Imaging and functional testing to assess clinical and subclinical neurological events after transcatheter or surgical aortic valve replacement: a comprehensive review

Neurological events after transcatheter (TAVR) or surgical aortic valve replacement (SAVR) are potentially devastating and associated with a poor prognosis. With technological improvements and increased operator experience, their incidence is markedly declining, justifying the need for surrogate endpoints to be used in future comparative trials. Moreover, imaging studies after TAVR and SAVR suggest that neurological events are mainly embolic in nature; however, there is significant discrepancy between imaging findings and clinically overt symptoms, raising the possibility of more subtle subclinical cognitive decline. Different modalities have been used to assess both overt and subclinical neurological events after SAVR and TAVR. The purpose of this report is to systematically review and describe currently used imaging, functional, and neurocognitive testing modalities and to better understand how they could be integrated in future prospective studies.