MISTRAL-C: Cerebral Protection in TAVR May Reduce New Lesions

In elderly patients undergoing transcatheter aortic valve replacement (TAVR), a filter-based embolic protection device was associated with a trend toward fewer new brain lesions, according to results of the randomized MISTRAL-C trial presented at TCT 2015. 

Embolic protection also resulted in smaller total lesion volume and reduced risk for neurocognitive deterioration, said Nicolas M. Van Mieghem, MD, PhD, of Erasmus Medical Center in Rotterdam, the Netherlands.

For the multicenter, double blind trial, Van Mieghem and colleagues randomly assigned 65 patients (mean age, 81 years; range, 78-85) to TAVR with (n = 32) or without (n = 33) embolic protection with the Sentinel Cerebral Protection System (Claret Medical).

Trial design called for patients to undergo 3-Tesla brain MRI, neurocognitive testing and clinical neurological exams at 1 day prior to TAVR and at 5 days after. Researchers determined that the number-needed-to-treat to demonstrate a reduction of new brain lesions from 80% to 40% with the embolic protection device was 54. However, only 37 total patients (embolic protection, n = 22; no embolic protection, n = 15) completed pre- and post-TAVR MRI.

Compared with those without embolic protection, those in the filter group demonstrated lower lesion volume both overall and in the anterior and posterior regions (Figure).

The median number of lesions was two in each treatment group (P = .274), but the interquartile range peaked at four in the embolic protection group vs. eight in the non-filter group.

Median single lesion volume also was smaller in the group in which protection was used (54 mm³ vs. 75 mm³; P = .313).

A higher percentage of patients in the embolic protection group had no new lesions both overall (27% vs. 13%; P = .312), in the anterior region (50% vs. 20%; P = .065) and in the posterior region (36% vs. 33%; P = .85). Additionally, neurocognitive assessments showed a higher percentage of patients without embolic protection experienced neurocognitive deterioration in the intention-to-treat population (n = 50; 27% vs. 4%; P = .017) and the as-treated population (n = 48; 30% vs. 4%; P = .011).

Mortality was lower in the embolic protection group at both 30 days (3% vs. 10%; P = .334) and 6 months (5% vs. 17%; P = .187) compared with the non-protected group. By day 30, there were no major strokes in the protected group vs two in the non-protected group (P = .144).

“Systematic brain MRI follow up in elderly patients undergoing [TAVR] is challenging,” Van Miegham acknowledged. He added that “adequately powered” trials are needed to confirm the MISTRAL-C findings.

Disclosures:

• Van Mieghem reports grant/research support from Claret Medical, Edwards Lifesciences, Medtronic and St. Jude; consultant/fees/honoraria from Abbott Vascular; and stock ownership/equity in Claret Medical.