Aortic regurgitation in athletes: the challenges of echocardiographic interpretation

Background: Bicuspid aortic valve (BAV) is the most common congenital cardiac defect and prone to premature degeneration causing aortic regurgitation (AR). The assessment of AR in athletic individuals poses several challenges as the pathological left ventricle (LV) remodelling caused by AR may overlap with the physiological remodelling of intense exercise. The purpose of this study is to highlight these challenges, review the existing literature and discuss how to tackle these conundrums. As a real-world example, we compare the resting transthoracic echocardiographic (TTE) findings in a cohort of individuals with BAV and AR, sub-grouped into "highly active" or "lightly active".

Methods: Adult male subjects with an index TTE performed at a tertiary referral centre between 2019 and 2022 were included if the TTE confirmed a BAV and at least moderate AR. Further strict inclusion criteria were applied and parameters of valve disease severity was made in accordance with existing guidelines. Subjects completed a physical activity questionnaire over the telephone, and were classified into either group 1: "highly active" or group 2: "lightly active" based on their answers. Demographics and TTE parameters were compared between the two groups.

Results: 30 male subjects (mean age 44 ± 13 years) with BAV-AR were included - 17 were highly active, and 13 lightly active. There was no significant difference in age (group 1, 45 ± 12.7 years vs. group 2, 42 ± 17 years; p = 0.49), height (p = 0.45), weight (p = 0.268) or severity of AR, when quantitative assessment was possible. Group 1 had a significantly higher stroke volume (131 ± 17mls vs. 102 ± 13 mls; p = 0.027), larger LV volumes, diastolic dimensions and significantly larger bi-atrial and right ventricular size. This LV dilatation in the context of AR and athleticism poses a diagnostic and management conundrum. Despite this, none of these 17 highly active individuals demonstrated any of the traditional criteria used to consider surgery.

Conclusion: There is significant overlap between the physiological adaptations to exercise and those caused by AR. Multi-modality imaging and stress testing can aid clinicians in diagnostic and management decisions in exercising individuals when there is discordance between AR severity and symptoms.