Objectives: This study aimed to determine the prevalence of dilation and abnormal elastic properties of aortic root in first-degree relatives (FDRs) of bicuspid aortic valve (BAV) patients.
Background: Evidence indicates that BAV is a genetic disorder. Although FDRs of affected individuals have an increased prevalence of BAV, their risk of aortic root abnormalities is unknown.
Methods: We studied dimensions as well as the elastic properties of the ascending aorta in 48 FDRs with morphologically normal tricuspid aortic valves, 54 BAV patients, and 45 control subjects using 2-dimensional echocardiography.
Results: The prevalence of aortic root dilation was 32% in FDRs and 53% in BAV patients, whereas all control subjects showed normal aortic dimensions (p < 0.001). The FDRs and BAVs had significantly lower aortic distensibility (1.7 +/- 1.4 x 10(-3) mm Hg and 1.4 +/- 2.0 x 10(-3) mm Hg vs. 2.5 +/- 1.6 x 10(-3) mm Hg, p < 0.001) and greater aortic stiffness index (26.7 +/- 25.8 and 55.9 +/- 76.8 vs. 18.7 +/- 40.1, p = 0.001) compared with control subjects. This difference remained significant in subjects without aortic root dilation or hypertension (p = 0.002 and p = 0.004, respectively).
Conclusions: The aortic root is functionally abnormal and dilation is common (32%) in first-degree relatives of patients with BAV. Screening of FDRs by transthoracic 2-dimensional echocardiography should be considered for detection of aortic valve malformation and dilated ascending aorta.