Implications of Bicuspid Aortic Valves for Transcatheter Aortic Valve Implantation

Abstract

Bicuspid aortic valve (BAV) occurs in 0.5% to 2% of the general population, with strong male predilection.1 Valvular complications include aortic stenosis, aortic regurgitation (AR), and infective endocarditis. Vascular complications comprise aortic dilatation, aneurysm formation, and aortic dissection. Coarctation of the aorta and left coronary artery dominance are also associated with BAV.1 BAV consists of 2 cusps, usually of unequal size.2 The larger cusp may contain 1 or 2 raphes—fibrous ridges extending from the malformed commissure to the free edge of the 2 conjoint cusps.2 An anatomic classification distinguishes BAV types principally by the number of raphes (Figure).2 Because a raphe can be missed on echocardiography, Schaefer et al3 proposed 3 types based instead on the pattern of leaflet fusion. Clinical presentation of BAV is variable. Some patients present with severe disease in infancy, whereas others present with asymptomatic disease in old age.1 In a recent series of 642 asymptomatic adults with BAV referred to a tertiary center, 25% had a primary cardiac event at mean follow-up of 9 years.4 Aortic valve or ascending aorta intervention comprised most (22%) events.4 In another series of 212 asymptomatic adults with BAV recruited from the community, primary cardiac outcomes occurred in 42% at 20-year follow-up.5 Overall survival rates were similar to the general population.5 Figure. Anatomic classification of bicuspid aortic valves (BAV) based on a study of 304 surgical specimens.2 Prominent black lines denote the raphe (s). Type 0=no raphe, type 1=1 raphe, and type 2=2 raphes. Each type is subcategorized according to the spatial position of the cusps (type 0) or raphes (types 1 and 2). Percentages represent the approximate prevalence of each BAV type observed in the Sievers study.2 ap indicates anterior-posterior; L, left coronary sinus; lat, lateral; …