Myocardial Work Index in Professional Football Players: A Novel Method for Assessment of Cardiac Adaptation

Background: The global myocardial work index (GWI), a novel, valid, and non-invasive method based on speckle-tracking echocardiography, could provide value for calculating left ventricular (LV) function and energy consumption in athletes. Materials and Methods: We prospectively analyzed a single-center cohort of Spanish First-Division football players who attended a pre-participation screening program from June 2020 to June 2021, compared to a control group. All the individuals underwent an electrocardiogram and echocardiography, including two-dimensional speckle tracking and 4D-echo. The study aimed to evaluate the feasibility of myocardial work in professional football players and its correlations with other echocardiographic parameters. Results: The study population comprised 97 individuals (49 professional players and 48 controls). The mean age was 30.48 ± 7.20 years old. The professional football players had significantly higher values of LVEDV (p < 0.001), LVESV (p < 0.001), LV-mass index (p = 0.011), PWTd (p = 0.023), and EA (p < 0.001) compared with the control group. In addition, the professional players had lower GCW (p = 0.003) and a tendency to show lower GWI values (p < 0.001). These findings could suggest that professional football players have more remodeling and less MW, related to their adaptation to intensive training. Significant differences in GLS (p = 0.01) and GWE (p = 0.04) were observed as a function of the septal thickness of the athletes. Irrespective of the MW variable, the parameters with better correlations across all the populations were SBP, DBP, and GLS. Conclusions: The GWI is a novel index to assess cardiac performance, with less load dependency than strain measurements. Future GWI analyses are warranted to understand myocardial deformation and other pathological differential diagnoses.