Abstract 11575: A Meta-analysis of Aortic Root Size in Athletes

Abstract

Background: Exercise training induces cardiac remodeling and increases cardiac dimensions in athletes. The aorta is also 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 if athletes demonstrate increased aortic root dimensions when compared to non-athlete controls.

Methods: We searched MEDLINE and EMBASE from inception through April 2012 for English-language studies reporting the aortic root size in athletes. Additional references were obtained from bibliographies of identified articles. Two investigators independently extracted athlete and study characteristics. A multivariate linear mixed model was used to conduct meta-regression analyses.

Results: We identified 71 studies reporting aortic root dimensions in 8541 athletes and 1878 controls. Athletes were directly compared to controls in 49 studies. The pooled athletic cohort included 3294 endurance-trained athletes, 668 strength-trained athletes, 402 combined endurance- and strength-trained athletes and 3737 athletes, in whom pure classification was not possible. Upon meta-regression, the weighted mean aortic root diameter in athletes overall was 1.87 mm larger than in the non-athletic controls (p < 0.001). Subgroup analysis demonstrated that aortic root diameter in endurance-trained athletes was 2.49 mm larger than controls (p < 0.0001), but the difference in aortic root size between strength-trained athletes and controls was only 1.19 mm and not statistically significant (p = 0.15).

Conclusion: Endurance exercise training is associated with small, but significant increases in aortic diameter, whereas strength training is not associated with significant changes in aortic diameter. Marked enlargement of the aorta in athletes should not be attributed to athletic activity.