From unicuspid to quadricuspid: Influence of aortic valve morphology on aortic three-dimensional hemodynamics

Purpose: To assess the impact of aortic valve morphology on aortic hemodynamics between normal tricuspid and congenitally anomalous aortic valves ranging from unicuspid to quadricuspid morphology.

Materials and Methods: Aortic three-dimensional (3D) blood flow was evaluated by 4D flow MRI in 14 healthy volunteers with normal trileaflet valves and 14 patients with unicuspid (n = 3), bicuspid (n = 9, 3 "true" bicuspid, 3 right-left (RL), 3 right-noncoronary (RN) leaflet fusion, and quadricuspid aortic valves (n = 2). Data analysis included the co-registered visualization of aortic valve morphology with systolic 3D blood flow. The influence of valve morphology on aortic hemodynamics was quantified by valve flow angle.

Results: All RL-bicuspid aortic valve (BAV) were associated with flow jets directed toward the right anterior aortic wall while RN-fusion and unicuspid valves resulted in flow jet patterns toward the right-posterior or posterior wall. Flow angles were clearly influenced by valve morphology (47° ±10, 28° ±2, 29° ±18, 18° ±12, 15° ±2 for unicuspid, true BAV, RN-BAV, RL-BAV, quadricuspid valves) and increased compared with controls (7.2° ± 1.1, P=0.001).

Conclusion: Altered 3D aortic hemodynamics are impacted by the morphology of congenitally malformed aortic valves.