Silent cerebral injury after transcatheter aortic valve implantation and the preventive role of embolic protection devices: A systematic review and meta-analysis

Background: The aims of this study were: 1) to evaluate silent cerebral injury detected by cerebral diffusion weighted magnetic resonance imaging (DW-MRI) after transcatheter aortic valve implantation (TAVI); and 2) to assess the efficacy of embolic protection devices (EPDs) on DW-MRI endpoints. Methods: We included in a pooled analysis 25 prospective studies reporting post-procedural cerebral DW-MRI data after TAVI (n = 1225). Among these studies, we included in a meta-analysis 6 studies investigating TAVI performed with versus without EPDs (n = 384). Primary endpoints were the number of new lesions per patient and the total lesion volume, while secondary endpoints were the number of patients with new lesions and the single lesion volume. Results: The main pooled DW-MRI outcomes were: patients with new ischemic lesions, 77.5% (95% confidence interval = 71.7-83.3%); total lesion volume, 437.5 mm(3) (286.7-588.3 mm(3)); single lesion volume, 78.1 mm(3) (56.7-99.5 mm(3)); and number of new lesions per patient, 4.2 (3.4-5.0). The use of EPDs was associated with a significant reduction in total lesion volume (mean difference [95% confidence interval] = -111.1 mm(3) [-203.6 to -18.6 mm(3)]; p = 0.02) and single lesion volume (-12.1 mm(3) [-18.3 to -6.0 mm(3)]; p = 0.0001) after TAVI. Conclusions: Silent cerebral injury occurs in the majority of patients undergoing TAVI and DW-MRI allows a precise characterization of new ischemic brain lesions. EPDs reduce the total and single volume of such lesions detected after the procedure, although the number of new lesions per patient and the number of patients with new lesions are not significantly reduced by such devices. (C) 2016 Elsevier Ireland Ltd. All rights reserved.