Elastic Properties of the Descending Aorta in Patients with a Bicuspid or Tricuspid Aortic Valve and Aortic Valvular Disease

Abstract

The aim of this study was to explore possible differences in aortic strain, distensibility, and stiffness in the descending thoracic aorta between patients with bicuspid aortic valves (BAVs) and those with tricuspid aortic valves (TAVs) in relation to type of aortic valve disease and known cardiovascular risk factors. Transesophageal echocardiography was used to examine 288 patients (mean age, 64 ± 13 years) in the operating room before surgery. The transesophageal echocardiographic images were analyzed offline using Velocity Vector Imaging software. One hundred forty patients had isolated severe aortic stenosis (AS) (89 of those with BAVs, 51 of those with TAVs), and 52 patients had isolated severe aortic regurgitation (AR) (24 of those with BAVs, 28 of those with TAVs). In patients with AS, stiffness in the descending aorta was 10 (range, 7.3-16) in those with BAVs and 13 (range, 11-18) in those with TAVs (P < .001). Distensibility was 19 kPa(-1) 10(-3) (range, 13-27 kPa(-1) 10(-3)) in patients with BAVs and 15 kPa(-1) 10(-3) (range, 11-19 kPa(-1) 10(-3)) in those with TAVs (P < .01). In patients with AR, stiffness was 6.9 (range, 5.5-7.8) in those with BAVs and 8.0 (range, 6.6-11) in those with TAVs (P < .05). After correction for age, dimension of the ascending aorta, cholesterol, and stroke volume in a multivariate regression model, BAV was associated with lower strain and distensibility of the descending aorta in the AR group and higher distensibility in the AS group, whereas stiffness was no longer related to aortic valve morphology in either of the two groups. The presence of BAVs in patients with severe AR is associated with lower strain and distensibility, suggesting that impairment of the elastic aortic properties may extend to the descending aorta. In patients with AS, BAVs correlate weakly with higher distensibility.