The role of flow stasis in transcatheter aortic valve leaflet thrombosis

Objective: With the recent expanded indication for transcatheter aortic valve replacement to low-risk surgical patients, thrombus formation in the neosinus is of particular interest due to concerns of reduced leaflet motion and long-term transcatheter heart valve durability. Although flow stasis likely plays a role, a direct connection between neosinus flow stasis and thrombus severity is yet to be established. Methods: Patients (n = 23) were selected to minimize potential confounding factors related to thrombus formation. Patient-specific 3-dimensional reconstructed in vitro models were created to replicate in vivo anatomy and valve deployment using the patient-specific cardiac output and idealized coronary flows. Dye was injected into each neosinus to quantify washout time as a measure of flow stasis. Results: Flow stasis (washout time) showed a significant, positive correlation with thrombus volume in the neosinus (rho = 0.621, P < .000l). Neither thrombus volume nor washout time was significantly different in the left, right, and noncoronary neosinuses (P >= .54). Conclusions: This is the first patient-specific study correlating flow stasis with thrombus volume in the neosinus post-transcatheter aortic valve replacement across multiple valve types and sizes. Neosinus-specific factors create hemodynamic and thrombotic variability within individual patients. Measurement of neosinus flow stasis may guide strategies to improve outcomes in transcatheter aortic valve replacement.

Automated summary

This study is the first patient-specific study that correlates flow stasis with thrombus volume in the neosinus post-transcatheter aortic valve replacement, covering multiple valve types and sizes. The results show a significant positive correlation between flow stasis and thrombus volume. Neosinus-specific factors lead to hemodynamic and thrombotic variability among individual patients. Measurement of neosinus flow stasis may guide strategies to improve outcomes in transcatheter aortic valve replacement.