Class II-III chronic heart failure was associated with a significant reduction in skeletal muscle capillary density compared to healthy controls (1.42 vs. 1.74 endothelial cells/fiber, p=0.02).
Cross-Sectional (n=32)
Yes
Does capillary density of skeletal muscle differ between patients with class II-III CHF and normal controls, and does it correlate with exercise intolerance?
A reduction in skeletal muscle microvascular density may precede other skeletal muscle alterations and play a critical role in the exercise intolerance characteristic of patients with chronic heart failure.
Absolute Event Rate: 1.42% vs 1.74%
p-value: p=0.02
OBJECTIVES: The study was conducted to determine if the capillary density of skeletal muscle is a potential contributor to exercise intolerance in class II-III chronic heart failure (CHF). BACKGROUND: Previous studies suggest that abnormalities in skeletal muscle histology, contractile protein content and enzymology contribute to exercise intolerance in CHF. METHODS: The present study examined skeletal muscle biopsies from 22 male patients with CHF compared with 10 age-matched normal male control patients. Aerobic capacities, myosin heavy chain (MHC) isoforms, enzymes, and capillary density were measured. RESULTS: The patients with CHF demonstrated a reduced peak oxygen consumption when compared to controls (15.0+/-2.5 vs. 19.8+/-5.0 ml x kg(-1) x min(-1), p <0.05). Using cell-specific antibodies to directly assess vascular density, there was a reduction in capillary density in CHF measured as the number of endothelial cells/fiber (1.42+/-0.28 vs. 1.74+/-0.35, p = 0.02). In CHF, capillary density was inversely related to maximal oxygen consumption (r = 0.479, p = 0.02). The MHC IIx isoform was found to be higher in patients with CHF versus normal subjects (28.5+/-13.6 vs. 19.5+/-9.4, p <0.05). CONCLUSIONS: There was a significant reduction in microvascular density in patients with CHF compared with the control group, without major differences in other usual histologic and biochemical aerobic markers. The inverse relationship with peak oxygen consumption seen in the CHF group suggests that a reduction in microvascular density of skeletal muscle may precede other skeletal muscle alterations and play a critical role in the exercise intolerance characteristic of patients with CHF.
Duscha et al. (1999) conducted a cross-sectional in Class II-III chronic heart failure (n=32). Class II-III chronic heart failure vs. Age-matched healthy sedentary males was evaluated on Capillary density (endothelial cells/muscle fiber) (p=0.02). Class II-III chronic heart failure was associated with a significant reduction in skeletal muscle capillary density compared to healthy controls (1.42 vs. 1.74 endothelial cells/fiber, p=0.02).