Exercise Physiology 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; 99th percentile 40 mm); in females, aortic root was 27.5 2.6 mm (range, 20 to 36; 99th percentile 34 mm). Aortic root was enlarged 40 mm in 17 male (1.3%) and 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 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. (Circulation. 2010;122:698-706.)