A meta-analysis of aortic root size in elite athletes.

BACKGROUND The aorta is exposed to hemodynamic stress during exercise, but whether or not the aorta is larger in athletes is not clear. We performed a systematic literature review and meta-analysis to examine whethere athletes demonstrate increased aortic root dimensions compared with nonathlete controls. METHODS AND RESULTS We searched MEDLINE and Scopus from inception through August 12, 2012, for English-language studies reporting the aortic root size in elite athletes. Two investigators independently extracted athlete and study characteristics. A multivariate linear mixed model was used to conduct meta-regression analyses. We identified 71 studies reporting aortic root dimensions in 8564 unique athletes, but only 23 of these studies met our criteria by reporting aortic root dimensions at the aortic valve annulus or sinus of Valsalva in elite athletes (n=5580). Athletes were compared directly with controls (n=727) in 13 studies. On meta-regression, the weighted mean aortic root diameter measured at the sinuses of Valsalva was 3.2 mm (P=0.02) larger in athletes than in the nonathletic controls, whereas aortic root size at the aortic valve annulus was 1.6 mm (P=0.04) greater in athletes than in controls. CONCLUSIONS Elite athletes have a small but significantly larger aortic root diameter at the sinuses of Valsalva and aortic valve annulus, but this difference is minor and clinically insignificant. Clinicians evaluating athletes should know that marked aortic root dilatation likely represents a pathological process and not a physiological adaptation to exercise.