Flow Dynamic Factors Correlated With Device-Related Thrombosis After Left Atrial Appendage Occlusion

Background: Device-related thrombosis (DRT) occurs in up to 4% of patients undergoing left atrial appendage occlusion (LAAO) and is associated with substantial morbidity and mortality. However, its pathophysiology, predictors, and optimal management remain unclear.

Objectives: This study aims to assess flow dynamic factors correlating to DRT.

Methods: A multicenter registry of patients who underwent LAAO and had pre- and post-computed tomography imaging was used. Patient-specific 3-dimensional digital models of the left atrium were created, and finite element simulations were performed to implant an LAAO device into each model in a position that matched the clinical deployment. Computational fluid dynamic simulations were performed to quantify the following flow dynamic parameters: time averaged wall shear stress, oscillatory shear index, and endothelial cell activation potential.

Results: A total of 38 patients (19 with DRT and 19 without DRT) were included. Left atrium volumes and mitral valve areas were larger in the DRT cohort compared with controls. Patients with DRT had a significantly lower time averaged wall shear stress (1.76 ± 1.24 Pa vs 2.90 ± 2.70 Pa), a higher oscillatory shear index (0.19 ± 0.11 vs 0.17 ± 0.11), and a higher endothelial cell activation potential (0.23 ± 0.58 Pa^-1 vs 0.17 ± 0.30 Pa^-1) than the controls (P < 0.001 for all). Thrombus locations identified from in-vivo images correlated well with the flow dynamic parameters tested.

Conclusions: Flow dynamic parameters may be able to predict the risk of DRT after LAAO. Further investigation with a larger patient cohort and long-term follow-up is needed to assess the role of computational fluid dynamics in the risk stratification of patients considered for LAAO.