No abstract

In our study population, >50% of the patients admitted for surgery had a bicuspid valve. Aortic aneurysm was more common in BAV than in TAV patients. Aortic stenosis and aortic regurgitation were equally common in TAV and BAV with normal aortic dimensions, while aortic regurgitation was predominant in TAV with dilated aortas and aortic stenosis in BAV with dilated aortas. Dilatation of the aorta was similarly distributed regardless of BAV leaflet morphology. These findings support the idea of an intrinsic mechanisms underlying dilatation of the aorta in BAV patients.

Objective-Thoracic aortic aneurysm is a common complication in patients with bicuspid aortic valve (BAV).Alternatively

Individuals with a bicuspid aortic valve (BAV) are at significantly higher risk of developing aortic complications than individuals with tricuspid aortic valves (TAV) and defective signaling during the embryonic development and/or life time exposure to abnormal hemodynamic have been proposed as underlying factors. However, an explanation for the molecular mechanisms of aortopathy in BAV has not yet been provided. We combined proteomics, RNA analyses, immunohistochemistry, and electron microscopy to identify molecular differences in samples of non-dilated ascending aortas from BAV (N = 62) and TAV (N = 54) patients. Proteomic analysis was also performed for dilated aortas (N = 6 BAV and N = 5 TAV) to gain further insight into the aortopathy of BAV. Our results collectively showed the molecular signature of an endothelial/epithelial-mesenchymal (EndMT/EMT) transition-like process, associated with instability of intimal cell junctions and activation of RHOA pathway in the intima and media layers of ascending aorta in BAV patients. We propose that an improper regulation of EndMT/EMT during the spatiotemporally related embryogenesis of semilunar valves and ascending aorta in BAV individuals may result in aortic immaturity and instability prior to dilation. Exasperation of EndMT/EMT state in post embryonic life and/or exposure to non-physiological hemodynamic could lead to the aneurysm of ascending aorta in BAV individuals.