Impact of whole-body and skeletal muscle composition on peak oxygen uptake in heart failure: a systematic review and meta-analysis.

Aims: Heart failure (HF) has a major impact on exercise tolerance that may (in part) be due to abnormalities in body and skeletal muscle composition. This systematic review and meta-analysis aims to assess how differences in whole-body and skeletal muscle composition between patients with HF and non-HF controls (CON) contribute to reduced peak oxygen uptake (VO₂peak).

Methods and results: The PubMed database was searched from 1975 to May 2024 for eligible studies. Cross-sectional studies with measures of VO₂peak, body composition, or muscle biopsies in HF and CON were considered. Out of 709 articles, 27 studies were included in this analysis. Compared with CON, VO₂peak [weighted mean difference (WMD): -9.96 mL/kg/min, 95% confidence interval (CI): -11.71 to -8.21), total body lean mass (WMD: -1.63 kg, 95% CI: -3.05 to -0.21), leg lean mass (WMD: -1.38 kg, 95% CI: -2.18 to -0.59), thigh skeletal muscle area (WMD: -10.88 cm² , 95% CI: -21.40 to -0.37), Type I fibres (WMD: -7.76%, 95% CI: -14.81 to -0.71), and capillary-to-fibre ratio (WMD: -0.27, 95% CI: -0.50 to -0.03) were significantly lower in HF. Total body fat mass (WMD: 3.34 kg, 95% CI: 0.35-6.34), leg fat mass (WMD: 1.37 kg, 95% CI: 0.37-2.37), and Type IIx fibres (WMD: 7.72%, 95% CI: 1.52-13.91) were significantly higher in HF compared with CON. Absolute VO₂peak was significantly associated with total body and leg lean mass, thigh skeletal muscle area, and capillary-to-fibre ratio.

Conclusion: Individuals with HF display abnormalities in body and skeletal muscle composition including reduced lean mass, oxidative Type I fibres, and capillary-to-fibre ratio that negatively impact VO₂peak.