Cerebral embolic protection devices during transcatheter aortic valve implantation: clinical versus silent embolism

Heart Transplantation and Thromboembolic Risk In Patients With Percutaneous Aortic Valve Prosthesis and Left Ventricular Assist Device: A Case Report

Transcatheter aortic valve replacements have become a good option for patients with aortic valve disease and high surgical risk. Thromboembolism is reported as a relatively common complication of Transcatheter aortic valve replacement. This risk may be increased in patients who have left ventricular assist devices, as valve motion is drastically reduced. We present the case of a 65-year-old man with a history of alcoholism and valvular cardiomyopathy (severe chronic aortic insufficiency) with severe left ventricular dysfunction. Improvement in ventricular function followed the cessation of alcohol consumption, but still in poor clinical condition. Due to his high surgical risk, it was decided to implant a percutaneous aortic valve to treat the valve deficiency. Two months later, he suffered from a first episode of embolic stroke, which he successfully recovered. Despite the treatment, his clinical status did not improve (INTERMACS 3-4), and he was referred for heart transplantation. A left ventricular assist device was implanted as a bridge to the transplant. While on the waiting list, he suffered from other 3 episodes of stroke, 2 of them requiring mechanical thrombectomy. Finally, his transplant was performed with a favorable postoperative clinical course. Heart transplantation may be feasible in patients with multiple intracardiac devices in left chambers, although we must be aware of the increased thromboembolic risk, especially when used in combination.

Fighting Cardiac Thromboembolism during Transcatheter Procedures: An Update on the Use of Cerebral Protection Devices in Cath Labs and EP Labs

Intraprocedural stroke is a well-documented and feared potential risk of cardiovascular transcatheter procedures (TPs). Moreover, subclinical neurological events or covert central nervous system infarctions are concerns related to the development of dementia, future stroke, cognitive decline, and increased risk of mortality. Cerebral protection devices (CPDs) were developed to mitigate the risk of cardioembolic embolism during TPs. They are mechanical barriers designed to cover the ostium of the supra-aortic branches in the aortic arch, but newer devices are able to protect the descending aorta. CPDs have been mainly designed and tested to provide cerebral protection during transcatheter aortic valve replacement (TAVR), but their use in both Catheterization and Electrophysiology laboratories is rapidly increasing. CPDs have allowed us to perform procedures that were previously contraindicated due to high thromboembolic risk, such as in cases of intracardiac thrombosis identified at preprocedural assessment. However, several concerns related to their employment have to be defined. The selection of patients at high risk of thromboembolism is still a subjective choice of each center. The aim of this review is to update the evidence on the use of CPDs in either Cath labs or EP labs, providing an overview of their structural characteristics. Future perspectives focusing on their possible future employment are also discussed.

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.

Antithrombotic Therapy Following Transcatheter Aortic Valve Replacement

Due to a large technical improvement in the past decade, transcatheter aortic valve replacement (TAVR) has expanded to lower-surgical-risk patients with symptomatic and severe aortic stenosis. While mortality rates related to TAVR are decreasing, the prognosis of patients is still impacted by ischemic and bleeding complications, and defining the optimal antithrombotic regimen remains a priority. Recent randomized control trials reported lower bleeding rates with an equivalent risk in ischemic outcomes with single antiplatelet therapy (SAPT) when compared to dual antiplatelet therapy (DAPT) in patients without an underlying indication for anticoagulation. In patients requiring lifelong oral anticoagulation (OAC), the association of OAC plus antiplatelet therapy leads to a higher risk of bleeding events with no advantages on mortality or ischemic outcomes. Considering these data, guidelines have recently been updated and now recommend SAPT and OAC alone for TAVR patients without and with a long-term indication for anticoagulation. Whether a direct oral anticoagulant or vitamin K antagonist provides better outcomes in patients in need of anticoagulation remains uncertain, as recent trials showed a similar impact on ischemic and bleeding outcomes with apixaban but higher gastrointestinal bleeding with edoxaban. This review aims to summarize the most recently published data in the field, as well as describe unresolved issues.

Management and outcomes of patients with left atrial appendage thrombus prior to percutaneous closure

Objective

Left atrial appendage (LAA) thrombus has heretofore been considered a contraindication to percutaneous LAA closure (LAAC). Data regarding its management are very limited. The aim of this study was to analyse the medical and invasive treatment of patients referred for LAAC in the presence of LAA thrombus.

Methods

This multicentre observational registry included 126 consecutive patients referred for LAAC with LAA thrombus on preprocedural imaging. Treatment strategies included intensification of antithrombotic therapy (IAT) or direct LAAC. The primary and secondary endpoints were a composite of bleeding, stroke and death at 18 months, and procedural success, respectively.

Results

IAT was the preferred strategy in 57.9% of patients, with total thrombus resolution observed in 60.3% and 75.3% after initial and subsequent IAT, respectively. Bleeding complications and stroke during IAT occurred in 9.6% and 2.9%, respectively, compared with 3.8% bleeding and no embolic events in the direct LAAC group before the procedure. Procedural success was 90.5% (96.2% vs 86.3% in direct LAAC and IAT group, respectively, p=0.072), without cases of in-hospital thromboembolic complications. The primary endpoint occurred in 29.3% and device-related thrombosis was found in 12.8%, without significant difference according to treatment strategy. Bleeding complications at 18 months occurred in 22.5% vs 10.5% in the IAT and direct LAAC group, respectively (p=0.102).

Conclusion

In the presence of LAA thrombus, IAT was the initial management strategy in half of our cohort, with initial thrombus resolution in 60% of these, but with a relatively high bleeding rate (~10%). Direct LAAC was feasible, with high procedural success and absence of periprocedural embolic complications. However, a high rate of device-related thrombosis was detected during follow-up.

The Use and Outcomes of Cerebral Protection Devices for Patients Undergoing Transfemoral Transcatheter Aortic Valve Replacement in Clinical Practice

OBJECTIVES

This study hypothesized that cerebral protection prevents strokes in patients undergoing transfemoral transcatheter aortic valve replacement (TAVR) in clinical practice.

BACKGROUND

Preventing strokes is an important aim in TAVR procedures. Embolic protection devices may protect against cardiac embolism during TAVR, but their use and outcomes in clinical practice remain controversial.

METHODS

Isolated transfemoral TAVR procedures performed in Germany with or without cerebral protection devices were extracted from a comprehensive nationwide billing dataset.

RESULTS

A total of 41,654 TAVR procedures performed between 2015 and 2017 were analyzed. The overall share of procedures incorporating cerebral protection devices was 3.8%. Patients receiving cerebral protection devices were at increased operative risk (European System for Cardiac Operative Risk Evaluation score 13.8 vs. 14.7; p < 0.001) but of lower age (81.1 vs. 80.6 years; p = 0.001). To compare outcomes that may be related to the use of cerebral protection devices, a propensity score comparison was performed. The use of a cerebral protection device did not reduce the risk for stroke (adjusted risk difference [aRD]: +0.88%; 95% confidence interval [CI]: -0.07% to 1.83%; p = 0.069) or the risk for developing delirium (aRD: +1.31%; 95% CI: -0.28% to 2.89%; p = 0.106) as a sign of acute brain failure. Although brain damage could not be prevented, in-hospital mortality was lower in the group receiving a cerebral protection device (aRD: -0.76%; 95% CI: -1.46% to -0.06%; p = 0.034).

CONCLUSIONS

In this large national database, cerebral embolic protection devices were infrequently used during TAVR procedures. Device use was associated with lower mortality but not a reduction in stroke or delirium. Future studies are needed to confirm these findings.

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).

Feasibility and Safety of Cerebral Embolic Protection Device Insertion in Bovine Aortic Arch Anatomy

Background: Cerebral embolic protection devices (CEPDs) have emerged as a mechanical barrier to prevent debris from reaching the cerebral vasculature, potentially reducing stroke incidence. Bovine aortic arch (BAA) is the most common arch variant and represents challenge anatomy for CEPD insertion during transcatheter aortic valve replacement (TAVR). Methods: Cohort study reporting the Sentinel^TM Cerebral Protection System insertion’s feasibility and safety in 165 adult patients submitted to a transfemoral TAVR procedure from April 2019 to April 2020. Patients were divided into 2 groups: (1) BAA; (2) non-BAA. Results: Median age, EuroScore II, and STS score were 79 years (74–84), 2.9% (1.7–6.2), and 2.2% (1.6–3.2), respectively. BAA was present in 12% of cases. Successful two-filter insertion was 86.6% (89% non-BAA vs. 65% BAA; p = 0.002), and debris was captured in 95% (94% non-BAA vs. 95% BAA; p = 0.594). No procedural or vascular complications associated with Sentinel insertion and no intraprocedural strokes were reported. There were two postprocedural non-disabling strokes, both in non-BAA. Conclusion: This study demonstrated Sentinel insertion feasibility and safety in BAA. No procedural and access complications related to Sentinel deployment were reported. Being aware of the bovine arch prevalence and having the techniques to navigate through it allows operators to successfully use CEPDs in this anatomy.

Current issues in transcatheter aortic valve replacement

Aortic stenosis is the most common valvular disease worldwide. With transcatheter aortic valve replacement (TAVR) being increasingly expanded to lower-risk populations, several challenging issues remain to be solved. The present review aims at discussing modern approaches to such issues as well as the current status of TAVR. TAVR has undergone several developments in the recent years: an increased use of transfemoral access, the development of prostheses in order to adapt to challenging anatomies, improved delivery systems with repositioning features, and outer skirts aiming at reducing paravalvular leak. The indication of TAVR is increasingly being expanded to patients with lower surgical risk. The main clinical trials supporting such expansion are reviewed and the latest data on low-risk patients are discussed. A number of challenges need still to be addressed and are also reviewed in this paper: the need for updated international guidelines including the latest evidence; a reduction of main complications such as permanent pacemaker implantation, paravalvular leak, and stroke (and its potential prevention by using anti-embolic protection devices); the appropriate role of TAVR in patients with concomitant cardiac ischemic disease; and durability of bio-prosthetic implanted valves. Finally, the future perspectives for TAVR use and next device developments are discussed.

Cerebral protection devices for transcatheter aortic valve replacement

Aortic stenosis is the most prevalent primary valve disease in developed countries. Its prevalence is increasing due to population aging. Transcatheter aortic valve replacement (TAVR) is a sterling therapy for symptomatic patients with severe aortic stenosis and high or intermediate surgery risk. The number of procedures has increased exponentially expanding to younger and lower risk patients. Despite new-generation TAVR devices and enhanced operator skills, cerebrovascular events (CVEs) carry on being one of the most severe complications, increasing morbi-mortality. CVE might be under reported because there are few studies with rigorous neurological clinical assessment. Several imaging studies show most of CVE after TAVR has a probable embolic etiology. The risk of CVE ranges from 2.7% to 5.5% at 30 days. As TAVR expands to younger and lower risk patients, the prevention of stroke plays an increasingly important role. Cerebral protection devices (CPD) were designed to reduce the risk of CVE during TAVR. This review describes the scientific evidence on CVE after TAVR and summarizes the performance and results of the main CPDs.