Enhanced Echo Intensity of Skeletal Muscle Is Associated with Exercise Intolerance in Patients with Heart Failure

Abstract Background Skeletal muscle is quantitively and qualitatively impaired in patients with heart failure (HF), which is closely linked to lowered exercise capacity. Ultrasonography (US) for skeletal muscle has emerged as a useful, noninvasive tool to evaluate muscle quality and quantity. Here we investigated whether muscle quality based on US-derived echo intensity (EI) is associated with exercise capacity in patients with HF. Methods and Results Fifty-eight patients with HF (61 ± 12 years) and 28 control subjects (58 ± 14 years) were studied. The quadriceps femoris echo intensity (QEI) was significantly higher and the quadriceps femoris muscle thickness (QMT) was significantly lower in the HF patients than the controls (88.3 ± 13.4 vs. 81.1 ± 7.5, p=0.010; 5.21 ± 1.10 vs. 6.54 ±1.34 cm, p Conclusion Enhanced echo intensity in skeletal muscle was independently associated with lowered exercise capacity in HF. The measurement of EI is low-cost, easily accessible, and suitable for assessment of HF-related alterations in skeletal muscle quality.