Balancing the Risks of Thrombosis and Bleeding Following Transcatheter Aortic Valve Implantation: Current State-of-Evidence

While transcatheter aortic valve implantation (TAVI) has rapidly evolved as an acceptable alternative to conventional surgical aortic valve replacement in elderly, high-risk surgical candidates with critical aortic stenosis, thrombotic and bleeding complications remain relatively frequent and potentially life-threatening. Thrombotic events during and following TAVI relate to the dynamic interplay between the systemic burden of atherosclerotic disease, atrial arrhythmias, device and native aortic valve interactions, as well as platelet and coagulation cascade activation. Bleeding in the acute setting relates primarily to access site vascular complications, but also appears related to pre-existing renal impairment and anemia. Current pre-, peri- and post-procedural anti-thrombotic regimens are empirical, based on expert consensus following extrapolation from the wealth of experience gleaned following percutaneous coronary intervention. However the complexities of the TAVI procedure, the high-risk clinical substrate and competing effects of anti-thrombotic regimens and bleeding risk are yet to be prospectively assessed in randomized clinical trials for defining evidence-based anti-thrombotic strategies.