First-in-Man Study Evaluating the Emblok Embolic Protection System During Transcatheter Aortic Valve Replacement

Cerebral embolic protection for stroke prevention during transcatheter aortic valve replacement

INTRODUCTION

Cerebral Embolic Protection Device (CEPD) captures emboli during Transcatheter Aortic Valve Replacement (TAVR). With recently published pivotal trials and multiple cohort studies reporting new data, there is a need to re-calibrate available statistical evidence.

METHODS

A systematic literature search was conducted across databases from inception till February 2023. Dichotomous outcomes were pooled using Odds Ratio (OR), while continuous outcomes were pooled using Standardized Mean Difference (SMD) along with 95% corresponding intervals (95% CIs).

RESULTS

Data was included from 17 studies (7 RCTs, 10 cohorts, n = 155,829). Use of CEPD was associated with significantly reduced odds of stroke (OR = 0.60, 95% CI = 0.43-0.85, p = 0.003). There was no significant difference in disabling stroke (p = 0.25), non-disabling stroke (p = 0.72), and 30-day mortality (p = 0.10) between the two groups. There were no significant differences between the two groups for Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) findings, acute kidney injury, risk of pacemaker implantation life-threatening bleed, major bleed, minor bleed, worsening National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and vascular complications (p > 0.05).

CONCLUSIONS

The use of CEPD during TAVR reduced the incidence of all-stroke (p = 0.003); however, there were no significant differences in any of the other pooled outcomes (p > 0.05).

REGISTRATION

The protocol of this meta-analysis was registered with the Open Science framework [https://doi.org/10.17605/OSF.IO/7W564] before data acquisition was started.

Clinical impact of cerebral protection during transcatheter aortic valve implantation

BACKGROUND

Embolization of debris can complicate transcatheter aortic valve implantation (TAVI) causing stroke. Cerebral embolism protection (CEP) devices can divert or trap debris.

PURPOSE

To evaluate the efficacy of CEP during TAVI vs the standard procedure.

DATA SOURCES

PubMed, SCOPUS and DOAJ 1/01/2014-04/12/2023.

STUDY SELECTION

Randomized and observational studies comparing CEP versus standard TAVI, according to PRISMA.

PRIMARY OUTCOME

stroke.

SECONDARY OUTCOMES

death, bleeding, vascular access complications, acute kidney injury and infarct area.

DATA EXTRACTION

Two investigators independently assessed study quality and extracted data.

DATA SYNTHESIS

Twenty-six articles were included (540.247 patients). The primary endpoint was significantly lower (RR = 0.800 95%CI:0.682-0.940; p = 0.007) with CEP. Similarly, death rates were significantly lower with CEP (RR = 0.610 95%CI:0.482-0.771; p < 0.001). No difference was found for bleeding (RR = 1.053 95%CI:0.793-1.398; p = 0.721), vascular complications (RR = 0.937 95%CI:0.820-1.070; p = 0.334) or AKI (RR = 0.982 95%CI:0.754-1.279; p = 0.891).

CONCLUSIONS

Use of CEP during TAVI is associated with improved outcomes. Future studies will identify patients who benefit most from CEP.

A Novel System for Transcatheter Aortic Valve Implantation: First-in-Man Study

Transcatheter aortic valve implantation (TAVI) has become a therapeutic treatment for severe symptomatic patients with aortic stenosis. This study aimed to test a novel transcatheter aortic self-expandable bioprosthesis-the ScienCrown system (Lepu Medtech Inc., Beijing, China)-and evaluate the safety of the new device during TAVI. ScienCrown aortic valve implantation was performed on 10 patients. Clinical assessment was performed at baseline, post procedure, and after 1 year. Clinical outcomes and adverse events were assessed according to Valvular Academic Research Consortium-3 criteria. The mean age was 75.30 ± 4.78 years with a mean Society of Thoracic Surgeons score of 4.64 ± 3.23%. Device success was achieved in all patients (80% transfemoral, 20% transapical). After 1 year, there were no deaths, disabling strokes, myocardial infarctions, conversions to surgery, or major procedure-related complications. New pacemaker implantation was required in one patient (10%). ScienCrown implantation resulted in a reduction in mean valve gradient (63.00 ± 18.84 to 9.67 ± 4.97 mm Hg, p <0.001) and an increase in effective orifice area (0.57 ± 0.20 to 2.57 ± 0.59 cm2, p <0.001) at 1 year. Paravalvular leak was absent in 9 patients (90%), and there was a trace in one patient (10%). All patients were in New York Heart Association class I to II at a mean follow-up of 1 year. The experience showed that ScienCrown transcatheter aortic valve system was safely and successfully implanted for treatment of severe symptomatic aortic stenosis. The newer-generation device affords a stable implantation while providing optimal hemodynamic performance.

Transcatheter aortic valve replacement: Past, present, and future

Transcatheter aortic valve replacement (TAVR) has emerged as a ground-breaking, minimally invasive alternative to traditional open-heart surgery, primarily designed for elderly patients initially considered unsuitable for surgical intervention due to severe aortic stenosis. As a result of successful large-scale trials, TAVR is now being routinely applied to a broader spectrum of patients. In deciding between TAVR and surgical aortic valve replacement, clinicians evaluate various factors, including patient suitability and anatomy through preprocedural imaging, which guides prosthetic valve sizing and access site selection. Patient surgical risk is a pivotal consideration, with a multidisciplinary team making the ultimate decision in the patient's best interest. Periprocedural imaging aids real-time visualization but is influenced by anaesthesia choices. A comprehensive postprocedural assessment is critical due to potential TAVR-related complications. Numerous trials have demonstrated that TAVR matches or surpasses surgery for patients with diverse surgical risk profiles, ranging from extreme to low risk. However, long-term follow-up data, particularly in low-risk cases, remains limited, and the applicability of published results to younger patients is uncertain. This review delves into key TAVR studies, pinpointing areas for potential improvement while delving into the future of this innovative procedure. Furthermore, it explores the expanding role of TAVR technology in addressing other heart valve replacement procedures.

Prevalence of Neurovascular Microemboli After Transcatheter Aortic Valve Replacement

Background

Neurolotic sequelae after transcatheter aortic valve replacement (TAVR) can cause significant morbidity and mortality. Transcranial Doppler (TCD) imaging can show real-time high intensity transient signals (HITS), which reflect active microembolization. Although it is well known that intraprocedural microembolism occurs, it is not known if this embolic phenomenon continues in the postprocedural period. We investigated whether microemboli occur post-TAVR and whether we could determine any clinical, procedural, or echocardiographic predictors.

Methods

We evaluated HITS in 51 consecutive patients undergoing unprotected TAVR with low-, intermediate-, or high-risk Society of Thoracic Surgeons score. Patients were excluded if they did not have temporal windows for insonation of the middle cerebral artery or if they were not willing to participate. Primary outcomes of HITS 24 hours post-TAVR were observed using a Philips iU22 TCD. TCD was performed at 3 time points (pre-, peri-, and post-TAVR) for each patient, before, during, and 24 hours postprocedure.

Results

While no HITS were detected in any of the patients preoperatively, all patients had HITS during the procedure. Interestingly, 56.8% had HITS 24 hours post-TAVR. One patient with HITS post-TAVR had a stroke 48 hours after TAVR.

Conclusion

We observed a high prevalence of microemboli 24 hours post-TAVR. None of the predictors for intraprocedural microembolism seemed to play an important role for post-TAVR microemboli.

Cerebral embolic protection during transcatheter heart interventions

Stroke remains a devastating complication of transcatheter aortic valve replacement (TAVR), with the incidence of clinically apparent stroke seemingly fixed at around 3% despite TAVR's significant evolution during the past decade. Embolic showers of debris (calcium, atheroma, valve material, foreign material) are captured in the majority of patients who have TAVR using a filter-based cerebral embolic protection device (CEPD). Additionally, in systematic brain imaging studies, the majority of patients receiving TAVR exhibit new cerebral lesions. Mechanistic studies have shown reductions in the volume of new cerebral lesions using CEPDs, yet the first randomised trial powered for periprocedural stroke within 72 hours of a transfemoral TAVR failed to meet its primary endpoint of showing superiority of the SENTINEL CEPD. The present review summarises the clinicopathological rationale for the development of CEPDs, the evidence behind these devices to date and the emerging recognition of cerebral embolisation in many non-TAVR transcatheter procedures. Given the uniqueness of each of the various CEPDs under development, specific trials tailored to their designs will need to be undertaken to broaden the CEPD field, in addition to evaluating the role of CEPD in non-TAVR transcatheter heart interventions. Importantly, the cost-effectiveness of these devices will require assessment to broaden the adoption of CEPDs globally.

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.

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.

Stroke prevention during and after transcatheter aortic valve implantation: From cerebral protection devices to antithrombotic management

Since its conception, transcatheter aortic valve implantation (TAVI) has undergone important improvements both in the implantation technique and in transcatheter devices, allowing an enthusiastic adoption of this therapeutic approach in a wide population of patients previously without a surgical option and managed conservatively. Nowadays, patients with severe symptomatic aortic stenosis are typically managed with TAVI, regardless of their risk to surgery, improving the prognosis of patients and thus achieving an exponential global expansion of its use. However, thromboembolic and hemorrhagic complications remain a latent concern in TAVI recipients. Both complications can appear simultaneously in the periprocedural period or during the follow-up, and when minor, they resolved without apparent sequelae, but in a relevant percentage of cases, they are devastating, overshadowing the benefit achieved with TAVI. Our review outlines the etiology and incidence of thromboembolic complications associated with TAVI, the main current strategies for their prevention, and the implications of its pharmacological management at the follow-up in a TAVI population, mostly frail and predisposed to bleeding complications.

Outcome of left atrial appendage closure using cerebral protection system for thrombosis: no patient left behind

BACKGROUND

Left atrial appendage (LAA) thrombosis increases the risk of stroke and its management has to be assessed. The aim of the present study is to evaluate short and long-term safety and efficacy of a standardized approach of percutaneous LAA closure (LAAC) routinely using a cerebral protection device (CPD) in patients with LAA thrombosis or sludge (LAAT).

METHODS

We prospectively enrolled 14 consecutive patients with atrial fibrillation complicated by LAAT presenting in a high-volume tertiary center. In seven patients (50%) LAAT was found after anticoagulant withdrawal for severe bleedings and in the remaining half LAAT was found despite appropriate anticoagulant therapy. All patients were treated with a standardized interventional approach of LAAC routinely using a CPD and guided by transoesophageal echocardiography.

RESULTS

Mean age was 68 ± 14 years and nine patients (64%) were male. Mean CHA₂ DS₂ -VASc and HAS-BLED scores were 3.3 ± 1.6 and 2.3 ± 1.1, respectively. Six patients (42.8%) presented organized thrombi while eight LAA sludge (57.1%). In 13 patients (92.8%) CPD was positioned through a right radial arterial access. Procedural success was achieved in all patients. In one patient we assisted to embolization of the thrombus during deployment of the device in the absence of neurological consequences. During a mean follow up of 426 ± 307 days, one patient died for non-cardiac cause while no embolic event or major bleeding were reported.

CONCLUSION

In an unselected cohort, LAAC with the systematic use of CPD was a feasible, safe and effective therapeutic option for LAAT both acutely and after long-term follow-up.

Neurologic Dysfunction and Neuroprotection in Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) is a fast-growing procedure. Expanding to low-risk patients, it has surpassed surgical aortic valve implantation in frequency and has been associated with excellent outcomes. Stroke is a devastating complication after transcatheter aortic valve implantation. Silent brain infarcts identified by diffusion-weighted magnetic resonance imaging are present in most patients following TAVI. Postoperative delirium and cognitive dysfunction are common neurologic complications. The stroke and silent brain infarcts are likely caused by particulate emboli released during the procedure. Intravascularly positioned cerebral embolic protection devices are designed to prevent debris from entering the aortic arch vessels to avoid stroke. Despite promising design, randomized clinical trials have not demonstrated a reduction in stroke in patients receiving cerebral embolic protection devices. Similarly, the association of cerebral embolic protection devices with silent brain infarcts, postoperative delirium, and cognitive dysfunction is uncertain. Monitored anesthesia care or conscious sedation is as safe as general anesthesia and is associated with lower cost, but different anesthetic techniques have not been shown to decrease stroke risk, postoperative delirium, or cognitive dysfunction. Anesthesiologists play important roles in providing perioperative care including management of neurologic events in patients undergoing TAVI. Large randomized clinical trials are needed that focus on the correlation between perioperative interventions and neurologic outcomes.

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

INTRODUCTION

Cerebrovascular events are one of the most serious consequences after transcatheter aortic valve replacement (TAVR). More than half of the cerebrovascular events following TAVR are due to procedure-related emboli. Embolic protection devices (EPDs) have the potential to decrease cerebrovascular events during TAVR procedure. However, randomized controlled trials (RCTs) have not conclusively determined if EPDs are effective, likely because of small number of patients enrolled. However, meta-analyses and propensity-matched analyses from large registries have shown efficacy and suggest the importance of EPDs in prevention of stroke during TAVR and perhaps other structural heart procedures.

AREAS COVERED

This review will focus on clinical and histopathologic studies examining the efficacy, safety, and histopathologic device capture findings in the presence and absence of EPDs during TAVR procedures.

EXPERT OPINION

Clinical studies have not conclusively determined the efficacy of EPDs. Current ongoing large-scale RCT (PROTECTED TAVR [NCT04149535]) has the potential to prove their efficacy. Histopathological evaluation of debris captured by EPDs contributes to our understanding of the mechanisms of TAVR procedure-related embolic events and suggests the importance of preventing cerebral embolization of debris released during this and other structural heart procedures.

Advancements in Transcatheter Aortic Valve Implantation: A Focused Update

Transcatheter aortic valve implantation (TAVI) has become the leading technique for aortic valve replacement in symptomatic patients with severe aortic stenosis with conventional surgical aortic valve replacement (SAVR) now limited to patients younger than 65-75 years due to a combination of unsuitable anatomies (calcified raphae in bicuspid valves, coexistent aneurysm of the ascending aorta) and concerns on the absence of long-term data on TAVI durability. This incredible rise is linked to technological evolutions combined with increased operator experience, which led to procedural refinements and, accordingly, to better outcomes. The article describes the main and newest technical improvements, allowing an extension of the indications (valve-in-valve procedures, intravascular lithotripsy for severely calcified iliac vessels), and a reduction of complications (stroke, pacemaker implantation, aortic regurgitation).

A Review of the Partner Trials

Aortic stenosis (AS) of moderate or greater severity has an estimated prevalence of 5% in people older than 65 years. Survival is poor after onset of symptoms, and surgical aortic valve replacement was the gold-standard treatment for decades. However, more than one-third of patients with symptomatic AS were untreated due to high surgical risk, exposing a clinical need for a less invasive therapy for aortic valve stenosis. The PARTNER trials were pivotal in presenting robust evidence for the safety, feasibility, and efficacy of transcatheter aortic valve replacement in the management of AS and paved the way for clinical use worldwide.

Cerebral Protection Devices during Transcatheter Interventions: Indications, Benefits, and Limitations

Purpose of Review

Stroke remains a devastating complication of cardiovascular interventions. This review is going to discuss stroke rates and outcomes in different cardiovascular procedures with a highlight on the current evidence for the use of cerebral protection devices (CPD).

Recent Findings

Depending on the quality of neurological assessment, stroke occurs in up to 9.1% after TAVI, 3.9% after mitral clipping, 3.1% in LAAO patients, 0.4% after PCIs, and 1.8% after catheter ablation. CPDs are available for routine use. They are easy to use in most anatomies, feasible, and safe. Data on clinical impact and stroke reduction from RCTs are still missing.

Summary

Most evidence for the routine use of CPDs exists in TAVI patients, who are at the highest risk. The PROTECTED TAVI RCT will shed more light on the clinical impact of CPD-use in TAVI patients. In other cardiovascular procedures like mitral clipping, PCIs, and ablation, the current data do not support the routine use of CPDs in these patients.