Transcatheter aortic valve deployment influences neo‐sinus thrombosis risk: An in vitro flow study

OBJECTIVES: We investigated the impact of (transcatheter heart valve) THV expansion at the level of the native annulus and implant depth on valve performance and neo-sinus flow stasis. BACKGROUND: Flow stasis in the neo-sinus is one of the identified risk factors of THV thrombosis. METHODS: A 29 mm CoreValve and 26 mm SAPIEN 3 were deployed under different expansions (CoreValve, SAPIEN 3) and implant depths (CoreValve) within a patient-derived aortic root in a pulse duplicator. Fluorescent dye was injected during diastole into the neo-sinus and imaged over 20 cardiac cycles. Washout times were computed as a measure of flow stasis for each deployment. RESULTS: The 10% CoreValve under-expansion improved neo-sinus washout over full expansion by 8% (p < .001), and higher CoreValve implant depth improved neo-sinus washout (p < .001). The 10% SAPIEN 3 under-expansion improved neo-sinus washout by 23% (p < .001). Under-expansion of both valve types caused higher pressure gradients and smaller effective orifice areas than full expansion. CONCLUSIONS: Neo-sinus flow stasis is influenced by THV expansion and implant depth (CoreValve). The 10% valve under-deployment (oversizing) may facilitate reduced flow stasis in the neo-sinus with minimal increase in pressure gradients. This strategy may be helpful for patient anatomies, which are in-between transcatheter valve sizes.