Skeletal Muscle Energetics in Heart Failure Assessed Using 31P Magnetic Resonance Spectroscopy—A Systematic Review and Meta-Analysis

Introduction: Skeletal muscle (SkM) abnormalities are well-recognised in heart failure (HF). We aimed to systematically review studies of SkM energetics in patients with HF at rest and post-exercise using 31phosphorus magnetic resonance spectroscopy (31P MRS). Methods: A systematic search of cross-sectional studies used predefined search terms related to HF, SkM energetics, and 31P MRS (PROSPERO ID: CRD42023434698). Inclusion criteria for studies are as follows: 1. HF participants versus controls; and 2. SkM energetics assessed using 31P MRS reporting BOTH (i) PCr recovery time and (ii) PCr ratios (PCr/Pi and/or PCr/ATP). The primary outcome was SkM PCr recovery time following exercise, comparing patients with diagnosed HF and healthy controls and reported as standardised mean difference (SMD). Results: Of 465 identified studies, 6 met the inclusion criteria and were conducted from 1987 to 2021, comprising 162 participants (N = 86 HF, N = 76 healthy controls). HF patients (mean age 55.1 ± 4.16 years, 49 (56.9%) male) were reasonably matched to healthy controls (mean age 50 ± 8.9 years, 54 (71%) males). Two studies did not report patients’ ejection fractions (EF); the mean EF among patients from the remaining six studies was 24.8%. No studies specifically included participants with HFpEF and none characterised sarcopenia. HF patients exhibited impaired SkM energetics compared to healthy controls, which were characterised by a significantly increased PCr recovery time (SMD: −1.35, CI: −2.11, −0.59). Conclusions: PCr recovery is significantly impaired in patients with HFrEF. Females were under-represented, no HFpEF studies were identified, and no studies linking abnormal SkM energetics directly to sarcopenia were identified.