Assessment of left ventricular systolic function using a non-invasive index of myocardial work in amateur marathon runners.

Background: For non-professionally trained athletes, the hyperphysiological stress response induced by marathon exercise may lead to heart fatigue and even cause organic changes such as abnormal ventricular septal thickening. Early detection of abnormal cardiac function in athletes can help prevent adverse cardiovascular events. The purpose of this study was to analyze the left ventricular systolic function (LVSF) of amateur marathon runners using a novel technique called the left ventricular (LV) pressure-strain loop (PSL). Methods: A total of 35 amateur marathon runners and 33 age-matched healthy controls from Hangzhou were enrolled in this cross-sectional study from October 2021 to August 2023. The LV myocardial work (MW) parameters were calculated as the area of the PSL by two-dimensional speckle-tracking echocardiography (2D-STE) and blood pressure. The differences between the structural and functional data of the two groups and the predictive efficacy of each of the MW parameters for LV systolic function were analyzed using receiver operating characteristic (ROC) curves. The correlations between the PSL parameters and conventional echocardiographic parameters were analyzed. Results: Global wasted work (GWW) was higher and global work efficiency (GWE) was lower in the amateur marathon runner group than the control group (P<0.05). The ROC curve analysis showed that the maximum area under the curve (AUC) for GWE was 0.681 [95% confidence interval (CI): 0.551-0.812] with an optimal cut-off value of 96.14%, and a sensitivity and specificity of 75.8% and 62.9%, respectively. The correlation analysis results showed that GCW was associated with increased diastolic interventricular septal thickness (IVSTd) (P<0.05, r=0.379). GWE was related to all conventional echocardiography parameters (P<0.05, r=-0.416, -0.674, -0.393, 0.406, 0.502, and -0.424, respectively). While GWW was correlated with increased IVSTd, LV diastolic posterior wall thickness (LVPWTd), and decreased global longitudinal strain (GLS) (all P<0.05, r=0.352, 0.395, and -0.344, respectively). Conclusions: Amateur marathon runners show potential changes in cardiac structure and systolic function after a period of endurance exercise, which can be assessed using non-invasive MW to evaluate LVSF. LV MW, which incorporates the GLS and afterload conditions, is more sensitive than GLS, and has emerged as a promising parameter for LV systolic functional evaluation.