Cerebral Embolic Protection During Transcatheter Aortic Valve Replacement: A Systematic Review of Effects on Diffusion-Weighted MRI Lesions, Clinical Stroke, and Early Cognition

Cerebral embolic protection devices (CEPDs) are used during transcatheter aortic valve replacement (TAVR) to intercept or deflect embolic material generated during the procedure, with the goal of reducing neurologic injury. We systematically compared CEPD to no CEPD for periprocedural clinical stroke (≤72 hours or at discharge; disabling stroke when reported), diffusion-weighted magnetic resonance imaging (DW-MRI) surrogate lesions, and early cognitive change. We prioritized the ≤72-hour/at-discharge window because CEPDs act during the index procedure, and this time frame aligns with commonly used periprocedural stroke definitions, whereas later events may reflect additional post-discharge factors and were inconsistently reported across studies. PubMed and ScienceDirect were searched from inception; randomized trials and comparative cohort studies were eligible. The risk of bias was assessed using the revised Cochrane Risk of Bias tool (RoB 2) and Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I); the certainty of evidence was graded with Grading of Recommendations, Assessment, Development, and Evaluation (GRADE); and the protocol was prospectively registered (PROSPERO CRD420251120071). Given substantial clinical and methodological heterogeneity, findings were synthesized narratively. Nine studies met the inclusion criteria (seven randomized trials and two cohorts). Mechanistic trials generally reported fewer and/or smaller new DW-MRI lesions with CEPD use, particularly when supra-aortic vessel coverage was more complete. In the largest randomized trial to date, early any-stroke rates were similar between cerebral embolic protection and control, while disabling stroke showed a possible reduction with protection. Other Sentinel studies confirmed frequent debris capture and suggested reductions in lesion burden but did not demonstrate consistent early clinical benefit. Early cognition was assessed infrequently and with varied tools and time points; MISTRAL-C suggested less very-early decline associated with smaller lesion burden, whereas larger studies found no clear mean advantage. Because cognitive outcomes influence rehabilitation, functional recovery, and independence after TAVR, standardized cognitive assessment remains a key evidence gap. Overall, CEPD use appears to improve DW-MRI surrogate measures but has not shown a reliable reduction in overall periprocedural stroke; any potential benefit for disabling stroke remains uncertain. Certainty of evidence was moderate for any stroke, low to moderate for DW-MRI outcomes, and low for early cognition. These findings support selective rather than routine CEPD use and emphasize the need for coverage-verified trials with standardized neurologic and cognitive follow-up.