Aims: To assess the prevalence and clinical impact of reductions in the skeletal muscle mass of patients with chronic heart failure (HF). Chronic HF is accompanied by co-morbidities that influence the quality of life and outcomes.
Methods and results: We prospectively enrolled 200 patients with chronic HF. The appendicular skeletal muscle mass of the arms and the legs combined, was assessed by dual energy X-ray absorptiometry. We analysed the muscle strength in arms and legs, and all patients underwent a 6-min walk test, a 4-m walk test, and spiroergometry testing. Muscle wasting was defined as the appendicular muscle mass 2 SD below the mean of a healthy reference group of adults aged 18-40 years, as suggested for the diagnosis of muscle wasting in healthy ageing (sarcopenia). Muscle wasting was detected in 39 (19.5%) subjects. Patients with muscle wasting had significantly lower values for handgrip and quadriceps strength as well as lower total peak oxygen consumption (peakVO2, 1173 ± 433 vs. 1622 ± 456 mL/min), lower exercise time (7.7 ± 3.8 vs. 10.22 ± 3.0 min, both P < 0.001), and lower left ventricular ejection fraction (LVEF, P = 0.05) than patients without. The distance walked during 6 min and the gait speed during the 4-m walk were lower in patients with muscle wasting (both P < 0.05). Serum levels of interleukin-6 were significantly elevated in patients with muscle wasting (P = 0.001). Logistic regression showed muscle wasting to be independently associated with reduced peak VO2 adjusted for age, sex, New York Heart Association class, haemoglobin, LVEF, distance walked in 6 minutes, and the number of co-morbidities (odds ratio 6.53, p = 0.01).
Conclusion: Muscle wasting is a frequent co-morbidity among patients with chronic HF. Patients with muscle wasting present with reduced exercise capacity and muscle strength, and advanced disease.