Cerebral Embolic Protection Devices for Transcatheter Aortic Valve Replacement: Review of the Literature and Future Perspectives

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) has been a revolutionary therapy in the treatment of aortic valve stenosis. The risk of stroke associated with TAVR has decreased significantly since its introduction; however, it remains a devastating complication when it does occur.

RECENT FINDINGS

Many of the strokes associated with TAVR occur peri-procedurally and are thought to be due to embolic debris entering the cerebrovascular circulation. A number of different cerebral embolic protection devices (CEPD) have been developed and are in various stages of testing and use. The results from clinical trials evaluating the role for CEPD to reduce the risk of stroke have been mixed. As a result, their uptake has been very heterogeneous. This review provides a summary of the diverse CEPD devices available for use and outlines the clinical evidence available to date.

Cerebral Embolic Protection in Transcatheter Aortic Valve Implantation Using the Sentinel Cerebral Protection System: A Systematic Review and Meta-Analysis

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) plays a vital role in patients with symptomatic aortic stenosis. Despite the mortality benefit of TAVI, embolic stroke remains a feared complication. As a result, transcatheter cerebral embolic protection (TCEP) devices have been developed to reduce this risk. Given the ongoing debate of TCEP in TAVI, we performed a systematic review and meta-analysis of all randomized controlled trials to date to identify outcomes of periprocedural stroke using the Sentinel™ cerebral protection system (CPS).

METHODS

MEDLINE, Cochrane, and Scopus databases were utilized from inception until 12/2023. PRISMA criteria was utilized. Keywords included "cerebral embolic protection", "sentinel cerebral protection system", "transcatheter aortic valve implantation", and "transcatheter aortic valve replacement". Primary outcome was periprocedural stroke. Secondary outcomes included periprocedural disabling and non-disabling stroke, all-cause mortality, transient ischemic attack, delirium, acute kidney injury, vascular complications, bleeding, and pacemaker implantation. Risk ratios (RR) were measured via Mantel-Haenszel method with fixed analysis. Heterogeneity was assessed via chi-squared and Higgin's I2 test.

RESULTS

Four trials with 3528 patients were assessed. SAPIEN 3 was the most common bioprosthetic valve used. The average age was 79.4 years with 41.9% of the sample size being females. The most prevalent comorbidities were hypertension, diabetes mellitus, and coronary artery disease. There was no difference in periprocedural stroke in patients who underwent TAVI with the Sentinel™ CPS compared to no TCEP (RR 0.75, P = 0.12). Periprocedural disabling strokes were less likely in those who underwent TAVI with the Sentinel™ CPS compared to no TCEP (RR 0.41, P = 0.02) with a number needed to treat (NNT) of 123. All other outcomes did not reach statistical significance.

CONCLUSIONS

In our analysis, there was no difference between TAVI with the Sentinel™ CPS compared to TAVI without TCEP in regard to risk of periprocedural stroke; however, it was associated with a decreased risk of periprocedural disabling stroke.

Transradial carotid artery stenting using double layer micromesh stent and novel post-dilation balloon with integrated embolic protection

OBJECTIVES

The highest rate of embolization during carotid artery stenting occurs during post-dilation. We evaluated the ability of the Paladin system (Contego Medical, Raleigh, NC), a novel PTA balloon with an integrated 40-ɥm pore filter, to collect microemboli that may pass into the cerebral circulation when used during post-dilation.

METHODS

25 symptomatic patients underwent transradial CAS using the Paladin system in conjunction with the Roadsaver (Terumo Corporation, Tokyo, Japan) micromesh stent. No additional embolic protection was used. The Paladin filters were collected following the procedure and preserved in formalin for histological analysis. The contents were evaluated for particle count and size. Subjects were followed for 30 days and evaluated for major cardiac adverse events (death, stroke and MI). Secondary endpoints included procedure success, device success, access site complications according to EASY score classification, major vascular or ischemic complications at follow up and in-stent restenosis rate evaluated with duplex ultrasound.

RESULTS

Mean age of patients was 68,5 years. Type 2 aortic arch was present in 77 % of patients and type 1 and type 3 in 12 % and 11 % of patients respectively. Procedural and device success was obtained in all cases without complications. The 30-day MAE rate was 0 %. Twenty-three filters underwent histological analysis. Microscopic debris was present in 100 % of filters, and 75 % of particles were less than 100ɥm in size. The mean number of particles per filter was 3352 ± 1567 (IQR 4300-2343), and the mean number of particles between 40-100ɥm per filter was 2499 ± 1240 (IQR 3227-1575).

CONCLUSION

CAS through radial approach can be safely and effectively performed using the IEP technology Paladin device and double-layer micromesh Roadsaver stent. This strategy can simplify the procedure and decrease peri-procedural complications and procedural time.

An Updated Meta-Analysis on Cerebral Embolic Protection in Patients Undergoing Transcatheter Aortic Valve Intervention Stratified by Baseline Surgical Risk and Device Type

Background

Transcatheter aortic valve intervention (TAVI) can lead to the embolization of debris. Capturing the debris by cerebral embolic protection (CEP) devices may reduce the risk of stroke. New evidence has allowed us to examine the effects of CEP in patients undergoing TAVI. We aimed to assess the effects of CEP overall and stratified by the device used (SENTINEL or TriGuard) and the surgical risk of the patients.

Methods

We selected randomized controlled trials using electronic databases through September 17, 2022. We estimated random-effects risk ratios (RR) with (95% confidence interval) and calculated absolute risk differences at 30 days across baseline surgical risks derived from the TAVI trials for any stroke (disabling and nondisabling) and all-cause mortality.

Results

Among 6 trials (n = 3921), CEP vs. control did not reduce any stroke [RR: 0.95 (0.50-1.81)], disabling [RR: 0.75 (0.18-3.16)] or nondisabling [RR: 0.99 (0.65-1.49)] strokes, or all-cause mortality [RR: 1.23 (0.55-2.77)]. However, when analyzed by device, SENTINEL reduced disabling stroke [RR: 0.46 (0.22-0.95)], translating into 6 fewer per 1000 in high-risk, 3 fewer per 1000 in intermediate-risk, and 1 fewer per 1000 in low surgical-risk patients. CEP vs. control did not reduce the risk of any bleeding [RR: 1.03 (0.44-2.40)], major vascular complications [RR: 1.41 (0.57-3.48)], or acute kidney injury [RR: 1.36 (0.57-3.28)].

Conclusions

This updated meta-analysis showed that SENTINEL CEP might reduce disabling stroke in patients undergoing TAVI. Patients with high and intermediate surgical risks were most likely to derive benefits.

3D localization from 2D X-ray projection

PURPOSE

Most cardiology procedures are guided using X-ray (XR) fluoroscopy. However, the projective nature of the XR fluoroscopy does not allow for true depth perception as required for safe and efficient intervention guidance in structural heart diseases. For improving guidance, different methods have been proposed often being radiation-intensive, time-consuming, or expensive. We propose a simple 3D localization method based on a single monoplane XR projection using a co-registered centerline model.

METHODS

The method is based on 3D anatomic surface models and corresponding centerlines generated from preprocedural imaging. After initial co-registration, 2D working points identified in monoplane XR projections are localized in 3D by minimizing the angle between the projection lines of the centerline points and the working points. The accuracy and reliability of the located 3D positions were assessed in 3D using phantom data and in patient data projected to 2D obtained during placement of embolic protection system in interventional procedures.

RESULTS

With the proposed methods, 2D working points identified in monoplane XR could be successfully located in the 3D phantom and in the patient-specific 3D anatomy. Accuracy in the phantom (3D) resulted in 1.6 mm (± 0.8 mm) on average, and 2.7 mm (± 1.3 mm) on average in the patient data (2D).

CONCLUSION

The use of co-registered centerline models allows reliable and accurate 3D localization of devices from a single monoplane XR projection during placement of the embolic protection system in TAVR. The extension to different vascular interventions and combination with automatic methods for device detection and registration might be promising.

Neurologic Complications in Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has become the mainstay of treatment for severe symptomatic aortic stenosis. Although many TAVR complication rates including mortality and aortic regurgitation have decreased, stroke rates have remained stable for years. TAVR-related strokes are devastating to patients and their families, and very costly for health care systems. The predictors of stroke in TAVR are not yet well defined, although older age, female gender, carotid and peripheral arterial disease, bicuspid aortic valve anatomy, and atrial fibrillation are emerging as risk factors across studies.

Transcatheter Aortic Valve Replacement: Advances in Procedural Technology and Approaches

Transcatheter aortic valve replacement (TAVR) is now the dominant form of aortic valve replacement in the United States. Continued innovation has allowed the technique to be safe and democratized. New advances will increase the number of patients eligible to receive this therapy while increasing safety and efficiency. Herein, the authors review new TAVR technologies, approaches to valve deployment, and dedicated devices for cerebral embolic protection and vascular closure.

Cerebral embolic protection during transcatheter aortic valve replacement

BACKGROUND

It is controversial that cerebral embolic protection devices (CEPDs) reduce clinical stroke during transcatheter aortic valve replacement (TAVR). Herein, we investigated the impact of CEPDs on in-hospital clinical stroke using a nationally representative sample.

METHODS AND RESULTS

Using the National Inpatient Sample (NIS) database, 109,240 patients who underwent TAVR between 2017 and 2018 were included. They were categorized into 2 groups according to usage of CEPDs; the CEPD and non-CEPD groups. After propensity score matching, 3805 pairs were acquired. Our main outcome was in-hospital clinical stroke. Other outcomes were in-hospital mortality, acute kidney injury (AKI), AKI leading to hemodialysis, bleeding requiring transfusion, overall bleeding complications, infectious complications, length of stay, and total cost. In-hospital clinical stroke did not significantly differ between the 2 groups (0.7% versus 1.1%, p = 0.449). The CEPD group was associated with a significantly lower in-hospital mortality (0.5% versus 1.4%, p = 0.029) and reduced total cost ($49,047 ± 19,666 versus $50,051 ± 23,190, p < 0.001), compared with the non-CEPD group, whereas there were no significant differences in the other outcomes.

CONCLUSIONS

By using the NIS database with a large number of cases, TAVR with CEPDs was not associated with a lower incidence of in-hospital clinical stroke compared with no use of CEPDs after matching.

Patient eligibility for application of a two-filter cerebral embolic protection device during transcatheter aortic valve implantation: does one size fit all?

OBJECTIVES

This study sought to determine the percentage of patients potentially eligible for implantation of the Sentinel™ Cerebral Protection System (Sentinel-CPS) during transcatheter aortic valve implantation (TAVI) and to identify the reasons for treatment exclusion.

METHODS

We retrospectively performed an analysis of pre-TAVI multislice computed tomography (MSCT) aortograms and data review of all patients undergoing a TAVI procedure in 2017 (n = 317). MSCT evaluation included the assessment of aortic arch anatomy and the vascular dimensions of the brachiocephalic and left common carotid artery. Data analysis focused on comorbid conditions, precluding 6-Fr sheath radial access and filter deployment due to history of previous artery interventions.

RESULTS

MSCT and data analysis showed Sentinel-CPS compatibility in 61.5% of patients (n = 195). Sentinel-CPS would have been contraindicated in 38.5% (n = 122) due to one or more of the following: (i) measured diameters of the filter-landing zones <9 or >15 mm in the brachiocephalic artery and <6.5 or >10 mm in the left common carotid artery (n = 116; 88 with carotid dimensions too small); (ii) significant subclavian artery stenosis (n = 4) or an aberrant subclavian artery (n = 3) precluding Sentinel-CPS implantation and (iii) clinical characteristics including hypersensitivity to nickel-titanium (n = 1), radial artery occlusion (n = 1) or previous left common carotid artery interventions (n = 5).

CONCLUSIONS

MSCT and clinical data supported Sentinel-CPS compatibility in 61.5% of patients. The most common reason for treatment exclusion was inappropriate diameter within the target landing zone of the left carotid artery. Future device development should address this limitation.

Rate of peri-procedural stroke observed with cerebral embolic protection during transcatheter aortic valve replacement: a patient-level propensity-matched analysis

AIMS

The role of cerebral embolic protection (CEP) in transcatheter aortic valve replacement (TAVR) remains controversial. Randomized trials have not been powered to demonstrate a reduction in stroke rates. The aim of this patient level pooled analysis was to validate the impact of the dual-filter CEP device (Claret Medical Inc., CA, USA) on peri-procedural stroke in a large number of TAVR patients.

METHODS AND RESULTS

Patients from the SENTINEL US IDE trial were combined with the CLEAN-TAVI and SENTINEL-Ulm study in a patient level pooled analysis (N = 1306). Propensity score matching was performed to adjust for possible confounders. The primary endpoint was procedural stroke within 72 h post-TAVR according to Valve Academic Research Consortium-2 criteria. The secondary endpoint was the combination of all-cause mortality or all-stroke within 72 h after TAVR. In the propensity-matched population, 533 patients underwent TAVR without CEP and 533 patients underwent TAVR with CEP. TAVR patients without vs. with CEP were similar with respect to baseline characteristics, procedural approach, or valve type. In patients undergoing TAVR with dual-filter CEP, procedural all-stroke was significantly lower compared with unprotected procedures [1.88% vs. 5.44%, odds ratio 0.35, 95% confidence interval (CI) 0.17-0.72, relative risk reduction 65%, P = 0.0028]. In addition, all-cause mortality and all-stroke were significantly lower (2.06% vs. 6.00%, odds ratio 0.34, 95% CI 0.17-0.68, relative risk reduction 66%, P = 0.0013).

CONCLUSION

Our findings suggest that TAVR with the dual-filter CEP device is associated with a significant lower rate of peri-procedural stroke compared with unprotected procedures. However, randomized trials are still needed to clarify this issue.

Cerebral protection during transcatheter aortic valve implantation in an extreme high-risk patient

Stroke during transcatheter aortic valve replacement is one of the most feared complications. New technologies have been developed, attempting to prevent cerebral embolization of thrombotic and calcific debris. We report a 78-year-old patient (EuroSCORE log 45.6%, STS Stroke Score 5.1%) with calcific aortic stenosis at particular risk for cerebrovascular accidents. The patient underwent transapical transcatheter aortic valve replacement using the dual filter-based Claret Sentinel™ Device for cerebral protection. Claret Sentinel Device use was associated with capture of macroscopic debris. Postoperatively, no neurological deficits could be detected by the National Institutes of Health Stroke Scale and modified Rankin scale.