Efficacy and safety of cerebral embolic protection systems during transcatheter aortic valve replacement: a review of current clinical findings

Cerebral Embolic Protection Devices: Current State of the Art

Transcatheter aortic valve replacement (TAVR) has become a first-line treatment for severe aortic stenosis with intermediate to high-risk population with its use increasingly expanding into younger and low-risk cohorts as well. Cerebrovascular events are one of the most serious consequential complications of TAVR, which increase morbidity and mortality. The most probable origin of such neurological events is embolic in nature and the majority occur in the acute phase after TAVR when embolic events are most frequent. Cerebral embolic protection devices have been designed to capture or deflect these emboli, reducing the risk of peri-procedural ischaemic events. They also carry the potential to diminish the burden of new silent ischemic lesions during TAVR. Our review explores different types of these device systems, their rationale, and the established clinical data.

Cerebral embolic protection and severity of stroke following transcatheter aortic valve replacement

BACKGROUND

The cerebral embolic protection (CEP) device captures embolic debris during transcatheter aortic valve replacement (TAVR). However, the impact of CEP on stroke severity following TAVR remains unclear. Therefore, we aimed to examine whether CEP was associated with reduced severity of stroke following TAVR.

METHODS

This was a retrospective cohort study of 2839 consecutive patients (mean age: 79.2 ± 9.5 years, females: 41.5%) who underwent transfemoral TAVR at our institution between 2013 and 2020. We categorized patients into Sentinel CEP users and nonusers. Neuroimaging data were reviewed and the final diagnosis of a cerebrovascular event was adjudicated by a neurologist blinded to the CEP use or nonuse. We compared the incidence and severity (assessed by the National Institutes of Health Stroke Scale [NIHSS]) of stroke through 72 h post-TAVR or discharge between the two groups using stabilized inverse probability of treatment weighting (IPTW) of propensity scores.

RESULTS

Of the eligible patients, 1802 (63.5%) received CEP during TAVR and 1037 (36.5%) did not. After adjustment for patient characteristics by stabilized IPTW, the rate of overall stroke was numerically lower in CEP users than in CEP nonusers, but the difference did not reach statistical significance (0.49% vs. 1.18%, p = 0.064). However, CEP users had significantly lower rates of moderate-or-severe stroke (NIHSS ≥ 6: 0.11% vs. 0.69%, p = 0.013) and severe stroke (NIHSS ≥ 15: 0% vs. 0.29%, p = 0.046). Stroke following CEP use (n = 8), compared with stroke following CEP nonuse (n = 15), tended to carry a lower NIHSS (median [IQR], 4.0 [2.0-7.0] vs. 7.0 [4.5-19.0], p = 0.087). Four (26.7%) out of 15 patients with stroke following CEP nonuse died within 30 days, with no death after stroke following CEP use.

CONCLUSIONS

CEP use may be associated with attenuated severity of stroke despite no significant difference in overall stroke incidence compared with CEP nonuse. This finding is considered hypothesis-generating and needs to be confirmed in large prospective studies.

Safety and performance of a novel cerebral embolic protection device for transcatheter aortic valve implantation: the PROTEMBO C Trial

BACKGROUND

Stroke remains a feared complication associated with transcatheter aortic valve implantation (TAVI). Embolic cerebral injury occurs in the majority of TAVI cases and can lead to cognitive dysfunction.

AIMS

The PROTEMBO C Trial evaluated the safety and performance of the ProtEmbo Cerebral Protection System in TAVI patients.

METHODS

Forty-one patients were enrolled in this single-arm study conducted at 8 European centres. The primary safety endpoint was the rate of VARC 2-defined major adverse cardiac and cerebrovascular events (MACCE) at 30 days; the primary performance endpoint was the composite rate of technical success versus performance goals (PG). Secondary endpoints included brain diffusion-weighted magnetic resonance imaging (DW-MRI), new lesion volume, and the rate of death or all strokes compared to historical data.

RESULTS

Thirty-seven of 41 enrolled patients underwent TAVI with the ProtEmbo device (intention-to-treat [ITT] population). Both primary endpoints were met. MACCE at 30 days was 8.1% (upper limit of the 95% confidence interval [CI]: 21.3% vs PG 25%; p=0.009), and technical success was 94.6% (lower limit of the 95% CI: 82.3% vs PG 75%; p=0.003). New DW-MRI lesion volumes with ProtEmbo were smaller than in historical data, and 87% of patients completing MRI follow-up had no single lesion >150 mm3. There was 1 stroke in a patient in whom the device was removed prematurely before TAVI completion.

CONCLUSIONS

The PROTEMBO C Trial met its primary safety and performance endpoints compared to prespecified historical PGs. Patients had smaller brain lesion volumes on DW-MRI compared to prior series and no larger single lesions. These results warrant further evaluation of the ProtEmbo in a larger randomised controlled trial (RCT).