Prevalence and progression of aortic root dilatation in highly trained young athletes

Objectives: Aortic root dilatation is reported in young athletes; however, it is unclear whether such remodelling is physiological or, whether it represents a potential aortopathy. This observational study investigated the prevalence and progression of aortic root dilatation in young athletes competing at regional or national level.

Methods: Between 2003 and 2015, 3781 athletes aged 19±5.9 years (63.3% male) underwent echocardiography as part of a cardiac screening programme to identify athletes with structural abnormalities. Athletes trained for an average of 16.7 hours per week. Aortic diameter was measured at the level of sinuses of Valsalva. Results were compared with 806 controls. Athletes with an enlarged aortic diameter were followed up for 5±1.5 years.

Results: Athletes revealed a larger mean aortic diameter compared with controls (28.3±4.1 vs 27.8±4.1 mm; p=0.01). The 99th percentile value for aortic diameter in the athlete cohort was defined as the upper limit and was 40 mm in males and 38 mm in females. The aortic diameter measured >40 mm in five male (0.17%) (40-43 mm) and >38 mm in six female (0.4%) (39-41 mm) athletes. During follow-up, none of the athletes with an enlarged aortic diameter showed progressive aortic enlargement compared with the first assessment (40.6±0.9 vs 40.5±0.7 mm in males; (p=0.111) and 38.3±0.6 vs 38.0±0.7 mm in females; (p=0.275)).

Conclusions: A small minority (0.3%) of athletes reveal an enlarged aortic diameter. Medium-term follow-up does not reveal progressive enlargement of the aortic diameter indicative of aortopathy. Longer surveillance studies are necessary to elucidate the precise significance of an enlarged aortic diameter in athletes.