Bicuspid Aortic Valve: a not so Benign Congenital Heart Disease

Bicuspid aortic valve (BAV) is the most frequent congenital heart disease, with an incidence of approximately 1%. It can be silent and associated with normal valve function. However, a series of complications, even catastrophic, may occur with time: valve stenosis by dystrophic calcification, infective endocarditis, progressive dilatation of the ascending aorta with valve incompetence, aortic dissection, sudden death. The problem of BAV is not just the number of semilunar cusps. Severe noninflammatory degenerative changes (elastic fibers fragmentation, smooth muscle cells death, mucoid extracellular matrix accumulation) are observed in the aortic wall of BAV patients, with intrinsic weakness accounting for progressive aneurysmal dilatation of the ascending aorta, aortic valve incompetence and aortic dissection. The link between valve and aortic wall pathology finds most probably an explanation in the embryology of the arterial pole, since neurocrestal cells play a role in the development of both the ascending aorta, aortic arch and semilunar valves. The frequent association of adult aortic coarctation with BAV provides evidence for this hypothesis. BAV has a significant genetic component as to require screening of first-degree relatives, like outlined by AHA/ACC 2022 guidelines.