Abstract
Regular physical exercise is undoubtedly associated with cardiovascular health benefit, increased longevity, and improved endurance performance. Competitive endurance athletes exceed the recommended exercise dose, which lead to pathologic cardiac remodeling such as myocardial fibrosis. This review examines the impact of myocardial fibrosis on atrial and ventricular structures and functions in endurance athletes. A systematic literature search identified eight trials that enrolled 470 athletes. The prevalence of myocardial fibrosis ranged from 13% to 48%, which was commonly of a focal nonischemic pattern. The included studies did not find consistent results on the impact of myocardial fibrosis on ventricular function and volume parameters. Moreover, the prognostic implications of myocardial fibrosis on patient clinical outcomes, such as arrhythmias and mortality, were not reported as there was no long-term follow-up. There is a clear unmet need to encourage larger studies on myocardial fibrosis phenotypes to shed more light on the underlying mechanism, clinical consequences, and prognosis.