Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Implantation

Computational Investigation of Vessel Injury Due to Catheter Tracking During Transcatheter Aortic Valve Replacement

Catheter reaction forces during transcatheter valve replacement (TAVR) may result in injury to the vessel or plaque rupture, triggering distal embolization or thrombosis. In vitro test methods represent the arterial wall using synthetic proxies to determine catheter reaction forces during tracking, but whether they can account for reaction forces within the compliant aortic wall tissue in vivo is unknown. Moreover, the role of plaque inclusions is not well understood. Computational approaches have predicted the impact of TAVR positioning, migration, and leaflet distortion, but have not yet been applied to investigate aortic wall reaction forces and stresses during catheter tracking. In this study, we investigate the role that catheter design and aorta and plaque mechanical properties have on the risk of plaque rupture during TAVR catheter delivery. We report that, for trackability testing, a rigid test model provides a reasonable estimation of the peak reaction forces experienced during catheter tracking within compliant vessels. We investigated the risk of rupture of both the aortic tissue and calcified plaques. We report that there was no risk of diseased aortic tissue rupture based on an accepted aortic tissue stress threshold (4.2 MPa). However, we report that both the aortic and plaque tissue exceed a rupture stress threshold (300 kPa) with and without the presence of stiff and soft plaque inclusions. We also highlight the potential risks associated with shorter catheter tips during catheter tracking and demonstrate that increasing the contact surface will reduce peak contact pressures experienced in the tissue.

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.

Association of Bovine Arch Anatomy With Incident Stroke After Transcatheter Aortic Valve Replacement

BACKGROUND

Acute ischemic stroke complicates 2% to 3% of transcatheter aortic valve replacements (TAVRs). This study aimed to identify the aortic anatomic correlates in patients after TAVR stroke.

METHODS AND RESULTS

This is a single-center, retrospective study of patients who underwent TAVR at the Mayo Clinic between 2012 and 2022. The aortic arch morphology was determined via a manual review of the pre-TAVR computed tomography images. An "a priori" approach was used to select the covariates for the following: (1) the logistic regression model assessing the association between a bovine arch and periprocedural stroke (defined as stroke within 7 days after TAVR); and (2) the Cox proportional hazards regression model assessing the association between a bovine arch and long-term stroke after TAVR. A total of 2775 patients were included (59.6% men; 97.8% White race; mean±SD age, 79.3±8.4 years), of whom 495 (17.8%) had a bovine arch morphology. Fifty-seven patients (1.7%) experienced a periprocedural stroke. The incidence of acute stroke was significantly higher among patients with a bovine arch compared with those with a nonbovine arch (3.6% versus 1.7%; P=0.01). After adjustment, a bovine arch was independently associated with increased periprocedural strokes (adjusted odds ratio, 2.16 [95% CI, 1.22-3.83]). At a median follow-up of 2.7 years, the overall incidence of post-TAVR stroke was 6.0% and was significantly higher in patients with a bovine arch even after adjusting for potential confounders (10.5% versus 5.0%; adjusted hazard ratio, 2.11 [95% CI, 1.51-2.93]; P<0.001).

CONCLUSIONS

A bovine arch anatomy is associated with a significantly higher risk of periprocedural and long-term stroke after TAVR.

Site Variability in Cerebral Embolic Protection for Transcatheter Aortic Valve Implantation and Association With Outcomes

Background

The effectiveness of cerebral embolic protection devices (CEPD) in mitigating stroke after transcatheter aortic valve implantation (TAVI) remains uncertain, and therefore CEPD may be utilized differently across US hospitals. This study aims to characterize the hospital-level pattern of CEPD use during TAVI in the US and its association with outcomes.

Methods

Patients treated with nontransapical TAVI in the 2019 Nationwide Readmissions Database were included. Hospitals were categorized as CEPD non-users and CEPD users. The following outcomes were compared: the composite of in-hospital stroke or transient ischemic attack (TIA), in-hospital ischemic stroke, death, and cost of hospitalization. Logistic regression models were used for risk adjustment of clinical outcomes.

Results

Of 41,822 TAVI encounters, CEPD was used in 10.6% (n = 4422). Out of 392 hospitals, 65.8% were CEPD non-user hospitals and 34.2% were CEPD users. No difference was observed between CEPD non-users and CEPD users in the risk of in-hospital stroke or TIA (adjusted odds ratio (OR) = 0.99 [0.86-1.15]), ischemic stroke (adjusted OR = 1.00 [0.85-1.18]), or in-hospital death (adjusted OR = 0.86 [0.71-1.03]). The cost of hospitalization was lower in CEPD non-users.

Conclusions

Two-thirds of hospitals in the US do not use CEPD for TAVI, and no significant difference was observed in neurologic outcomes among patients treated at CEPD non-user and CEPD user hospitals.

Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Replacement: A Meta-analysis of Randomized Controlled Trials

Background

Stroke is a feared complication of transcatheter aortic valve replacement (TAVR), which embolic protection devices (EPDs) may mitigate. This systematic review and meta-analysis synthesized randomized controlled trials (RCTs) to evaluate the effect of EPDs in TAVR.

Methods

All RCTs comparing EPDs with control during TAVR were systematically identified. Prespecified primary end points were all stroke, disabling stroke, nondisabling stroke, and all-cause mortality. Safety and neuroimaging parameters were assessed. Sensitivity analyses were stratified by EPD type. Study registration was a priori (CRD42022377939).

Results

Eight trials randomizing 4043 patients were included. There was no significant difference between EPDs and control for all stroke (relative risk [RR], 0.88; 95% CI, 0.65-1.18; P = .39; I2 = 0%), disabling stroke (RR, 0.67; 95% CI, 0.31-1.46; P = .32; I2 = 8.6%), nondisabling stroke (RR, 0.99; 95% CI, 0.71-1.40; P = .97; I2 = 0%), or all-cause mortality (RR, 0.87; 95% CI, 0.43-1.78; P = .71; I2 = 2.3%). There were no differences in safety end points of bleeding, vascular complications, or acute kidney injury. EPDs did not result in differences in total lesion volume or the number of new lesions. The Sentinel EPD significantly reduced the risk of disabling stroke (RR, 0.42; 95% CI, 0.20-0.88; P = .022; I2 = 0%) but did not affect all stroke, nondisabling stroke, or all-cause mortality.

Conclusions

The totality of randomized data for EPDs during TAVR demonstrated no safety concerns or significant differences in clinical or neuroimaging end points. Analyses restricted to the Sentinel EPD demonstrated large, clinically meaningful reductions in disabling stroke. Ongoing RCTs may help validate these results.

Modifications in ocular microperfusion after transcatheter aortic valve implantation

Cerebral embolization is a known complication of transcatheter aortic valve implantation (TAVI) but the effect of the procedure on the ocular perfusion is currently unclear. Thus, we investigated post-procedural morphologic and perfusion changes of the retina and choroid, using optical coherence tomography angiography (OCTA) and color fundus photography (CFP) in a prospective cohort study. Ophthalmic examinations were conducted pre- and post-TAVI. OCTA images were analyzed quantitatively based on vessel density and skeleton density of the superficial and deep retinal plexus as well as the signal intensity and flow deficits in the choriocapillaris. CFP images were assessed for presence of acute retinal ischemia, optic nerve swelling, vessel emboli, hemorrhages and cotton wool spots. Data was analyzed using linear mixed models. Twenty patients (9 women; 11 men) at a mean age of 81 ± 6 years were included. Pre- and post-interventional ocular imaging data were available for 32 eyes. The analysis revealed a significant impairment of the choriocapillaris perfusion after TAVI with an increased proportion of flow deficits (p = 0.044). When controlling for blood pressure, the average size of choriocapillaris flow voids was significantly increased (systolic and diastolic, p = 0.039 and 0.029). Qualitatively, focal areas of retinal ischemia were detected on OCTA in 33% of participants. Silent emboli or cotton wool spots were identified on CFP in 21%. Our findings indicate a reduced choroidal perfusion as well as areas of retinal ischemia and embolization in a considerable proportion of patients following TAVI. Pending confirmation in a larger sample, these complications merit monitoring as well as inclusion in consent procedures for TAVI.

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 during transcatheter aortic valve replacement: a systematic review and meta-analysis of propensity score matched and randomized controlled trials using the Sentinel cerebral embolic protection device

BACKGROUND

The Sentinel cerebral embolic protection device (CEP) aims to reduce the risk of stroke during transcatheter aortic valve replacement (TAVR). We performed a systematic review and meta-analysis of propensity score matched (PSM) and randomized controlled trials (RCT) investigating the effect of the Sentinel CEP to prevent strokes during TAVR.

METHODS

Eligible trials were searched through PubMed, ISI Web of science databases, Cochrane database, and proceedings of major congresses. Primary outcome was stroke. Secondary outcomes included all-cause mortality, major or life-threatening bleeding, major vascular complications and acute kidney injury at discharge. Fixed and random effect models were used to calculate the pooled risk ratio (RR) with 95% confidence intervals (CI) and absolute risk difference (ARD).

RESULTS

A total of 4066 patients from 4 RCTs (3'506 patients) and 1 PSM study (560 patients) were included. Use of Sentinel CEP was successful in 92% of patients and was associated with a significantly lower risk of stroke (RR: 0.67, 95% CI: 0.48-0.95, p = 0.02. ARD: -1.3%, 95% CI: -2.3 - -0.2, p = 0.02, number needed to treat (NNT) = 77), and a reduced risk of disabling stroke (RR: 0.33, 95% CI: 0.17-0.65. ARD: -0.9%, 95% CI: -1.5 - -0.3, p = 0.004, NNT = 111). Use of Sentinel CEP was associated with a lower risk of major or life-threatening bleeding (RR: 0.37, 95% CI: 0.16-0.87, p = 0.02). Risk for nondisabling stroke (RR: 0.93, 95% CI: 0.62-1.40, p = 0.73), all-cause mortality (RR: 0.70, 95% CI: 0.35-1.40, p = 0.31), major vascular complications (RR: 0.74, 95% CI: 0.33-1.67, p = 0.47) and acute kidney injury (RR: 0.74, 95% CI: 0.37-1.50, p = 0.40) were similar.

CONCLUSIONS

The use of CEP during TAVR was associated with lower risks of any stroke and disabling stroke with an NNT of 77 and 111, respectively.

Routine cerebral embolic protection in transcatheter aortic valve implantation: rationale and design of the randomised British Heart Foundation PROTECT-TAVI trial

Transcatheter aortic valve implantation (TAVI) is an established treatment for aortic stenosis. Cerebral embolic protection (CEP) devices may impact periprocedural stroke by capturing debris destined for the brain. However, there is a lack of high-quality randomised trial evidence supporting the use of CEP during TAVI. The British Heart Foundation (BHF) PROTECT-TAVI trial will address whether the routine use of CEP reduces the incidence of stroke in patients undergoing TAVI. BHF PROTECT-TAVI is a prospective, open-label, outcome-adjudicated, multicentre randomised controlled trial. The trial is open to all adult patients scheduled for TAVI at participating specialist cardiac centres across the United Kingdom who are able to receive the CEP device. The trial will recruit 7,730 participants. Participants will be randomised in a 1:1 ratio to undergo TAVI with CEP or TAVI without CEP (standard of care). The primary outcome is the incidence of stroke at 72 hours post-TAVI. Key secondary outcomes include the incidence of stroke and all-cause mortality up to 12 months post-TAVI, disability and cognitive outcomes, stroke severity, access site complications and a health economics analysis. The sample size of 7,730 participants has 80% power to detect a 33% relative risk reduction from a 3% incidence of the primary outcome in the controls. Trial recruitment commenced in October 2020. As of October 2022, 3,068 patients have been enrolled. BHF PROTECT-TAVI is designed to provide definitive evidence on the clinical efficacy and cost-effectiveness of using routine CEP with the SENTINEL device to reduce stroke in TAVI.

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 after transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with symptomatic severe aortic stenosis across the entire spectrum of surgical risk. TAVI conveys some risk for thrombotic complications, requiring antithrombotic drugs for their prevention. Bleeding events represent the major drawback of antithrombotic therapy, which should be carefully tailored over the individual patient's risk profile.

AREAS COVERED

This review aimed at exploring the rationale for the adoption of a tailored antithrombotic therapy after successful TAVI, with a description and analysis of common complications and their impact on therapy selection. In addition, we aimed at reviewing and discussing current knowledge in this area, with a main focus on the high-quality evidence supporting latest guideline recommendations. Finally, ongoing studies and future directions on antithrombotic therapy after TAVI were outlined.

EXPERT OPINION

Initial experience with antithrombotic therapy after TAVI was derived from percutaneous coronary intervention practice. Accruing evidence in the field led to the current monotherapy paradigm, which prioritizes oral anticoagulant and single antiplatelet therapy in patients with or without an established indication for long-term anticoagulation, respectively. Future studies will investigate the role of alternative antithrombotic strategies to improve clinical outcomes of TAVI patients by minimizing both thrombotic and bleeding complications.

Aortic Valve Calcium Score Is Associated With Acute Stroke in Transcatheter Aortic Valve Replacement Patients

Background

Transcatheter aortic valve replacement (TAVR) is the treatment of choice for patients with severe aortic stenosis who are at a moderate or higher surgical risk. Stroke is a recognised and serious complication of TAVR, and it is important to identify patients at higher stroke risk. This study aims to discover if aortic valve calcium score calculated from pre-TAVR computed tomography is associated with acute stroke in TAVR patients.

Methods

We conducted a retrospective, observational cohort study of 433 consecutive patients undergoing TAVR between January 2017 and December 2019 at the Hammersmith Hospital.

Results

This cohort had a median age of 83 years (interquartile range, 78-87), and 52.7% were male. Fifty-two patients (12.0%) had a history of previous stroke or transient ischemic attack. Median aortic valve calcium score was 2145 (interquartile range, 1427-3247) Agatston units. Twenty-two patients had a stroke up to the time of discharge (5.1%). In a logistic regression model, aortic valve calcium score was significantly associated with acute stroke (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.01-1.53; P = .02). Acute stroke was also significantly associated with peripheral arterial disease (OR, 4.32; 95% CI, 1.65-10.65; P = .0018) and a longer procedure time (OR, 1.01; 95% CI, 1.00-1.02; P = .0006).

Conclusions

Aortic valve calcium score from pre-TAVR computed tomography is an independent risk factor for acute stroke in the TAVR population. This is an additional clinical value of the pre-TAVR aortic valve calcium score and should be considered when discussing periprocedural stroke risk.

Percutaneous versus surgical transaxillary access for transcatheter aortic valve replacement: a propensity-matched analysis of the US experience

BACKGROUND

As transaxillary (TAx) access has become the most common alternative to transfemoral (TF) transcatheter aortic valve replacement (TAVR), there is increasing use of a percutaneous approach.

AIMS

This study sought to determine whether there are differences in outcomes using a percutaneous access versus cutdown for TAx TAVR.

METHODS

Using data from the STS/ACC TVT Registry, consecutive patients undergoing TAx TAVR with balloon-expandable valves between July 2015 and December 2020 were included. Propensity score-based matching was performed to evaluate the association between method of TAx access and outcomes.

RESULTS

Of 4,219 patients, 1,140 (27.0%) underwent percutaneous access and 3,079 (73.0%) had surgical cutdown for TAx TAVR, with the proportion of percutaneous cases increasing over time. After propensity matching, there were no significant baseline differences between patients undergoing TAx access by either approach. At 30 days, there were similar rates of all-cause mortality (4.8% in percutaneous patients vs 4.1% in surgical patients; p=0.40) and stroke (7.7% vs 6.5%; p=0.25). Those undergoing percutaneous TAx access were more likely to receive conscious sedation and have less need for the intensive care unit (ICU). Percutaneous access was associated with a higher rate of major vascular complication (3.0% vs 1.5% in surgical patients; p=0.02) but not life-threatening bleeding (0.3% vs 0.1%; p=0.31).

CONCLUSIONS

This study supports the safety and efficacy of percutaneous TAx TAVR compared to traditional surgical cutdown. Percutaneous access was associated with a shorter ICU stay and a higher rate of major vascular complication without an increase in life-threatening bleeding.

Successful transfemoral-transcatheter aortic valve replacement in high-risk patients with a grade 4 atheroma in the ascending aorta: cerebral protection with a filter device

Perioperative stroke is one of the most serious complications after transcatheter aortic valve replacement (TAVR), and it should be especially noted in patients with an atheroma in the ascending aorta. Here, we report the first experience of transfemoral (TF)-TAVR with the insertion of a filter device for two patients with severe aortic stenosis who were incidentally detected a grade 4 atheroma in the ascending aorta preoperatively. The patients had a favorable postoperative course without any cerebrovascular events or procedure-related complications.

Cerebral Embolic Protection during Transcatheter Aortic Valve Implantation: Updated Systemic Review and Meta-Analysis

In patient undergoing transcatheter aortic valve implantation (TAVI), stroke remains a potentially devastating complication associated with significant morbidity, and mortality. To reduce the risk of stroke, cerebral protection devices (CPD) were developed to prevent debris from embolizing to the brain during TAVI. We performed a systematic review and meta-analysis to determine the safety and efficacy of CPD in TAVI. The MEDLINE (PubMed, Ovid) and Cochrane databases were queried with various combinations of medical subject headings to identify relevant articles. Statistical analysis was performed using a random-effects model to calculate unadjusted odds ratio (OR), including subgroup analyses based on follow-up duration, study design, and type of CPD. Using a pooled analysis, CPD was associated with a significant reduction in major adverse cardiovascular events MACE (OR 0.75, 95% CI 0.70-0.81, P < 0.01), mortality (OR 0.65, 95% CI 0.58-0.74, P < 0.01) and stroke (OR 0.84, 95% CI 0.76-0.93, P < 0.01) in patients undergoing TAVI. Similarly, on MRI volume per lesion were lower for patients with CPD use. No significant difference was observed in acute kidney injury (OR 0.75, 95% CI 0.42-1.37, P = 0.68), bleeding (OR 0.92, 95% CI 0.71-1.20, P = 0.55) or vascular complications (OR 0.90, 95% CI 0.62-1.31, P = 0.6) for patients undergoing TAVI with CPD. In conclusion, CPD device use in TAVI is associated with a reduction of MACE, mortality, and stroke compared with patients undergoing TAVI without CPD. However, the significant reduction in mortality is driven mainly by observational studies.

Safety and efficacy of cerebral embolic protection devices in patients undergoing transcatheter aortic valve replacement: a meta-analysis of in-hospital outcomes

The evidence regarding the impact of cerebral embolic protection devices (EPDs) on outcomes following transcatheter aortic valve replacement (TAVR) is limited. The objective of this study was to evaluate in-hospital outcomes with the use of cerebral EPDs in TAVR. We performed a comprehensive EMBASE and PUBMED search to investigate randomized control studies or propensity score-matched retrospective studies which assessed patients undergoing TAVR with or without EPD up to April 2021. Endpoints of interest were in-hospital mortality, stroke, acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. Ten studies involving 173,002 patients with EPD (n = 16,898, 9.8%) and those without (n = 156,104, 90.2%) fulfilled the inclusion criteria. The use of EPD was associated with significantly lower risk of in-hospital stroke (odds ratio [95% confidential interval]: 0.64 [0.46; 0.89]), but similar rate of in-hospital mortality (odds ratio [95% confidential interval]: 0.75 [0.54; 1.05]). No differences were observed in acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. EPD during TAVR was associated with lower in-hospital stroke but did not affect procedural complications and length of stay.

Clinical outcomes following transcatheter aortic valve implantation in patients with porcelain aorta

BACKGROUND

Current guidelines favor transcatheter aortic valve implantation (TAVI) over surgical aortic valve replacement in patients with porcelain aorta (PAo). The clinical relevance of PAo in patients undergoing TAVI is however incompletely understood. The purpose of this study is to evaluate clinical outcome of patients with PAo undergoing TAVI.

METHODS

Consecutive patients undergoing TAVI were enrolled in a prospective single-center registry. Presence of PAo was evaluated by ECG-gated multi-slice computed tomography prior to the intervention. The primary endpoint was disabling stroke.

RESULTS

Among 2199 patients (mean age, 82.0 ​± ​6.3 years; 1135 females [51.6%]) undergoing TAVI between August 2007 and December 2019, 114 patients (5.2%) met VARC-2 criteria for PAo. Compared to individuals without PAo, patients with PAo were younger (79.4 ​± ​7.4 years vs. 82.1 ​± ​6.2 years; p ​< ​0.001), had a lower left ventricular ejection fraction (51.8 ​± ​14.9% vs. 55.3 ​± ​14.2%; p ​= ​0.009) and higher STS-PROM Scores (6.5 ​± ​4.3% vs. 4.9 ​± ​3.4%; p ​< ​0.001). At 1 year, disabling stroke occurred more often in patients with PAo (7.2%) than in those without (3.0%) (HR_adj, 2.49; 95% CI, 1.12-5.55). The risk difference emerged within 30 days after TAVI (HR_adj, 3.70; 95% CI, 1.52-9.03), and was driven by a high PAo-associated risk of disabling stroke in patients with alternative access (HR_adj, 5.79; 95% CI, 1.38-24.3), not in those with transfemoral (HR_adj, 1.47; 95% CI 0.45-4.85).

CONCLUSIONS

TAVI patients with PAo had a more than three-fold increased risk of periprocedural disabling stroke compared to patients with no PAo. The difference was driven by a higher risk of stroke in patients treated by alternative access.

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.

Use and outcomes of cerebral embolic protection for transcatheter aortic valve replacement: A US nationwide study

BACKGROUND

Outcomes data on the use of cerebral embolic protection devices (CPDs) with transcatheter aortic valve replacement (TAVR) remain limited. Previous randomized trials were underpowered for primary outcomes of stroke prevention and mortality.

METHODS

The National Inpatient Sample and Nationwide Readmissions Database were queried from 2017 to 2018 to study utilization and inpatient mortality, neurological complications (ischemic stroke, hemorrhagic stroke, and transient ischemic attack), procedural complications, resource utilization, and 30-day readmissions with and without use of CPD. A 1:3 ratio propensity score matched model was created.

RESULTS

Among 108,315 weighted encounters, CPD was used in 4380 patients (4.0%). Adjusted mortality was lower in patients undergoing TAVR with CPD (1.3% vs. 0.5%, p < 0.01). Neurological complications (2.5% vs. 1.7%, p < 0.01), hemorrhagic stroke (0.2% vs. 0%, p < 0.01) and ischemic stroke (2.2% vs. 1.4%, p < 0.01) were also lower in TAVR with CPD. Multiple logistic regression showed CPD use was associated with lower adjusted mortality (odds ratio (OR], 0.34 [95% confidence interval [CI], 0.22-0.52), p < 0.01) and lower adjusted neurological complications (OR, 0.68 (95% CI, 0.54-0.85], p < 0.01). On adjusted analysis, 30-day all-cause readmissions (Hazard ratio, HR 0.839, [95% CI, 0.773-0.911], p < 0.01) and stroke (HR, 0.727 [95% CI, 0.554-0.955), p = 0.02) were less likely in TAVR with CPD.

CONCLUSION

We report real-world data on utilization and in-hospital outcomes of CPD use in TAVR. CPD use is associated with lower inpatient mortality, neurological, and clinical complications as compared to TAVR without CPD.

Incidence of early intra-cranial bleeding and ischaemia in adult veno-arterial extracorporeal membrane oxygenation and extracorporeal cardiopulmonary resuscitation patients: a retrospective analysis of risk factors

BACKGROUND

Cerebral complications in veno-arterial extracorporeal membrane oxygenation are known to have a strong impact on mortality and morbidity. Aim of this study is to investigate the early incidence, risk factors and in-hospital mortality of intra-cranial ischaemia and haemorrhage in adults undergoing veno-arterial extracorporeal membrane oxygenation treatment.

METHODS

This study is a single-centre retrospective analysis on adult patients undergoing veno-arterial extracorporeal membrane oxygenation for different indications. The inclusion criterion included patients with early routine cerebral computed tomography imaging during extracorporeal membrane oxygenation, with no clinical evidence of cerebral pathology prior to cannulation. Cerebral complications were grouped by aetiology and the territories of the brain's supplying arteries.

RESULTS

One hundred eighty-seven adult patients with a total of 190 veno-arterial extracorporeal membrane oxygenation treatments were included. A total of 16.3% (n = 31) had evidence of either cerebral ischaemia (11.1%) or haemorrhage (5.8%); one patient suffered from both. Cerebral computed tomography scans were performed early in median on the first day after extracorporeal membrane oxygenation cannulation; in-hospital mortality of intra-cranial ischaemia and haemorrhage was 71.4% and 45.5%, respectively. Associated with an increased risk for ischaemic lesions were cannulation of the ascending aorta, higher age, presence of an autoimmune disease and cardiac surgery prior to veno-arterial extracorporeal membrane oxygenation. An association with haemorrhagic lesions was found for a lower blood PaCO₂ at 2 hours, lower blood flow through the extracorporeal membrane oxygenation device at 2 hours, higher international normalized ratio and constantly higher activated partial thromboplastin time values as well as higher mean arterial pressures until haemorrhagic lesions were evident.

CONCLUSION

Cerebral complications are frequent in patients on veno-arterial extracorporeal membrane oxygenation and may be clinically silent events. Careful monitoring with routine neuroimaging seems to be the most appropriate diagnostic approach at present. Intra-cranial ischaemia occurs more frequent than haemorrhage and is associated with cannulation of the aorta ascendens.

Silent brain infarcts and early cognitive outcomes after transcatheter aortic valve implantation: a systematic review and meta-analysis

BACKGROUND

Silent brain infarcts (SBIs) are frequently identified after transcatheter aortic valve implantation (TAVI), when patients are screened with diffusion-weighted magnetic resonance imaging (DW-MRI). Outside the cardiac literature, SBIs have been correlated with progressive cognitive dysfunction; however, their prognostic utility after TAVI remains uncertain. This study's main goals were to explore (i) the incidence of and potential risk factors for SBI after TAVI; and (ii) the effect of SBI on early post-procedural cognitive dysfunction (PCD).

METHODS AND RESULTS

A systematic literature review was performed to identify all publications reporting SBI incidence, as detected by DW-MRI after TAVI. Silent brain infarct incidence, baseline characteristics, and the incidence of early PCD were evaluated via meta-analysis and meta-regression models. We identified 39 relevant studies encapsulating 2408 patients. Out of 2171 patients who underwent post-procedural DW-MRI, 1601 were found to have at least one new SBI (pooled effect size 0.76, 95% CI: 0.72-0.81). The incidence of reported stroke with focal neurological deficits was 3%. Meta-regression noted that diabetes, chronic renal disease, 3-Tesla MRI, and pre-dilation were associated with increased SBI risk. The prevalence of early PCD increased during follow-up, from 16% at 10.0 ± 6.3 days to 26% at 6.1 ± 1.7 months and meta-regression suggested an association between the mean number of new SBI and incidence of PCD. The use of cerebral embolic protection devices (CEPDs) appeared to decrease the volume of SBI, but not their overall incidence.

CONCLUSIONS

Silent brain infarcts are common after TAVI; and diabetes, kidney disease, and pre-dilation increase overall SBI risk. While higher numbers of new SBIs appear to adversely affect early neurocognitive outcomes, long-term follow-up studies remain necessary as TAVI expands to low-risk patient populations. The use of CEPD did not result in a significant decrease in the occurrence of SBI.

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.

Antithrombotic therapy after transcatheter aortic valve replacement: current perspective

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) has expanded as a treatment option for severe aortic stenosis throughout the surgical risk spectrum. Decreasing procedural risk and inclusion of lower risk population has shifted the focus to optimization of postprocedural management and balancing the thrombotic and bleeding complications. In this review, we outline various patient and procedure related factors affecting choice of antithrombotic therapy post TAVR and provide an update of recent development in this area.

RECENT FINDINGS

Multiple studies have confirmed the high incidence of both ischemic and bleeding complications in the early to midterm post-TAVR. In addition, new data has emerged for the role of high resolution computed tomography to detect decreased leaflet mobility and leaflet micro thrombi associated with implications for bioprosthetic valve dysfunction and cerebrovascular events post TAVR. Randomized clinical trials have reported increased bleeding with dual antiplatelet therapy (DAPT) and oral anticoagulation (OAC) plus antiplatelet therapy. These findings suggest that aspirin monotherapy or OAC monotherapy likely provides the appropriate balance for antithrombotic protection and risk of bleeding.

SUMMARY

Majority of patients undergoing TAVR have multiple comorbidities and are at increased risk of ischemic and bleeding complications. In the absence of robust clinical evidence, there is significant variability among guideline recommendations and antithrombotic therapy post TAVR across institutions. The available evidence confirms a high rate of bleeding with more potent and prolonged antithrombotic regimens without a documented benefit for clinical endpoints. The authors favor a conservative anti thrombotic approach and suggest monotherapy with aspirin or systemic anticoagulation based upon an individual's risk of thromboembolic complications. DAPT is reserved for patients with recent stenting and OAC plus aspirin is prescribed for patients with established CAD in the post TAVR setting.

Neurologic complications of nonrheumatic valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications. Cerebral embolism is the most common, since thrombus formation results from the abnormalities in the valvular surfaces and the anatomic and physiologic changes associated with valve dysfunction, including atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for long-term anticoagulation. Transcatheter aortic valve replacement (TAVR) has emerged as a nonoperative alternative to surgical aortic valve replacement for patients with intermediate or high surgical risk, and the procedure also has a risk of cerebral ischemia. In addition, anticoagulation, the mainstay of treatment to prevent cerebral embolism, has known potential for hemorrhagic complications. The emergence of new oral anticoagulants with similar effectiveness to warfarin and a better safety profile has facilitated the management of patients with atrial fibrillation. However, their application in patients with mechanical heart valves is still evolving. The prevention and management of these complications requires an understanding of their natural history to balance the risks posed by valvular heart disease, as well as the risks and benefits associated with the treatment.

Neurologic complications of heart surgery

Cardiac surgeries are commonly associated with neurologic complications. The type and complexity of the surgery, as well as patients' comorbidities, determine the risk for these complications. Awareness and swift recognition of these complications may have significant implications on management and prognosis. Recent trials resulted in an expansion of the time window to treat patients with acute ischemic stroke with intravenous thrombolysis and/or mechanical thrombectomy using advanced neuroimaging for screening. The expanded time window increases the reperfusion treatment options for patients that suffer a periprocedural ischemic stroke. Moreover, there is now limited data available to help guide management of intracerebral hemorrhage in patients undergoing treatment with anticoagulation for highly thrombogenic conditions, such as left ventricular assist devices and mechanical valves. In addition to cerebrovascular complications patients undergoing heart surgery are at increased risk for seizures, contrast toxicity, cognitive changes, psychological complications, and peripheral nerve injuries. We review the neurological complications associated with the most common cardiac surgeries and discuss clinical presentation, diagnosis and management strategies.

Short and long-term clinical impact of transcatheter aortic valve implantation in Portugal according to different access routes: Data from the Portuguese National Registry of TAVI

INTRODUCTION

The Portuguese National Registry of Transcatheter Aortic Valve Implantation records prospectively the characteristics and outcomes of transcatheter aortic valve implantation (TAVI) procedures in Portugal.

OBJECTIVES

To assess the 30-day and one-year outcomes of TAVI procedures in Portugal.

METHODS

We compared TAVI results according to the principal access used (transfemoral (TF) vs. non-transfemoral (non-TF)). Cumulative survival curves according to access route, other procedural and clinical variables were obtained. The Valve Academic Research Consortium-2 (VARC-2) composite endpoint of early (30-days) safety was assessed. VARC-2 predictors of 30-days and 1-year all-cause mortality were identified.

RESULTS

Between January 2007 and December 2018, 2346 consecutive patients underwent TAVI (2242 native, 104 valve-in-valve; mean age 81±7 years, 53.2% female, EuroSCORE-II - EuroS-II, 4.3%). Device success was 90.1% and numerically lower for non-TF (87.0%). Thirty-day all-cause mortality was 4.8%, with the TF route rendering a lower mortality rate (4.3% vs. 10.1%, p=0.001) and higher safety endpoint (86.4% vs. 72.6%, p<0.001). The one-year all-cause mortality rate was 11.4%, and was significantly lower for TF patients (10.5% vs. 19.4%, p<0.002). After multivariate analysis, peripheral artery disease, previous percutaneous coronary intervention, left ventricular dysfunction and NYHA class III-IV were independent predictors of 30-day all-cause mortality. At one-year follow-up, NYHA class III-IV, non-TF route and occurrence of life-threatening bleeding predicted mortality. Kaplan-Meier survival analysis of the first year of follow-up shows decreased survival for patients with an EuroS-II>5% (p<0.001) and who underwent non-TF TAVI (p<0.001).

CONCLUSION

Data from our national real-world registry showed that TAVI was safe and effective. The use of a non-transfemoral approach demonstrated safety in the short term. Long-term prognosis was, however, adversely associated with this route, with comorbidities and the baseline clinical status.

Prevalence, Predictors, and Mid-Term Outcomes of Non-Home Discharge After Transcatheter Aortic Valve Implantation

Background: Transcatheter aortic valve implantation (TAVI) has been widely used as a valued alternative to surgical aortic valve replacement. In cardiovascular surgeries, discharge disposition has been widely investigated. We examined the prevalence and predictors of non-home discharge after TAVI, and the prognosis based on discharge destination. Methods and Results: We retrospectively analyzed 732 consecutive patients undergoing TAVI, and divided them into 2 groups: the home group (discharged directly home; n=678 [92.6%]) and the non-home group (n=54 [7.4%]). From baseline and procedural characteristics, peripheral artery disease (PAD; odds ratio [OR] 2.73; 95% confidence interval [CI] 1.25-5.97; P=0.012), previous stroke (OR 2.57; 95% CI 1.03-6.45; P=0.045), albumin level (OR 0.16 per 1-g/dL increase; 95% CI 0.07-0.39; P<0.001), and procedural stroke (OR 31.6; 95% CI 10.9-91.7; P<0.001) were independently associated with non-home discharge. In Kaplan-Meier analysis, the non-home group had worse survival than the home group (log-rank, P=0.001). In multivariate analysis, male sex, atrial fibrillation or atrial flutter, and low albumin concentrations were associated with all-cause mortality, but non-home discharge was not (P=0.18). Conclusions: Non-home discharge was recorded for 7.4% of patients undergoing TAVI, and was associated with PAD, nutritional status, and previous and procedural stroke. Non-home discharge reflects worse baseline characteristics, and may be a marker of mid-term outcome after TAVI.

Cerebral protection in left atrial appendage closure in the presence of appendage thrombosis

BACKGROUND

Presence of thrombus in the left atrial appendage (LAA) remains a severe contraindication to the percutaneous left atrial appendage closure procedure (LAAC), due to increased embolic risk. Recently, the experience developed in cerebral protection device in transcatheter aortic valve implantation (TAVI) procedure was translated in LAAC to address this issue.

AIM

To evaluate efficacy and safety of Sentinel cerebral protection system (CPS) in supporting LAAC in real-world patient with persistent LAA thrombus.

METHODS AND RESULTS

The study retrospectively enrolled consecutive patients with non-valvular atrial fibrillation (NVAF) and thrombus in LAA who underwent LAAC supported by Sentinel CPS in seven European high-volume centres. Twenty-seven patients were included with a median age of 69.1 ± 9.7 years old, with median CHA₂ DS₂ -VASc and HAS-BLEED scores 3 [2-5] and 3 [2.75-4], respectively. Technical and procedural success was achieved in all patients. No periprocedural TIA, stroke, or supra-aortic trunks dissection was recorded.

CONCLUSIONS

In this multicenter registry, LAAC supported by Sentinel CPS in patients with LAA persistent thrombus seems to be a safe and efficacious treatment.

Insights on Embolic Protection, Repositioning, and Stroke: A Subanalysis of the RESPOND Study

RESPOND is a prospective, single-arm study enrolling 1014 transcatheter aortic valve replacement (TAVR) patients. The objective of this analysis is to assess the impact of cerebral embolic protection (CEP) devices and prosthetic valve repositioning on the risk of neurologic complications in patients treated with the fully repositionable Lotus Valve in the RESPOND postmarket study. Valve repositioning and CEP use were at the operators' discretion. Stroke events were adjudicated by an independent medical reviewer. This analysis assessed the baseline differences among patients according to CEP use and valve repositioning and evaluated the neurological complications at 72 hours after TAVR, hospital discharge, and 30-day follow-up. A multivariate analysis was performed to identify the potential predictors of stroke. Of the 996 patients implanted with the Lotus Valve (mean age: 80.8 years, 50.8% female, STS score 6.0 ± 6.9), 92 cases (9.2%) used CEP. The overall rate of acute stroke/transient ischemic attack (TIA) was 3.0% at 72 hours after TAVR. The 72-hour stroke/TIA rate was 1.1% in patients who had CEP and 3.2% in those who did not. Use of CEP was associated with a 2.1% absolute reduction in the risk of acute neurological events (relative risk reduction: 65.6%), although the difference was not statistically significant (p=0.51). Repositioning of the Lotus Valve occurred in 313/996 procedures (31.4%). The 72-hour rate of stroke/TIA was similar in patients who had valve repositioning (2.9%) compared with those who did not (3.1%; p=0.86). The selective use of a CEP device in the RESPOND study was associated with a nonsignificantly lower risk for stroke within 72 hours. The use of the repositioning feature of the Lotus Valve did not increase the stroke risk.

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.

Impact of Perioperative Stroke on Midterm Outcomes After Transcatheter Aortic Valve Replacement

BACKGROUND

Transcatheter aortic valve replacement (TAVR) has evolved as an alternative therapy to open aortic valve replacement in most patients with aortic stenosis. Stroke associated with TAVR can be a devastating complication in the short term; however, little is known regarding midterm outcomes.

METHODS

All patients undergoing TAVR at the University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania from 2011 to 2018 were included. Modified Rankin Scale values as a measurement of stroke-related disability were extracted for patients who had neurologic deficits.

RESULTS

Neurologic events (NEs) developed in 51 (4.3%) of the 1193 patients during the study period (32 [2.7%] had disabling strokes; 19 [1.6%] had nondisabling strokes, including 5 [0.4%] transient ischemic attacks). Patients who had TAVR-related NEs were older (85.8 ± 4.2 years vs 81.5 ± 7.9 years; P < .001) and predominantly female (68.6% vs 31.4%; P = .007), but they were comparable in terms of The Society of Thoracic Surgeons predicted mortality score and vascular access. Patients with NEs had increased short term and midterm mortality (15.7% vs 2.6%, 29.4% vs 13.9%, and 47.1% vs 35.7% at 30 days, 1 year, and 3 years, respectively). Severity of disability, determined by the modified Rankin Scale, was a risk factor for 30-day mortality (HR, 5.8; P = .003), 1-year mortality (HR, 2.1; P < .001) and 3-year mortality (HR, 1.8; P < .001). Predictors of TAVR NEs were older age (odds ratio [OR] per year of age, 1.11; P = .001), low body surface area (OR per m², 0.22; P = .050), procedural duration (OR per minute, 1.01; P = .024), and administration of blood products (OR, 3.23; P = .002).

CONCLUSIONS

Stroke increases short-term and midterm mortality after TAVR. Risk prediction for neurologic events in TAVR could aid the framework for patient selection and further improve outcomes.

Transcatheter aortic valve implantation: a new standard of care

Aortic stenosis is the most common valvular lesion requiring intervention and with an ageing population, its burden is likely to increase. Increasing comorbidity and a desire for less invasive treatment strategies has facilitated the expansion of percutaneous aortic valve therapies. Robust clinical trial data are now available to support the role of transcatheter aortic valve implantation (TAVI) in patients of prohibitive, high and now intermediate surgical risk. The introduction of a Medicare Benefits Schedule reimbursement is likely to see TAVI use grow exponentially in Australia over the next 5 years. Clinical trials evaluating low risk patients may be the final frontier to see TAVI become the standard of care for most patients with severe aortic stenosis.

Preventing brain embolism by using a modified isolation technique in transcatheter aortic valve implantation for a patient with shaggy and porcelain aorta

Transcatheter aortic valve implantation (TAVI) has become a useful and effective treatment for surgical high-risk patients with severe aortic valve stenosis (AS). Stroke is one of the most frequent complications associated with TAVI. Shaggy and porcelain aortas are a risk factor for procedure-related strokes. Preventing brain embolism is one of the most important goals in patients with diseased aortas. We present a case where we performed TAVI in an 89-year-old man with severe AS, a shaggy aorta, a porcelain aorta, and congestive heart failure. TAVI via a transfemoral approach was performed using a modified isolation technique with cannulation from bilateral axillary arteries and cardiopulmonary bypass to prevent brain embolism. The catheter-delivered embolic protection device is necessary to pass the diseased aorta, but the modified isolation technique can be used without any contact with the shaggy aorta. Embolism did not occur, and his heart failure improved immediately. <Learning objective: Transcatheter aortic valve implantation (TAVI) is a therapeutic option for patients with severe aortic stenosis considered to be at high risk for aortic valve replacement. Cerebral embolism is the most frequent complication of TAVI. A shaggy or porcelain aorta is associated with a high risk of stroke during TAVI. We report a case of TAVI in a shaggy and porcelain aorta and prevention of cerebral embolism by adopting a modified isolation technique without using conventional protection devices.>.

Future Directions. Transcatheter Aortic Valve Implantation for Low-risk Patients: Inevitable Evolution or a Step Too Far?

Transcatheter aortic valve replacement has become the treatment of choice for inoperable and high-risk patients with symptomatic aortic stenosis, and is becoming more and more common as the first choice for intermediate-risk patients as well. The next step in this evolution would be the expansion of treatment indications to low-risk patients. Successful treatment of this patient population will require setting new standards in terms of clinical outcomes and cost effectiveness. In this review, we present the main challenges that need to be addressed before transcatheter aortic valve replacement can be applied as a standard treatment for low-risk patients.

Cerebral Embolic Protection in TAVI: Friend or Foe

Cerebrovascular accidents including stroke or transient ischaemic attack are one of the most feared complications after transcatheter aortic valve implantation. Transcatheter aortic valve implantation procedures have been consistently associated with silent ischaemic cerebral embolism as assessed by diffusion-weighted MRI. To reduce the risk of cerebrovascular accidents and silent emboli, cerebral embolic protection devices were developed with the aim of preventing procedural debris reaching the cerebral vasculature. The authors summarise the available data regarding cerebral embolic protection devices and its clinical significance.