Incidence and predictors of debris embolizing to the brain during transcatheter aortic valve implantation.

OBJECTIVES: The aim of this study was to identify variables associated with tissue fragment embolization during transcatheter aortic valve replacement (TAVR). BACKGROUND: Brain magnetic resonance imaging and transcranial Doppler studies have revealed that cerebrovascular embolization occurs frequently during TAVR. Embolized material may be r thrombotic, tissue derived, or catheter (foreign material) fragments. METHODS: A total of 81 patients underwent TAVR with a dual filter-based embolic protection device (Montage Dual Filter System, Claret Medical, Inc., Santa Rosa, California) deployed in the brachiocephalic trunk and left common carotid artery. Both balloon-expandable and self-expanding transcatheter heart valves (THVs) were used. Filters were retrieved after TAVR and sent for histopathological analysis. RESULTS: Overall, debris was captured in 86% of patients. Captured material varied in size from 0.1 to 9.0 mm. Thrombotic material was found in 74% of patients and tissue-derived debris in 63%. Tissue fragments were found more often with balloon-expandable THVs (79% vs. 56%; p = 0.05). The embolized tissue originated from the native aortic valve leaflets, aortic wall, or left ventricular myocardium. On multivariable logistic regression analysis, balloon-expandable THVs (odds ratio: 7.315; 95% confidence interval: 1.398 to 38.289; p = 0.018) and cover index (odds ratio: 1.141; 95% confidence interval: 1.014 to 1.283; p = 0.028) were independent predictors of tissue embolization. CONCLUSIONS: Debris is captured with filter-based embolic protection in the vast majority of patients undergoing TAVR. Tissue-derived material is found in 63% of cases and is more frequent with the use of balloon-expandable systems and more oversizing.