Association Between Locomotor Muscle Quality and Cardiac Function During Exercise in Heart Failure with Preserved Ejection Fraction

Aims Muscle quality (MQ) is used to assess skeletal muscle function; however, the relationship between MQ and cardiac function during exercise in heart failure with preserved ejection fraction (HFpEF) is unknown. Therefore, the study aimed to determine the relationship between locomotor MQ and cardiac function during exercise in HFpEF. Methods and results A total of 22 HFpEF patients and 23 healthy matched controls (CTL) were recruited. Body composition including leg lean mass percentage (LL%) was measured by dual-energy X-ray absorptiometry. Cardiopulmonary exercise testing was performed and peak oxygen uptake (VO2) was measured. Cardiac output (CO) was measured via the open-circuit acetylene wash-in technique, heart rate by electrocardiogram, and cardiac power output (CPO) was calculated. Blood pressure was measured manually and mean arterial pressure (MAP) was calculated. MQ was calculated as peak watts divided by LL%. LL% was significantly lower in HFpEF than in CTL (p < 0.05). At peak exercise, workload, VO2, CO, and CPO were significantly lower in HFpEF (p < 0.05 for all). MQ was significantly lower in HFpEF than in CTL (1.6 ± 0.4 vs. 2.3 ± 0.6 W/%, p < 0.0001). MQ was positively correlated with CO (r = 0.51), CPO (r = 0.72) and MAP (r = 0.64) in HFpEF (p < 0.05 for all) but not in CTL. Conclusion Our data suggest MQ is closely related to cardiac function at peak exercise in HFpEF. These data suggest that MQ may be a useful tool for understanding exercise performance in HFpEF.