The difficult balance between thrombosis and bleeding after transcatheter aortic valve replacement: A translational review

Transcatheter aortic valve replacement (TAVR) has emerged as the treatment of choice for patients with severe aortic stenosis deemed at high or intermediate risk for cardiac surgery. In light of the latest literature advances, TAVR will undoubtedly concern a growing number of patients because of the progressive extension of its indications. Whereas significant efforts have been made to reduce the burden of periprocedural complications, TAVR still exposes patients to a sizeable number of adverse outcomes, including thrombotic and bleeding events. Although contradictory, these two phenomena are closely related to pathophysiological processes inherent to flow disturbances induced by aortic stenosis itself, but also to a complex interaction between bioprosthetic valves and native tissues in frail patients clustering various co-morbidities. Reinforcing this paradigm, multiple TAVR studies have emphasized the view that both thrombosis and bleeding events have a deleterious effect on patient outcomes. Therefore, we sought to perform a comprehensive translational review of the current literature addressing the pathophysiological mechanisms leading to thrombosis and bleeding after TAVR, and underline innovative strategies aimed at reducing these complications.