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.