Embolic Protection During TAVR Reduces Volume of Cerebral Lesions, but Clinical Benefit Not Evident: Meta-analysis

PARIS, France—The use of embolic protection devices when performing transcatheter aortic valve replacement may be associated with a smaller volume of silent ischemic lesions, according to results of a new meta-analysis.

Investigators caution, however, that the clinical significance of this reduction in lesion volume is far from understood, noting that embolic protection during TAVR was not associated with a reduction in clinically evident stroke or mortality.

“There is a lack of correlation between silent ischemic lesions assessed by diffusion-weighted MRI compared with outcomes that are clinically apparent,” lead author Rodrigo Bagur, MD, PhD (Western University, London, Canada), told TCTMD. For example, previous studies have suggested that as many as two-thirds of TAVR-treated patients might experience silent cerebral lesions, but the most recent registry data suggest the stroke rate is less than 2%, which is down significantly from what had been observed in the earlier landmark trials, said Bagur.

In the meta-analysis, which was presented last week at EuroPCR and recently published in Stroke, investigators included 16 studies with 1,170 patients, of whom 865 were treated with embolic protection. The types of devices used in the trials varied, with several involving the Embrella embolic deflector (Edwards Lifesciences), TriGuard (Keystone Heart), and Sentinel and Montage (Claret Medical). A fourth device originally designed for open heart procedures, the Embol-X system (Edwards Lifesciences), was also tested and included in the meta-analysis.      

“The rationale for this meta-analysis was to determine if there was a real benefit in terms of patient-important outcomes using embolic protection devices during TAVR procedures,” said Bagur. “The reason we say this is because most recent registries have shown a dramatic decrease in the rates of clinically apparent cerebrovascular accidents following TAVR.” 

Overall, the analysis showed the use of embolic protection during TAVR was not associated with a reduction in the risk of clinically evident stroke or 30-day mortality. Additionally, there was no significant benefit in terms of reducing the number of new or total cerebral lesions as assessed by diffusion-weighted MRI.

Embolic protection was associated with significantly smaller ischemic volume per lesion and smaller total volume of lesions, however. Importantly, in a subgroup analysis, treatment with self-expanding TAVR systems was associated with a greater reduction in the number and total volume of new lesions per patient when compared with the latest-generation balloon-expandable Sapien 3 valve (Edwards Lifesciences).

To TCTMD, Bagur said embolic protection devices are a “sexy” add-on option during TAVR but the long-term benefits of reducing lesion volume on diffusion-weighted MRI are not yet proven. As the procedure moves into intermediate- and lower-risk patients, it’s important to continue to follow these patients to determine if these clinically silent cerebral lesions “have a significant impact on cognitive decline,” he said. “We just don’t know yet.”

Bagur noted that the SENTINEL trial included a primary safety endpoint focused on clinical events (which did not differ significantly between the filter-device and control arms) and an efficacy endpoint focused on imaging, but prior studies were based on MRI endpoints only. The comparison of studies with clinical and imaging endpoints as well as the inclusion of different protection devices, most of which were tested with different TAVR devices, are just some of the limitations of the analysis, he said.

Most of the trials included in the meta-analysis did not include a systematic evaluation by a neurologist, he added.