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

ABSTRACT

BACKGROUND: 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. RESULTS: BAV patients demonstrated a significantly higher 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. CONCLUSIONS: 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.