Spectrum of Aortic Valve Abnormalities Associated with Aortic Dilation Across Age Groups in Turner Syndrome

Background: Congenital aortic valve fusion is associated with aortic dilation, aneurysm, and rupture in girls and women with Turner syndrome. Our objective was to characterize aortic valve structure in subjects with Turner syndrome and to determine the prevalence of aortic dilation and valve dysfunction associated with different types of aortic valves.

Methods And Results: The aortic valve and thoracic aorta were characterized by cardiovascular MRI in 208 subjects with Turner syndrome in an institutional review board-approved natural history study. Echocardiography was used to measure peak velocities across the aortic valve and the degree of aortic regurgitation. Four distinct valve morphologies were identified: tricuspid aortic valve, 64% (n=133); partially fused aortic valve, 12% (n=25); bicuspid aortic valve, 23% (n=47); and unicuspid aortic valve, 1% (n=3). Age and body surface area were similar in the 4 valve morphology groups. There was a significant trend, independent of age, toward larger body surface area-indexed ascending aortic diameters with increasing valve fusion. Ascending aortic diameters were (mean±SD) 16.9±3.3, 18.3±3.3, and 19.8±3.9 mm/m(2) (P<0.0001) for tricuspid aortic valve, partially fused aortic valve, and bicuspid aortic valve+unicuspid aortic valve, respectively. Partially fused aortic valve, bicuspid aortic valve, and unicuspid aortic valve were significantly associated with mild aortic regurgitation and elevated peak velocities across the aortic valve.

Conclusions: Aortic valve abnormalities in Turner syndrome occur with a spectrum of severity and are associated with aortic root dilation across age groups. Partial fusion of the aortic valve, traditionally regarded as an acquired valve problem, had an equal age distribution and was associated with an increased ascending aortic diameters.