477Partial fusion of two aortic valve leaflets is related to alterations in ascending aorta flow: 4D flow CMR study

Abstract Introduction Bicuspid aortic valve (BAV) is the most common congenital valve defect. It consists in the fusion of two aortic valve leaflets, and it is associated with a high prevalence of proximal aorta dilation. Dilation is highly prevalent (around 30%) in BAV patient relatives with a tricuspid valve (TAV) identified by echocardiography. However, the presence of partial aortic valve leaflet fusion (also called mini-raphe or forme fruste BAV, see figure 1A) is easily missed by echocardiography. A recent study reported that 44% of patients from a small cohort of BAV patient relatives with aortic dilation followed by CT showed mini-raphe. Purpose We aimed to use 4D flow CMR to assess if the presence of mini-raphe is associated with aortic flow alterations, which may be concurs in the etiology of aortic dilation in BAV patient relatives. Methods Twenty BAV patients first-degree relatives with partial fusion (