Prevalence and clinical significance of aortic root dilation in highly trained competitive athletes.

BACKGROUND Few data are available that address the impact of athletic training on aortic root size. We investigated the distribution, determinants, and clinical significance of aortic root dimension in a large population of highly trained athletes. METHODS AND RESULTS Transverse aortic dimensions were assessed in 2317 athletes (56% male), free of cardiovascular disease, aged 24.8+/-6.1 (range, 9 to 59) years, engaged in 28 sports disciplines (28% participated in Olympic Games). In males, aortic root was 32.2+/-2.7 mm (range, 23 to 44; 99 th percentile=40 mm); in females, aortic root was 27.5+/-2.6 mm (range, 20 to 36; 99 th percentile=34 mm). Aortic root was enlarged >or=40 mm in 17 male (1.3%) and >or=34 mm in 10 female (0.9%) subjects. Over an 8-year follow-up period, aortic dimension increased in these male athletes (40.9+/-1.3 to 42.9+/-3.6 mm; P<0.01) and dilated substantially (to 50, 50, and 48 mm) in 3, after 15 to 17 years of follow-up, in the absence of systemic disease. Aortic root did not increase significantly (34.9+/-0.9 to 35.4+/-2.1 mm; P=0.11) in female athletes. Multiple regression and covariance analysis showed that aortic dimension was largely explained by weight, height, left ventricular mass, and age (R(2)=0.63; P<0.001), with type of sports training having a significant but lower impact (P<0.003). CONCLUSIONS An aortic root dimension >40 mm in highly conditioned male athletes (and >34 mm in female athletes) is uncommon, is unlikely to represent the physiological consequence of exercise training, and is most likely an expression of a pathological condition, mandating close clinical surveillance.