Ascending Aortic Stiffness with Bicuspid Aortic Valve is Variable and Not Predicted by Conventional Parameters in Young Patients

Background and aim of the study: Bicuspid aortic valve (BAV)-related aortopathy is characterized by histological abnormalities that result in aortic wall stiffening and aortic dilation. The study aim was to determine the range of ascending aortic stiffness seen in a clinical cohort of patients with BAV, and to identify the association of aortic stiffness with standard clinical and imaging parameters.

Methods: Patients with BAV (n = 65) and normal subjects (n = 10) were studied using conventional phase-contrast magnetic resonance imaging through the ascending aorta. Local aortic stiffness was estimated by measuring pulse wave velocity (PWV) using the flow-area (QA) method. Correlations between PWV and other imaging and clinical variables were assessed, and multiple linear regression models were used to examine independent predictors of PWV.

mean PWV compared to normal subjects (6.53 ± 5.88 versus 3.51 ± 0.92 m/s; p <0.01) with a considerably wider range of values noted in the BAV group. Significant associations were found between PWV and age (r = 0.4, p <0.001) and history of hypertension (r = 0.36, p = 0.005) in the overall BAV cohort. The correlation between age and PWV was significantly strengthened above 40 years of age. In a subgroup of BAV patients aged <40 years (n = 37) there were no significant predictors of PWV identified by multiple linear regression models.

Conclusion: BAV patients demonstrated an increased average ascending aortic stiffness and a dramatically higher range of stiffness values compared to normal subjects. Increased stiffness is not predicted by standard clinical or imaging parameters in patients aged <40 years. Ascending aortic stiffness may be a unique marker of early aortic dysfunction in young BAV patients.

The Journal of Heart Valve Disease 2016;25:270-280