Correlation between myocardial work indices and main echocardiographic and cardiopulmonary exercise stress test parameters in Olympic endurance athletes

Introduction: Myocardial works indices (MWI) are new echocardiographic parameters that innovatively assess left ventricular function. Although recent studies show correlation between these indices and traditional morpho-functional echocardiographic (TTE) and cardiopulmonary test (CPET) parameters in general population and in different pathologic conditions, data on athletes remains scarce. Aim of our study is to investigate a relationship between MWI and main TTE and CPET parameters in a large cohort of endurance athletes. Methods: We enrolled 306 endurance Olympic athletes, mean age 26.3 ± 4.3 years old, 170 (55.5%) males who underwent clinical and anthropometric evaluation, TTE and CPET. Strain rate and MWI were measured and the following parameters collected: global longitudinal strain (GLS), global myocardial work index (GWI), global constructive myocardial work (GCW), Global Wasted Work (GWW) and global cardiac work efficiency (GWE). Results: MWI showed correlation with peak systolic blood pressure at CPET (GWI, p = 0.012 and GCW, p < 0.0001) and functional TTE parameters such as EF (p = 0.016 for GWI and p = 0.017 for GCW), RV GLS% (p < 0.0001 for GWI and GCW) and LA strain (p < 0.0001 for GWI and GCW). Moreover, MWI were also correlated to echocardiographic heart remodeling parameters, such as LVEDVi (p = 0.046 for GWI) and LVEDDi (p = 0.035 for GWW and p = 0.018 for GWE). MWI correlate also with O2pulse (p = 0.005 for GWI; p = 0.010 for GCW), but not with VO2max/kg. Conclusion: In this study, MWI were associated with cardiac remodeling, but not with VO2 max. It should therefore not be considered as a surrogate marker of an athlete’s training status.