Histopathology of embolic debris captured during transcatheter aortic valve replacement

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.

Predictors of Early Stroke or Death in Patients Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND/OBJECTIVE

While postoperative stroke is a known complication of Transcatheter Aortic Valve Implantation (TAVI), predictors of early stroke occurrence have not been specifically reviewed. The objective of this study was to estimate the predictors and incidence of stroke during the first 30 days post-TAVI.

METHODS

A cohort of 506 consecutive patients having undergone TAVI between January 2017 and June 2019 was extracted from a prospective database. Preoperative, intraoperative and postoperative characteristics were analyzed by univariate analysis followed by logistic regression to find predictors of the occurrence of stroke or death within the first 30 days after the procedure.

RESULTS

Incidence of stroke within 30 days post-TAVI was 4.9%, [CI 95% 3.3-7.2], i.e., 25 strokes. Four out of the 25 patients (16%) with a stroke died within 30 days post-TAVI. After logistic regression analysis, the predictors of early stroke related to TAVI were: CHA2Ds2VASc score ≥ 5 (odds ratio [OR] 2.62; 95% CI: 1.06-6.49; p = .037), supra-aortic access vs. femoral access (OR: 9.00, 95%CI: 2.95-27.44; p = .001) and introduction post-TAVI of a single vs. two or three antithrombotic agents (OR: 5.13; CI 95%: 1.99 to 13.19; p = .001). Over the 30-day period, bleeding occurred in 28 patients (5.5%), in 25 of whom, it was associated with femoral or iliac artery access injury. Anti-thrombotic regimen was not associated with bleeding; two patients out of 48 (4.1%) bled with a single anti-thrombotic regimen vs. 26 patients out of 458 (5.6%) with a dual or triple anti-thrombotic regimen (p = 0.94). The overall 30-day mortality rate was 3.9%, [95% CI 2.5-6.0]. Patients with a single post-TAVI antithrombotic agent (OR: 44.07 [CI 95% 13.45-144.39]; p < .0001) and patients with previous coronary artery bypass surgery or coronary artery stenting (OR: 6.16, [CI 95% 1.99-21.29]; p = .002) were at significantly higher risk of death within the 30-day period.

CONCLUSION

In this large-scale single-center retrospective study, a single post-TAVI antithrombotic regimen independently predicted occurrence of early stroke or death. Dual or triple antithrombotic regimen was not associated with a higher risk of bleeding and should be considered as an option in patients undergoing TAVI.

Transcatheter aortic valve implantation induces transient drop in platelet reactivity

ABSTRACT

Although recent studies described platelet reactivity (PR) changes in days following transcatheter aortic valve implantation (TAVI), precise time course and duration of these changes have not been fully investigated. The aim of this study was to investigate PR pattern during and after TAVI in multiple time points. Study included 40 consecutive patients undergoing TAVI. All patients underwent the procedure on dual antiplatelet therapy. PR was measured in seven time points: before induction of anaesthesia (T1), after heparin administration (T2), 10 minutes after initial valve implantation (T3), at the end of procedure (T4), and on 3rd, 6th and 30th postoperative day (T 5-7). PR was measured using impedance aggregometer using three different platelet aggregation agonists (arachidonic acid in ASPItest, adenosine diphosphate in ADPtest and thrombin receptor activating peptide 6 in TRAPtest). All patients underwent successful TAVI procedure. Mean PR on T1 was 22.9±23.0 U for ASPItest, 40.5±23.7 U for ADPtest and 91.7±32.5 U for TRAPtest. There was no significant difference in PR on T2. On T3, significant reduction of PR in all three tests was observed (ASPI 10.4±11.6 U (p=0.001), ADP 24.2±14.1 U (p<0.001) and TRAP 69.3±26.6 U (p<0.001)). PR nadir for all tests was reached on T5, with subsequent PR incline. PR values in all tests returned to baseline levels on T7. Our results show that successful TAVI procedure induces transient decrease in PR regardless of the platelet activation pathway.

Blood Coagulation Changes With or Without Direct Oral Anticoagulant Therapy Following Transcatheter Aortic Valve Implantation

Thromboembolic events remain clinically unresolved after transcatheter aortic valve implantation (TAVI). The use of direct oral anticoagulant (DOAC) to reduce thrombosis associated with TAVI remains controversial. This study aimed at investigating the periprocedural change in blood coagulation and thrombolysis parameters in 199 patients undergoing transfemoral TAVI. Prothrombin activation fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), soluble fibrin monomer complex (SFMC), and fibrin/fibrinogen degradation product (FDP) levels were measured before and 1 hour after TAVI and 1, 2, and 7 days postoperatively. Of the 199 patients, 49 were treated with DOAC (apixaban in 32, edoxaban in 10, and rivaroxaban in 7). The F1 + 2 and TAT levels immediately increased 1 hour after TAVI and then gradually decreased in both groups. The SFMC level also significantly increased with a peak on day 1. The FDP level gradually increased, peaking on day 2. The values of F1 + 2, TAT, SFMC, and FDP in patients who used DOAC were significantly lower than those who did not use DOAC at 1 hour after TAVI in F1 + 2 (600 [452 to 765] vs 1055 [812 to 1340] pmol/L; p < 0.001), TAT (21.4 [16.2 to 37.0] vs 38.7 [26.4 to 58.7] μg/mL; p < 0.001) and on day 1 in SFMC (18.2 [9.4 to 57.9] vs 113.4 [70.9 to 157.3] μg/mL; p < 0.001) and day 2 in FDP (6.0 [4.7 to 10.0] vs 12.6 [8.2 to 17.4] μg/mL; p < 0.001). Ischemic stroke within 30 days after TAVI occurred in 3 patients (1.5%), who were not treated with DOAC. Coagulation cascade activation was observed after TAVI. DOAC could reduce transient hypercoagulation following TAVI.

Aspirin Alone Versus Dual Antiplatelet Therapy After Transcatheter Aortic Valve Implantation: A Systematic Review and Patient-Level Meta-Analysis

Background In patients undergoing transcatheter aortic valve implantation without an indication for oral anticoagulation, it is unclear whether single or dual antiplatelet therapy (DAPT) is necessary to minimize both the bleeding and thromboembolic risk. In this patient-level meta-analysis, we further investigate the effect of aspirin alone compared with DAPT for preventing both thromboembolic and bleeding events after transcatheter aortic valve implantation. Methods and Results We conducted a systematic review of all available randomized controlled trials comparing aspirin with DAPT. In total, 1086 patients were included across 4 eligible trials. The primary outcomes were the composite of all-cause mortality, major or life-threatening bleeding, stroke or myocardial infarction (first composite outcome), and the same composite excluding bleeding (second composite outcome), both tested at 30 days and 3 months. The first composite outcome occurred significantly less in the aspirin-alone group at 30 days (10.3% versus 14.7%, odds ratio [OR], 0.67; 95% CI, 0.46-0.97, P=0.034) and 3 months (11.0% versus 16.5%, hazard ratio [HR], 0.66; 95% CI, 0.47-0.94, P=0.02), compared with the DAPT group. The second composite outcome occurred in 5.5% and 6.6% at 30 days (OR, 0.83; 95% CI, 0.50-1.38, P=0.47) and in 6.9% and 8.5% at 3 months in the aspirin-alone group compared with the DAPT group (HR, 0.82; 95% CI, 0.52-1.29, P=0.39), respectively. Conclusions In patients without an indication for oral anticoagulation undergoing transcatheter aortic valve implantation, aspirin alone significantly reduced the composite of thromboembolic and bleeding events, and does not increase the composite of thromboembolic events after transcatheter aortic valve implantation, compared with DAPT.

Antithrombotic Therapy for Stroke Patients with Cardiovascular Disease

Prevention of ischemic stroke relies on the use of antithrombotic medications comprising antiplatelet agents and anticoagulation. Stroke risk is particularly high in patients with cardiovascular disease. This review will focus on the role of antithrombotic therapies in the context of different types of cardiovascular disease. We will discuss oral antiplatelet medications and both IV and parental anticoagulants. Different kinds of cardiovascular disease contribute to stroke via distinct pathophysiological mechanisms, and the optimal treatment for each varies accordingly. We will explore the mechanism of stroke and evidence for antithrombotic therapy in the following conditions: atrial fibrillation, prosthetic heart values (mechanical and bioprosthetic), aortic arch atherosclerosis, congestive heart failure (CHF), endocarditis (infective and nonbacterial thrombotic endocarditis), patent foramen ovale (PFO), left ventricular assist devices (LVAD), and extracorporeal membrane oxygenation (ECMO). While robust data exist for antithrombotic use in conditions such as atrial fibrillation, optimal treatment in many situations remains under active investigation.

Cerebral infarction due to dispersal of aortic atheromas detected by transoesophageal echocardiography during transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a rapidly evolving treatment option with an inherent risk of causing cerebral infarctions. The mechanism of cerebral infarction during TAVI mainly involves embolisms from the aortic wall and valve. Transoesophageal echocardiography (TEE) is useful for detecting aortic atheromas. We present the case of a patient in whom the dispersal of aortic atheromas was monitored by TEE during TAVI. This report demonstrates the importance of preoperatively predicting embolisms from aortic atheromas in patients with severe aortic stenosis.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

This study sought to evaluate the feasibility of complete cerebral protection during transcatheter aortic valve replacement (TAVR) with a novel embolic protection device.

BACKGROUND

Evidences and data about new cerebral embolic protection devices are lacking and scarce.

METHODS

A prospective, nonrandomized, multicenter, first-in-man pilot study designed to evaluate the efficacy and safety of cerebral embolic protection utilizing the Emblok embolic protection system (Innovative Cardiovascular Solutions, Grand Rapids, Michigan) during TAVR. The Emblok is a transfemoral aortic filter that provide full coverage of the epiaortic vessels. Brain diffusion-weighted magnetic resonance imaging (DW-MRI) was performed at baseline and 2 to 5 days after TAVR. Primary endpoints were technical success and immediate cerebral embolic burden after TAVR, defined as number and volume of new brain lesions detected with DW-MRI at days 2 to 5 post-TAVR compared with baseline.

RESULTS

A total of 20 subjects were enrolled. The Emblok system was successfully positioned in all the cases. At 30-day follow-up, no major adverse cardiovascular and cerebrovascular events occurred. Nineteen (95%) patients had new ischemic defects at post-procedural DW-MRI. The median number of new lesions per patient was 10.00 (interquartile range [IQR]: 4.75 to 15.25). The total new lesion volume was 199.9 mm³ (IQR: 83.9 to 447.5 mm³) and the mean lesion volume per lesion was 42.5 mm³ (IQR: 21.5 to 75.6 mm³). Histopathologic analysis showed evidence of significant debris in 18 (90%) filters.

CONCLUSIONS

The Emblok embolic protection system appears to be feasible and safe during TAVR. The device was successfully placed and retrieved in all cases and no neurological events were observed. Cerebral total new lesion volume was similar to other trials on cerebral protection during TAVR, thus warranting a larger study. (European Study Evaluating the Emblok Embolic Protection System During TAVR; NCT03130491).

Kidney injury as post-interventional complication of TAVI

Transcatheter aortic valve implantation (TAVI) is an accepted treatment approach of aortic stenosis. In the beginning, this technique was executed in high-risk patients only. Today, intermediate-risk patients are also amenable for TAVI, as long as the transfemoral approach is chosen. Numerous predictors have been identified that could lead to periprocedural complications and are defined by patient co-morbidities as well as being inherent to the technical approach. Although vascular complications and postinterventional paravalvular regurgitation have been minimized over the past years by revised technologies and techniques, there is a prevailing individual risk brought about by the specific pathophysiology of the cardiorenal syndrome.

The history of transcatheter aortic valve implantation: The role and contribution of an early believer and adopter, the Netherlands

This paper describes the history of transcatheter aortic valve implantation (TAVI) from its preclinical phase during which visionary pioneers developed its concept and prototype valves against strong head wind to first application in clinical practice (2002) and the clinical and scientific role of an early believer and adopter, the Netherlands (2005).

Paradoxical Increase of Stroke in Patients with Defect of High Molecular Weight Multimers of the von Willebrand Factors following Transcatheter Aortic Valve Replacement

BACKGROUND

 Stroke is a major cause of disability after transcatheter aortic valve replacement (TAVR) and stroke prediction models and data are crucially needed. Following TAVR, high molecular weight (HMW) multimers defect of von Willebrand factor (VWF) as assessed by closure time of adenosine diphosphate (CT-ADP) value > 180 seconds is an independent predictor of bleeding events. This study sought to identify predictors of ischemic neurological events in patients who underwent TAVR and the specific impact of HMW multimers defect of VWF.

METHODS

 Patients were prospectively enrolled between November 2012 and May 2018 at our institution. The CT-ADP, a point-of-care measure of hemostasis, was assessed the day before and 24 hours after the procedures. The rate of ischemic stroke and transient ischemic attack (TIA) was recorded up to 30 days after the procedures.

RESULTS

 Of 565 TAVR patients, ischemic stroke/TIA was observed in 21 (3.7%) patients within 30 days. Ischemic stroke/TIA was associated with major/life-threatening bleeding complications (MLBCs) (9 [43%] vs. 88 [16%], p = 0.002) and postprocedure CT-ADP > 180 seconds (10 [48%] vs. 116 [21%], p = 0.01). By multivariate analysis, MLBCs (odds ratio [OR]: 3.58; 95% confidence interval [CI]: 1.45-8.84; p = 0.006) and postprocedure CT-ADP > 180 seconds (OR: 3.38; 95% CI: 1.38-8.25; p = 0.008) were evidenced as independent predictors of ischemic stroke/TIA.

CONCLUSION

 MLBCs and CT-ADP > 180 seconds were identified as predictors for ischemic stroke or TIA. The present study suggests that the defects of HMW multimers of the VWFs may contribute not only to bleeding events but also to thrombotic events.

High-intensity transient signals during transcatheter aortic valve implantation assessed by ultrasonic carotid artery blood-flow monitoring: A single center prospective observational study

BACKGROUND

No reports to date have assessed the procedural patterns of high-intensity transient signals (HITS) by monitoring blood flow in cervical arteries. The aim of this study was to examine the sequential distribution of HITS in each procedural phase and predictive factors for HITS during transcatheter aortic valve implantation (TAVI) by monitoring blood flow in the common carotid artery.

METHODS

This prospective observational study included 73 patients who underwent TAVI via the transfemoral artery approach. We continuously evaluated and analyzed HITS from administration of heparin to valve implantation.

RESULTS

HITS peaked during balloon valvuloplasty (BAV), amounting to almost 30% of the total HITS count, followed by valve implantation [BAV 141 (73-186) and valve implantation 86 (64-126), respectively]. In univariate and multivariate analysis, the Agatston score of the aortic valve and low-density lipoprotein were confirmed as independent predictors of HITS frequency with logarithmically converted coefficients of 0.00015 (p < 0.001) and 0.0032 (p = 0.027), respectively.

CONCLUSIONS

These results provide the first evidence that micro-emboli deriving from calcified burden were scattered primally during BAV, followed by valve implantation. The Agatston score may be a predictor for the amount of HITS.

Novel Perspective for Antithrombotic Therapy in TAVI

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While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

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.

Evolution, Predictors, and Neurocognitive Effects of Silent Cerebral Embolism During Transcatheter Aortic Valve Replacement

OBJECTIVES

The aim of this study was to assess the characteristics, predictors, evolution, and neurocognitive effects of silent cerebral ischemic lesions (SCILs).

BACKGROUND

Most patients undergoing transcatheter aortic valve replacement (TAVR) develop SCILs detectable on magnetic resonance imaging (MRI). The natural history and clinical relevance of SCILs are not well established.

METHODS

Cerebral MRI was performed within 7 days before TAVR to assess baseline status and age-related white matter change score. MRI was repeated post-operatively to assess the occurrence, location, number, and dimensions of SCILs. Patients developing SCILs underwent a third MRI examination at 3- to 5-month follow-up. A neurocognitive evaluation was performed before TAVR, at discharge, and at 3-month follow-up.

RESULTS

Of the 117 patients enrolled, 96 underwent post-procedural MRI; SCILs were observed in 76% of patients, distributed in all vascular territories, with a median number of 2 lesions, a median diameter of 4.5 mm, and a median total volume of 140 mm³. Independent predictors of SCIL occurrence were higher baseline age-related white matter change score and the use of self-expanding or mechanically expanded bioprostheses. Among 47 patients who underwent follow-up MRI, only 26.7% of post-procedural SCILs evolved into gliotic scar. SCIL occurrence was associated with a more pronounced transient neurocognitive decline early after TAVR and with lower recovery at follow-up.

CONCLUSIONS

SCILs occur in the vast majority of patients undergoing TAVR and are predicted by more diffuse white matter damage at baseline and by the use of non-balloon-expandable prostheses. Although most SCILs disappear within months, their occurrence has a limited but significant impact on neurocognitive function.

Transcatheter aortic valve replacement with Lotus and Sapien 3 prosthetic valves: a systematic review and meta-analysis

Background

Frequent occurrence of paravalvular leak (PVL) after transcatheter aortic valve replacement (TAVR) was the main concern with early-generation devices and focused technological improvements. Current systematic review and meta-analysis sought to compare outcomes of TAVR for severe native valve stenosis with next-generation devices: Lotus and Sapien 3.

Methods

Electronic databases were screened for studies comparing outcomes of TAVR with Lotus and Sapien 3. In a random-effects meta-analysis, the pooled incidence rates of procedural, clinical and functional outcomes according to VARC-2 definitions were assessed.

Results

Eleven observational studies including 2,836 patients (Lotus N=862 vs. Sapien 3 N=1,974) met inclusion criteria. No differences were observed regarding composite endpoints—device success and early safety. Similarly, 30-day mortality, major vascular complications, acute kidney injury and serious bleeding events were similar with both devices. Lotus valve demonstrated 35% reduction of the risk for mild PVL: risk ratio (RR) 0.65, 95% confidence interval (CI): 0.49–0.85, P=0.002; but there were no statistical differences with regard to moderate/severe PVL (RR 0.56, 95% CI: 0.18–1.77, P=0.320). Lotus valves produced significantly higher mean transaortic gradients: mean difference (MD) 0.88 mmHg, 95% CI, 0.24–1.53 mmHg, P=0.007; however, without translation into higher rate of prosthesis-patient mismatch (RR 1.10, 95% CI: 0.82–1.47, P=0.540). As compared to Sapien 3, Lotus device placement was associated with significantly higher rate of permanent pacemaker implantation (RR 2.30, 95% CI: 1.95–2.71, P<0.00001) and cerebrovascular events (RR 1.76, 95% CI: 1.03–2.99, P=0.040).

Conclusions

Lotus valve, as compared with Sapien 3, was associated with lower risk for PVL but higher risk for permanent pacemaker implantation and cerebrovascular events.

Assessment of Platelet REACtivity After Transcatheter Aortic Valve Replacement: The REAC-TAVI Trial

OBJECTIVES

The REAC-TAVI (Assessment of platelet REACtivity after Transcatheter Aortic Valve Implantation) trial enrolled patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) pre-treated with aspirin + clopidogrel, aimed to compare the efficacy of clopidogrel and ticagrelor in suppressing high platelet reactivity (HPR) after TAVI.

BACKGROUND

Current recommendations support short-term use of aspirin + clopidogrel for patients with severe AS undergoing TAVR despite the lack of compelling evidence.

METHODS

This was a prospective, randomized, multicenter investigation. Platelet reactivity was measured at 6 different time points with the VerifyNow assay (Accriva Diagnostics, San Diego, California). HPR was defined as (P2Y₁₂ reaction units (PRU) ≥208. Patients with HPR before TAVR were randomized to either aspirin + ticagrelor or aspirin + clopidogrel for 3 months. Patients without HPR continued with aspirin + clopidogrel (registry cohort). The primary endpoint was non-HPR status (PRU <208) in ≥70% of patients treated with ticagrelor at 90 days post-TAVR.

RESULTS

A total of 68 patients were included. Of these, 48 (71%) had HPR (PRU 273 ± 09) and were randomized to aspirin + ticagrelor (n = 24, PRU 277 ± 08) or continued with aspirin + clopidogrel (n = 24, PRU 269 ± 49). The remaining 20 patients (29%) without HPR (PRU 133 ± 12) were included in the registry. Overall, platelet reactivity across all the study time points after TAVR was lower in patients randomized to ticagrelor compared with those treated with clopidogrel, including those enrolled in the registry (p < 0.001). The primary endpoint was achieved in 100% of patients with ticagrelor compared with 21% with clopidogrel (p < 0.001). Interestingly, 33% of clopidogrel responder patients at baseline developed HPR status during the first month after TAVR.

CONCLUSIONS

HPR to clopidogrel is present in a considerable number of patients with AS undergoing TAVR. Ticagrelor achieves a better and faster effect, providing sustained suppression of HPR to these patients. (Platelet Reactivity After TAVI: A Multicenter Pilot Study [REAC-TAVI]; NCT02224066).

The Predictors of Peri-Procedural and Sub-Acute Cerebrovascular Events Following TAVR from OCEAN-TAVI Registry

BACKGROUND

Cerebrovascular events (CVEs) are not uncommon complications of transcatheter aortic valve replacement (TAVR). Our study aimed to determine the predictors of peri-procedural and sub-acute CVEs following TAVR.

METHODS

Using the Japanese multicenter registry, we evaluated 1613 patients undergoing TAVR between October-2013 and July-2016. Occurrences of 24-hour and 1- to 30-day CVEs were evaluated to clarify the predictors of CVEs following TAVR.

RESULTS

The mean age was 84.4 years and mean Society of Thoracic Surgeons score was 8.3%. Overall 24-hour and 30-day CVE rates were 1.2% and 2.7%, respectively. A multivariate analysis demonstrated that independent predictor of 24-hour CVEs was index aortic valve area (iAVA) [adjusted OR (adjusted-OR), 0.001; 95% CI, 0.001-0.13; p = .005]. The receiver operator curve derived cut-off value of iAVA for the prediction of 24-hour CVEs was 0.40 cm²/m². In contrast, independent predictors of 1- to 30-day CVEs were paroxysmal atrial fibrillation (PAF; adjusted-OR, 3.35; 95% CI, 1.36-8.27; p = .009) and iAVA after TAVR (adjusted-OR, 0.11; 95% CI, 0.02-0.66; p = .02). Consequently, independent predictors of 30-day CVEs were prior stroke (adjusted-OR, 2.18; 95% CI, 1.07-4.45; p = .03), PAF (adjusted-OR, 2.18; 95% CI, 1.05-4.56; p = .04), and prior coronary artery disease (adjusted-OR, 1.88; 95% CI, 1.01-3.48; p = .05).

CONCLUSIONS

Within 24 h, small iAVA impacted the increased risk of CVEs, whereas PAF and iAVA after TAVR impacted the increased risk of 1- to 30-day CVEs following TAVR. The mechanism of CVEs might differ according to onset.

Debris Heterogeneity Across Different Valve Types Captured by a Cerebral Protection System During Transcatheter Aortic Valve Replacement

OBJECTIVES

This study investigated differences between transcatheter heart valve (THV) types and regarding debris captured by a cerebral embolic protection system (Claret Medical Sentinel, Santa Rosa, California).

BACKGROUND

Differences of THV types and cerebral injury after transcatheter aortic valve replacement (TAVR) are not well understood.

METHODS

A total of 246 patients pooled from 2 prospective studies (SENTINEL [Cerebral Protection in Transcatheter Aortic Valve Replacement] trial, N = 100; SENTINEL-H [Histopathology of Embolic Debris Captured During Transcatheter Aortic Valve Replacement] trial, N = 146) were included in the analysis. Histopathologic assessment and histomorphometric analyses of debris were compared with THV types. Analyses were differentiated by particle size (≥150, ≥500, and ≥1,000 μm), particle count, total particle area, and maximum of largest dimension. Only commercially available THVs were included: 16% Evolut R (EvR), 15% Lotus, 59% SAPIEN 3 (S3), and 10% SAPIEN XT (XT).

RESULTS

Particles were captured in 99% of patients. There was a significantly higher amount of debris related to the vascular bed (valve tissue, arterial wall, calcification) in EvR patients compared with S3 patients; 53% of all patients irrespective of valve type had at least 1 particle ≥1 mm. Larger particles (≥500 and ≥1,000 μm) were significantly more frequent in EvR than XT and S3 patients. Lotus patients with particles ≥1,000 μm were significantly more frequent than in S3 patients. Particle count, total particle area, and maximum of largest dimension were significantly higher in both Lotus and EvR patients compared with S3 and XT.

CONCLUSIONS

Debris was captured in 99% of patients, of whom 53% had at least 1 particle of debris >1 mm. The number and size of particles captured during a procedure in which EvR or Lotus THV was used were higher and larger than with a Sapien THV. Regardless, embolic debris, including large particles, is universal across valve types and provides mechanistic support for the potential benefit of using cerebral embolic protection in all TAVR procedures.

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.

Transcatheter Aortic Valve Replacement with the Lotus Valve: Concept and Current State of the Data

Multiple transcatheter heart valve iterations have created an interesting range of options with which to perform transcatheter aortic valve replacement. The Lotus valve has several attractive features. The ability to eradicate even mild paravalvular leak mirrors the outcomes of surgical aortic valve replacement. New design iterations of the Lotus valve and refined sizing algorithms may help mitigate the need for permanent pacemaker implantation and consolidate its best-in-class results in terms of paravalvular leak. Ongoing trials should help define the safety and efficacy of the Lotus transcatheter heart valve in contemporary practice.

Ischemic Toe Ulceration Due to Foreign Body Embolus From Hydrophilic Polymer-Coated Intravascular Device

Hydrophilic polymer coatings are now widely applied to catheters and other intravascular devices used in neurovascular, cardiovascular, and peripheral vascular procedures. Emboli consisting of these materials have been previously identified in biopsies and autopsies following pulmonary infarction, stroke, gangrene, or death. We report a case involving a nonhealing foot ulcer that appeared following cardiac catheterization, stenting, and automatic implanted cardiac defibrillator (AICD) implantation in a patient without other evidence of significant peripheral artery disease. An 85-year-old woman with chronic atrial fibrillation, aortic valve stenosis, and coronary artery disease underwent coronary stenting and AICD implantation for ventricular tachycardia and syncope. She developed a toe ulcer shortly thereafter, which did not respond to standard treatment. A histological examination following amputation of the toe found amorphous basophilic material in capillaries adjacent to the edge of the ulcer, which was similar to material associated with hydrophilic polymer coatings. Ischemia and infarcts following endovascular procedures should not be presumed to result from thrombus or vascular disease, even if intravascular devices appear intact or properly placed after the procedure. To help establish the incidence of ischemia caused by hydrophilic polymer device coatings, if excision of ischemic or infarcted tissue after endovascular procedures using coated devices becomes necessary, the tissue should be evaluated microscopically. Surgeons should also consider the tolerance of distal organs to infarct or ischemia when selecting coated intravascular devices.

Antithrombotic Therapy in Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has recently emerged as an effective alternative to medical treatment or surgical aortic valve replacement in all symptomatic patients with severe aortic stenosis and high or prohibitive risk and in intermediate risk when transfemoral access is feasible. Patients undergoing TAVR are often at high risk for either bleeding or cerebrovascular complications, or both, so adjuvant antithrombotic therapies are commonly used before, during and after the procedure. Today, there is no clear evidence on the best antithrombotic regimen in this context. In this review, we will try to go through the mechanisms involved in bleeding and embolic complications and we will discuss the current points of antithrombotic treatment in patients during and after TAVR, with or without oral anticoagulation (OAC) indication.

Impact of a Two-Filter Cerebral Embolic Protection Device on the Complexity and Risk of Transcatheter Aortic Valve Replacement

BACKGROUND

There is a growing use of cerebral protection devices in patients undergoing transcatheter aortic valve replacement (TAVR). We aimed to analyze if the use of these devices itself has an impact on the complexity and the risk of TAVR.

METHODS

Between February 2016 and July 2017, 391 patients underwent transfemoral TAVR with Medtronic CoreValve Evolut R (n = 196) or Edwards Sapien 3 (n = 195). In 39 patients, the Claret Sentinel™ embolic protection device (CS-EPD) was used. Prospectively collected data were retrospectively analyzed, comparing fluoroscopy/operation time, amount of contrast used, vascular events, and postprocedural renal function in TAVR patients with (n = 39) and without (n = 352) CS-EPD.

RESULTS

The CS-EPD was placed through the right radial (n = 35) or brachial (n = 4) artery. Procedural success rate defined as correct deployment and retraction of both filters was 94.9%. No device-related vascular complications occurred. TAVR patients with CS-EPD showed a significantly higher total operation time, total fluoroscopy time, and amount of used contrast (85.4 ± 39.3 vs. 64 ± 29.8 minutes, p = 0.002; 20.7 ± 9.3 vs. 13.7 ± 7 minutes, p ≤ 0.001; 133.7 ± 42.6 vs. 109.7 ± 44.5 mL, p = 0.001). Comparing the initial third of patients receiving a CS-EPD with the last third of CS-EPD cases, procedural time had decreased significantly (102.5 ± 34.9 vs. 67 ± 11.9; p = 0.002). There were no differences in postprocedural renal failure (p = 0.80).

CONCLUSION

Our data add evidence that the application of the CS-EPD is not associated with an additional risk for the patient. Although procedural time and amount of contrast are still higher when using the CS-EPD, there were no device-related complications or increased incidence of renal failure.

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.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Neuron-Specific Enolase and Matrix Metalloproteinase 9 Signal Perioperative Silent Brain Infarction During or After Transcatheter Aortic Valve Implantation

Magnetic resonance imaging (MRI) studies have consistently identified a high incidence of silent brain infarction (SBI) after cardiac intervention. The frequent occurrence, objective measurement and clinical sequelae of SBI have seen interest in their detection for both research and clinical purposes. However, MRI is expensive, time-consuming, unsafe in acutely-ill patients, and not always available, limiting its use as a routine screening tool. For this purpose, a blood biomarker of SBI would be the "Holy Grail." By performing targeted profiling of serologic biomarkers this study aimed to assess their potential as screening tools for perioperative SBI. This is a nested case-control study of 20 prospectively recruited patients undergoing transcatheter aortic valve implantation under general anesthesia. Clinical and diffusion-weighted MRI assessments were performed at baseline and on day 3 postprocedure to identify the presence (cases) or absence (controls) of new SBI. Blood was collected at baseline and 24, 48, and 72 hours postprocedure and analyzed for S100 calcium-binding protein B, neuron specific enolase (NSE), matrix metalloproteinase 9 (MMP 9), and glial fibrillary acidic protein. Best-fit polynomial curves using a smoothing model were generated for each biomarker and inferential testing at a predefined 24-hour postprocedure timepoint detected a significant difference for MMP 9 (72,435; SEM: 25,030; p = 0.027). Longitudinal regression revealed a statistically significant case-control difference for both NSE (mean: 10,747; SEM: 3,114) and MMP 9 (63,842; SEM: 16,173). In conclusion, NSE and MMP 9 are present in higher levels following SBI and warrant further investigation for their utility as screening tools.

Cerebral embolic protection systems for transcatheter aortic valve replacement

In the recent years, ischemic brain injury related to embolization after transcatheter aortic valve replacement (TAVR) has received increased attention as new embolic protection strategies emerged to protect the brain. Diverse cerebral protection devices have been developed to reduce cerebral embolization during TAVR. These devices work through various mechanisms and are in different stages of clinical translation. This review provides the evidence-based review of peri-procedural stroke prevention during TAVR and summarizes currently available cerebral embolic protection devices.

Acute ischemic stroke secondary to cardiac embolus of a 'foreign body' material after a redo sternotomy for mitral valve replacement: A case report

Cardiac surgery has been shown to be associated with increased risk of acute ischemic stroke. This report presents a case of a successful mechanical embolectomy procedure to treat a patient for an acute ischemic stroke, which was caused by the cardiac embolization of a 'foreign body' containing debris following a redo sternotomy procedure for mitral valve replacement and tricuspid valve annuloplasty.

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

Cerebrovascular events following transcatheter aortic valve implantation (TAVI) is one of the most devastating complications. Several studies with magnetic resonance or cerebral filters have demonstrated the universal brain embolization after TAVI, in the majority of patients clinically silent. Embolic protection devices (EPD) have been developed as a mechanical barrier to prevent these emboli to reach cerebral vasculature and potentially reduce neurological events. We review the current evidence about EPD in relation to histopathological and cerebral imaging findings and neurological events.

The Role of Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement is the therapy of choice for patients with severe aortic stenosis who have prohibitive or high surgical risk. However, the benefit of TAVR is attenuated by the occurrence of major disabling stroke which is associated with increased mortality and early-reduced quality of life. Despite advances in TAVR technology, stroke remains a serious complication that is associated with significant negative outcomes. The majority of these occur in the acute phase following TAVR where cerebral embolic events are frequent. Cerebral embolic protection devices (CEPD) have been developed to minimize the risk of peri-procedural ischemic stroke during TAVR. CEPD have the potential to reduce intraprocedural burden of new silent ischemic injury. In this review we outline the etiology and incidence of stroke in TAVR population, and systematically review current evidence for cerebral embolic protection devices.

Acute stroke intervention after transcatheter aortic valve replacement

Stroke is a devastating complication in patients undergoing transcatheter aortic valve replacement (TAVR). We sought to determine whether early stroke intervention after TAVR would improve the neurological outcomes. Two patients experienced stroke immediately after TAVR, one treated with mechanical thrombectomy and localized lytic therapy and one treated with systemic lytic therapy. Our limited experience showed that early stroke intervention with either treatment option may reduce the risk of complications and improve neurological outcomes.

Reversed Auxiliary Flow to Reduce Embolism Risk During TAVI: A Computational Simulation and Experimental Study

INTRODUCTION

Endovascular treatments, such as transcatheter aortic valve implantation (TAVI), carry a risk of embolization due to debris dislodgement during various procedural steps. Although embolic filters are already available and marketed, mechanisms underlying cerebral embolism still need to be elucidated in order to further reduce cerebrovascular events.

METHODS

We propose an experimental framework with an in silico duplicate allowing release of particles at the level of the aortic valve and their subsequent capture in the supra-aortic branches, simulating embolization under constant inflow and controlled hemodynamic conditions. The effect of a simple flow modulation, consisting of an auxiliary constant flow via the right subclavian artery (RSA), on the amount of particle entering the brachiocephalic trunk was investigated. Preliminary computational fluid dynamics (CFD) simulations were performed in order to assess the minimum retrograde flow-rate from RSA required to deviate particles.

RESULTS

Our results show that a constant reversed auxiliary flow of 0.5 L/min from the RSA under a constant inflow of 4 L/min from the ascending aorta is able to protect the brachiocephalic trunk from particle embolisms. Both computational and experimental results also demonstrate that the distribution of the bulk flow dictates the distribution of the particles along the aortic branches. This effect has also shown to be independent of release location and flow rate.

CONCLUSIONS

The present study confirms that the integration of in vitro experiments and in silico analyses allows designing and benchmarking novel solutions for cerebral embolic protection during TAVI such as the proposed embo-deviation technique based on an auxiliary retrograde flow from the right subclavian artery.

Antiplatelet therapy in valvular and structural heart disease interventions

Transcatheter interventions for valvular and structural heart diseases are rapidly expanding due to greater operators' experience and development of new generation devices associated with increased procedural safety. They represent the standard strategy for patients with prohibitive risk for open surgery. These procedures are associated with a significant occurrence of both thrombotic and bleeding complications, thus in this setting, even more than in other percutaneous procedures, the balance between thrombotic and bleeding risk is critical. This review describes the current data available on the antithrombotic management of patients undergoing transcatheter aortic valve implantation (TAVI), percutaneous mitral valve repair with the MitraClip system, percutaneous left atrial appendage occlusion and percutaneous patent foramen ovale (PFO)/atrial septal defects (ASD) closure.