Bilateral carotid filter implants to prevent repeat large-artery embolic strokes in people with atrial fibrillation

Carotid Implants for PreveNtion of STrokE ReCurrEnce From Large Vessel Occlusion in Atrial Fibrillation Patients Treated With Oral Anticoagulation

This trial will try whether placing bilateral carotid filter implants in addition to standard oral blood thinners reduces repeat large-artery ischemic strokes in people with atrial fibrillation who had a recent stroke.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 2000 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Javelin Medical (industry)
• Drugs / interventions: radiation
• Locations: 1 site (Hamilton, Canada)
• Trial ID: NCT05723926 on ClinicalTrials.gov

What this trial studies

This randomized study compares standard oral anticoagulation alone versus oral anticoagulation plus bilateral Vine carotid filter implants in patients with atrial fibrillation who had an ischemic stroke within the past year. The filters are placed in both common carotid arteries and have been shown in laboratory testing to capture emboli ≥1.4 mm and some smaller particles. Investigators expect the implants to prevent most emboli from reaching the anterior circulation, where the majority of large-vessel occlusions occur, while recognizing the posterior circulation will not be protected. Participants must meet carotid diameter and access criteria on imaging and be able to take single antiplatelet therapy alongside anticoagulation for a limited period.

Who should consider this trial

Good fit: Ideal candidates are people with documented atrial fibrillation who had a recent non-hemorrhagic ischemic stroke within the specified enrollment window, plan to use a VKA or DOAC for the trial, can take single antiplatelet therapy, and have carotid artery anatomy that fits the device.

Not a fit: Patients with posterior-circulation strokes, unsuitable carotid anatomy, inability to tolerate antiplatelet therapy, high bleeding risk, or hemorrhagic stroke history are unlikely to benefit from the carotid filters.

Why it matters

Potential benefit: If successful, the implant could substantially reduce disabling anterior large-vessel embolic strokes on top of what anticoagulation alone provides.

How similar studies have performed: These carotid filters have demonstrated embolus capture in vitro, but clinical evidence of stroke reduction with extracranial carotid embolic filters is limited and this application is relatively novel.

Eligibility criteria

Inclusion Criteria:

1. Documented history of clinical AF
2. History of ischemic (i.e. non-hemorrhagic) stroke including symptoms of stroke resolving within 24 hours with positive neuro-imaging, meeting one of the following criteria:

   Group 1: Patient was on OAC at time of index stroke, with index stroke occurring \< 6 week from enrollment Group 2: Patient was not on OAC at time of stroke, with index stroke occurring \< 6 weeks from enrollment Group 3: Patient was on OAC at time of index stroke, with index stroke occurring 6 to 52 weeks from enrollment
3. Planned use of a Vitamin K antagonist (VKA) or a direct oral anticoagulant (DOAC) for the duration of the trial
4. Patient able to tolerate single antiplatelet therapy in addition to oral anticoagulation for 6 months, in the opinion of the investigator
5. Bilateral ultrasound or angiogram demonstrating all of the following:

   1. Inner common carotid artery diameter range: ≥5.3 mm and ≤8.8 mm
   2. Accessibility: up to 40 mm from skin to common carotid artery center
   3. Implantation segment free of any atherosclerotic disease
   4. Absence of carotid dissection or pre-existing stent(s) in common carotid artery
   5. Absence of ≥50% stenosis of the internal carotid arteries as seen on ultrasound or angiography (CTA, MRA or DSA)

   i. For ultrasound, calculate the percentage of carotid stenosis using the Society of Radiologists in Ultrasound Consensus Criteria for Carotid Stenosis, where ≥50% stenosis is defined by internal carotid artery peak systolic velocity of ≥125 cm/sec, internal/common carotid peak systolic velocity ratio of 2 or more and end diastolic velocity of ≥40 cm/sec, or evidence of near occlusion.

   ii. For angiography, calculate the percentage of carotid stenosis using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria (\[D - N\]/D x 100, where N is the luminal diameter at the site of maximal narrowing and D is the diameter of normal distal internal carotid artery beyond the bulb where the artery walls are parallel.
6. Provision of informed consent

Exclusion Criteria:

1. Contraindication to oral anticoagulation (e.g. history of intracranial hemorrhage, known hereditary or acquired coagulation disorders, or recurrent major bleeding)
2. Contraindication to additional single antiplatelet therapy for 6 months from randomization
3. Previously documented 50% or greater stenosis, or high-risk plaque in the opinion of the investigator, of the common carotid, internal carotid, subclavian, vertebral, or intracranial arteries that has not been treated with a revascularization procedure (i.e. stent or angioplasty)
4. Visualized active (acute/subacute) cervical or intracranial arterial thrombus (i.e. free-floating) on computed tomography (CT), magnetic resonance (MR), or digital subtraction (DS) angiography that is at risk of causing additional stroke/brain injury
5. Previously documented aneurysm of the internal carotid artery or its branches (i.e. ophthalmic, posterior communicating, anterior choroidal, anterior cerebral and middle cerebral arteries) that is 6 mm or greater in diameter.
6. Prior surgery or radiation of the neck at the implantation segment
7. Pre-existing percutaneous left atrial appendage occlusion device that was implanted after most recent ischemic stroke
8. Planned left atrial appendage occlusion procedure
9. Female who is pregnant or non-postmenopausal female who is not willing to use an effective method of birth control during duration of the trial
10. Overt systemic infection
11. Known sensitivity to nickel or titanium metals, or their alloys
12. Active participation in another investigational drug or device treatment trial
13. Any other condition that in the opinion of the investigator may adversely affect the safety of the patient or would limit the patient's ability to complete the trial

Where this trial is running

Hamilton, Canada

• Hamilton General Hospital — Hamilton, Canada, Canada (RECRUITING)

Study contacts

• Principal investigator: Stuart Connolly, MD, FRCPC — Population Health Research Institute, McMaster University
• Study coordinator: Sagit Broder, MSc

Conditions: Atrial Fibrillation, Oral Anticoagulation, Stroke, Implant, Filter, Ischemic stroke, NOAC, LVO