Objective: This study was undertaken to examine the association between bicuspid aortic valve (BAV) and aortic dilatation in the community. The association between BAV and aortic dilatation has been reported predominantly in retrospective studies in patients mostly with valvular dysfunction or selected surgical patients from tertiary referral centers. An independent association of BAV and aortic dilatation in a community-based study has not been demonstrated.
Methods and results: In a geographically defined population of Olmsted County, Minnesota, residents with BAV (n=44, age 35+/-13 years) without hemodynamically significant obstruction or regurgitation and matched controls with normal tricuspid aortic valves were identified by transthoracic echocardiography. The two groups were compared with respect to measurements of the aorta. The BAV and control groups differed with respect to size of the aortic anulus (23.2+/-2.4 versus 21.6+/-2.4 mm; P=0.002), aortic sinus (33.5+/-4.6 versus 30.3+/-4.1 mm; P=0.0001), and proximal ascending aorta (33.3+/-6.5 versus 27.9+/-3.6 mm; P=0.0001). There was no difference in the size of the aortic arch (24.2+/-3.6 versus 25.3+/-3.4 mm; P=0.16). These differences were maintained when the groups were stratified by sex and blood pressure. The relationship between bicuspid aortic valve and aortic dilatation was maintained when adjusting for factors related to fluid mechanics and hemodynamics such as systolic blood pressure, diastolic blood pressure, left ventricular ejection time, and peak aortic valve velocity.
Conclusions: In a community-based study, BAV is associated with an alteration of aortic dimensions even in the absence of hemodynamically significant aortic valve stenosis or regurgitation.