Transcatheter aortic valve thrombosis: a review of potential mechanisms

Abstract

Transcatheter aortic valve (TAV) thrombosis has been recognized as a significant problem that sometimes occurs as early as within 30 days after valve implantation, leading to increased concerns of stroke and long-term valve durability. In this article, a critical summary of the relevant literature on identifying potential mechanisms of TAV thrombosis from the perspective of the well-known Virchow's triad, which comprises blood flow, foreign materials and blood biochemistry, is presented. Blood flow mechanisms have been the primary focus thus far, with a general consensus on the flow mechanisms with respect to haemodynamic conditions, the influence of TAV placement and expansion and the influence of coronary flow. Less attention has been paid to the influence of blood biochemistry and foreign materials (and related endothelial damage), with little consensus among studies with regards to platelet and/or microparticle levels post-TAV implantation. Finally, we discuss the future outlook for research with unanswered scientific questions.

Repeated acute coronary syndrome caused by a mind-bending mural thrombus in ascending aorta: a case report and review of the literature

“…Although the pathophysiological mechanism of an ascending aortic mural thrombosis has not been fully explored, the principle of Virchow’s triad for thrombogenesis remains closely related. Virchow’s triad describes the three factors related to thrombosis: hemodynamics (fluid stasis), endothelial injury (associated with foreign materials), and hypercoagulability (abnormal blood chemistry) [ 13 ]. The high-flow environment of the ascending aorta, characterized by the large blood flow, the high blood pressure and high shear stress, theoretically serves as a protective mechanism against stasis and thrombosis, and contributes to the scarcity of mural thrombi at the proximal ascending aorta.…”

Computational Methods for Fluid-Structure Interaction Simulation of Heart Valves in Patient-Specific Left Heart Anatomies

“…Vortex ring formation induced by shear-layer roll-up [16][17][18] has been shown to increase viscous dissipation [19,20] and could also lead to high shear stresses [21], increasing the risk for thrombus formation. Regions of flow stagnation inside the sinuses could also lead to thrombosis [22] or leaflet calcification [23] due to the associated low-shear-stress environment. Numerical methods for heart valves [24] must be able to account for the large deformation of valvular leaflets as well as the aforementioned complex flow characteristics.…”

“…Bioprosthetic valves are the most advanced valvular prostheses [35] to date. The structural components of those prostheses consist of thin leaflets and flexible stents, while the structural mechanics [47] of these valves are well studied, their long-term interaction with blood flows [22] remains a concern due to the risk of thrombogenicity [48]. In this review, we focus on the interaction of leaflets and blood flow dynamics.…”

Analysis of fibrocalcific aortic valve stenosis: computational pre-and-post TAVR haemodynamics behaviours

“…Also, post-processing implementation options were evaluated including single and repeated passages stress accumulation (SA) with time averaging [ 33 ]. Studies also focused on the blood biochemistry and blood contact with foreign surfaces, with regards to micro-particle levels post-implantation [ 34 ]. Flow stasis showed a strong correlation with the thrombus volume in the neosinus [ 35 ].…”