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.