exercise capacity was measured by a six-minute walk test. Comprehensive geriatric assessments were also performed to evaluate comorbidity, medication, physical function, cognitive function, and nutritional status. Results: Skeletal muscle mass of heart failure patients showed no differences when compared with that of age- and gender-matched control subjects in any part of the body or in the whole body. Although diastolic heart failure patients showed lower levels of skeletal muscle mass than systolic heart failure patients, no significant difference was identified in either systolic or diastolic heart failure patients compared with respective age- and gender-matched control groups. The six-minute walk distances showed no difference between the groups (257.2 +/- 117.8 m in the diastolic heart failure group versus 302.7 +/- 109.4 m in the systolic heart failure group, p=0.226). Conclusion: Although skeletal muscle mass has been known to be an independent factor associated with exercise capacity in advanced heart failure patients, skeletal muscle mass was not decreased in ambulatory, elderly heart failure patients when comparing age- and gender-matched control subjects.