Bicuspid aortic valve (BAV) disease is associated with an increased risk of aneurysms and dissections of the ascending aorta. The aim of this study was to evaluate the biomechanical properties of the ascending aorta in sporadic BAV patients which could potentially explain their aortic fragility.

A prospective monocentric study of BAV patients and their non-BAV relatives was conducted. Systolic and diastolic Valsava sinuses and tubular aortas were measured by transthoracic echocardiography, associated to the brachial blood pressure measurement with an oscillometric method. Distensibility and stiffness index calculations used aortic diameters variation over the cardiac cycle.

93 patients were tested for this study. 43 unoperated BAV patients (30 men, mean age 51±17 years with no significant valve dysfunction) were compared to 50 non-BAV relatives (26 male, mean age 42±18 years). BAV patients had a lower distensibility of the Valsalva sinus (2.28±1.74 vs. 3.72±3.04, p=0.005 and p=0.044 after adjustment for age and hypertension) and tubular aorta (2.30±1.74 vs. 3.34±2,74, p=0.055). Valsalva sinus stiffness index was higher in BAV patients (18,41±18,37 vs. 11,89±12,38, p=0,046) but this was not the case at the tubular aortic level (16,45±13,03 vs. 13,28±12,35, p=0,307). However Figure shows that tubular aortic stiffness index increases significantly with the aortic dilation (R²=0,334) in BAV patients which was not the case in non-BAV relatives (p=NS).

Ascending aorta of BAV demonstrated different biomechanics properties than non BAV relative with lower distensibility and increase of stiffness index at the level of Valsalva sinuses independently of age and blood pressure. We hope that aortic distensibility could be used to predict aortic dilation in BAV patient.

The author hereby declares no conflict of interest