Ascending aorta elasticity in children with isolated bicuspid aortic valve

Abstract

Background: Aortic dilation is common in children with bicuspid aortic valve (BAV) but aortic complications are infrequent. The aim of this study was to investigate elastic properties of the ascending aorta (AAo) and its relation to AAo size in children with isolated BAV without significant valve dysfunction.

Methods: 24 children with isolated BAV and 24 healthy controls with tricuspid aortic valve (TAV) matched by gender, age and body surface area (BSA) were studied. Aortic strain (AS), aortic distensibility (DIS) and aortic stiffness index (SI) were derived from M-mode echocardiography at the AAo together with cuff blood pressure recordings. BAV children with dilated AAo (z score ≥ 2) and non dilated (z score<2) were compared.

Results: BAV children had larger aortas than controls at the sinuses of Valsalva, sinotubular junction and AAo (p<0.05). AS was lower in BAV than in controls (10.15 ± 4.93 vs 16.93 ± 5.17 p=0.000), DIS was lower in BAV than in controls (8.51 ± 3.90 vs 14.37 ± 4.20 p=0.000) and SI was higher in BAV than in controls (7.19 ± 4.45 vs 4.05 ± 2.33 p=0.04). There were no significant differences in AS, DIS and SI between children with dilated and non-dilated AAo. AS, DIS and SI were not related to BSA, age or AAo size.

Conclusions: AAo elasticity assessed by transthoracic echocardiography is impaired in BAV children without significant valve dysfunction compared to TAV children. Impaired elasticity seems to be independent from aortic dilation. Measuring aortic elasticity may help to identify children at greater risk for complications as adults.

Keywords: Ascending aorta; Bicuspid aortic valve; Children; Congenital heart disease; Elasticity.