Embolic Protection Devices During TAVI: Current Evidence and Uncertainties

Transcatheter aortic valve implantation (TAVI) is now the principal therapeutic option in patients with severe aortic stenosis deemed inoperable or at high surgical risk. Implementing TAVI in a lower risk profile population could be limited by relatively high cerebrovascular event rates related to the procedure. Diffusion-weighted magnetic resonance imaging studies have demonstrated the ubiquitous presence of silent embolic cerebral infarcts after TAVI, with some data relating these lesions to subsequent cognitive decline. Embolic protection devices provide a mechanical barrier against debris embolizing to the brain during TAVI. We review the current evidence and ongoing uncertainties faced with the 3 currently available devices (Embrella, TriGuard and Claret) in TAVI. Studies evaluated neurological damage at 3 levels: clinical, subclinical, and cognitive. Feasibility and safety were analyzed for the 3 devices. In terms of efficacy, all studies were exploratory, but none demonstrated significant reductions in clinical event rates. The Embrella and Claret devices demonstrated significant reductions of the total cerebral lesion volume on diffusion-weighted magnetic resonance imaging. Studies evaluating the effects on cognition were also somewhat inconclusive. In conclusion, despite embolic protection devices demonstrating reductions in the total cerebral lesion volume on diffusion-weighted magnetic resonance imaging, the clinical efficacy in terms of preventing stroke/cognitive decline requires confirmation in larger studies.