Aortic Stiffness and Distensibility in Top-Level Athletes

Background: Although cardiac adaptation to different sports has been extensively described, the potential relationship of training with aortic root (AR) elastic properties and diameters in top-level athletes remains not fully investigated. The aims of this study were to compare AR morphology and stiffness between highly trained athletes and sedentary subjects and to assess the independent determinants of AR stiffness and distensibility in athletes. Methods: Four hundred ten elite athletes (220 endurance-trained athletes [ATE] and 190 strength-trained athletes [ATS]; 290 men; mean age, 28.3 +/- 13.6 years; age range, 18-40 years) and 240 healthy controls underwent standardized comprehensive transthoracic echocardiography, including Doppler studies. End-diastolic AR diameters were measured at four locations: the aortic annulus, the sinuses of Valsalva, the sinotubular junction, and the maximal diameter of the proximal ascending aorta. The aortic distensibility index was calculated as 2 x (systolic proximal ascending aortic diameter - diastolic proximal ascending aortic diameter)/(diastolic proximal ascending aortic diameter) x (pulse pressure) (cm(-2) . dyn(-1) . 10(-6)). AR stiffness index was defined as (systolic blood pressure/diastolic blood pressure)/(systolic proximal ascending aortic diameter - diastolic proximal ascending aortic diameter)/diastolic proximal ascending aortic diameter. Analysis of variance was performed to evaluate differences among groups. Results: Left ventricular (LV) mass index did not significantly differ between the two groups of athletes but was lower incontrols. ATS showed higher body surface area, sum of wall thickness (septum plus LV posterior wall), and circumferential end-systolic stress, while LV stroke volume and LV end-diastolic volume were greater in ATE. AR diameters at all levels and AR stiffness were significantly greater in ATS than in ATE and controls, while AR distensibility was significantly higher in ATE. However, AR dilatation was observed only in four male power athletes (1%). By multivariate analyses, in the overall population of athletes, age, LV stroke volume, endurance training, and duration of training were the only independent determinant of higher AR distensibility. On the other hand, age, circumferential end-systolic stress, strength training, and duration of training were independently associated with AR stiffness in ATS. Conclusions: AR diameters and stiffness were significantly greater in strength-trained athletes, while aortic distensibility was higher in endurance athletes compared with age-and sex-matched healthy controls. (J Am Soc Echocardiogr 2012;25:561-7.)