Bicuspid aortic valve and coarctation: two villains part of a diffuse problem

Bicuspid aortic valve and coarctation of the aorta are congenital abnormalities often mistakenly considered as simple lesions that are discrete and localised. Evidence is mounting, however, that both their aetiology and pathophysiology are intimately related, and that they are part of a spectrum of a more generalised arteriopathy Bicuspid aortic valve is the most common congenital cardiovascular anomaly, occurring in 1–2% of the population. It has a male predominance and often occurs in multiple members of the same family, suggesting that it may have an autosomal dominant inheritance, perhaps with variable penetrance.1,2 Much of the data relating to its complications derive from necropsy studies since reliable diagnosis has only been possible for the last 15 years or so by two dimensional echocardiography. The most common complication is aortic stenosis and it is the most frequent cause of patients under 60 years of age requiring aortic valve replacement. Aortic stenosis appears to result from an active disease process reminiscent of atherosclerosis.3,4 It has features similar to the degenerative calcification that occurs on tricuspid aortic valves, but tends to occur at an earlier age, perhaps because of different mechanical or shear stresses on the bicuspid valve. Other complications include aortic regurgitation and infective endocarditis. The association of bicuspid aortic valve with aortic medial abnormalities has been known for decades and has been confirmed in many reports. Histologic examination of the ascending aorta frequently shows loss of smooth muscle cells and severe degeneration of the medial elastic fibres—so called “cystic medial necrosis”. The presence of a bicuspid valve increases the risk of dissection …