Association between leaflet fusion pattern and thoracic aorta morphology in patients with bicuspid aortic valve

Purpose To determine if patients with certain bicuspid aortic valve (BAV) phenotypes are predisposed to particular morphological abnormalities of the thoracic aorta. Materials and Methods One hundred ninety-two patients with BAV who underwent magnetic resonance angiography between January 2007 and July 2010 were retrospectively identified. Aortic morphology was examined through measurements of aortic size index at nine levels along the thoracic aorta, three-dimensional volume of the ascending aorta, vessel asymmetry, and assessment of aortic root morphology. Results We found 140 patients (73%) with right and left coronary cusps (R-L) fusion, 46 patients (24%) with R-N fusion, and 6 patients (3%) with left and noncoronary cusps (L-N) fusion. Mean aortic volume in the proximal ascending aorta was significantly greater in R-L patients (0.93 versus 0.60 cm³/m²; P < 0.01). R-N patients possessed greater aortic size index at the distal ascending aorta and proximal aortic arch, and were also significantly more likely to have Type 2 patterns of aortic dilatation. Conclusion Our results suggest that BAV with R-L fusion is associated with increased dimensions of the aortic root, while BAV with R-N fusion is associated with increased dimensions of the distal ascending aorta and proximal arch. Our findings illustrate the morphological heterogeneity that exists among BAV phenotypes.