Carotid Artery Stenting During Endovascular Treatment of Acute Stroke

Rationale: Approximately 20% of the patients with acute ischemic stroke due to an intracranial large vessel occlusion (LVO) has a high-grade stenosis in the ipsilateral cervical carotid artery. It is uncertain whether immediate carotid artery stenting (CAS) of a cervical carotid artery stenosis during endovascular thrombectomy (EVT) is beneficial. Immediate CAS could improve cerebral perfusion and prevent recurrent ischemic stroke but could also increase the chance of intracranial hemorrhagic complications due to hyperperfusion syndrome or to the required antiplatelet treatment to prevent stent occlusion. Moreover, some patients end up with a severe disabling stroke after EVT. In these patients carotid revascularization by carotid endarterectomy (CEA) or CAS would usually not be performed but these patients would be treated by medical management only.

Objective: to assess the safety and efficacy of immediate cervical CAS during EVT in patients with acute ischemic stroke due to LVO with a high-grade stenosis \>50% or occlusion of the ipsilateral cervical carotid artery.

Study design: prospective randomized open label controlled trial comparing immediate CAS during EVT versus EVT with deferred treatment of the cervical carotid artery lesion (deferred CAS/CEA or medical management alone). Outcome assessment will be blinded for treatment allocation.

Background and study aims A stroke is a serious life-threatening medical condition that happens when the blood supply to part of the brain is cut off. Approximately 1 in 5 patients suffering stroke have a narrowed carotid artery. It is not yet known if early treatment to insert a tube (stent) into the narrowed artery to hold it open and prevent future stroke is worth the difficulties associated with such treatment.

Who can participate? Patients with acute ischemic stroke with a CT-angiography-proven intracranial LVO in the anterior circulation (ICA, A1, M1 or M2) as well as an ipsilateral cervical carotid artery tandem lesion of presumed atherosclerotic origin with a stenosis \>50% or an ipsilateral acute proximal internal carotid artery occlusion who are treated with EVT according to the guidelines.

What does the study involve? Patients will be randomly allocated to receive either a carotid artery stent immediately after suffering a stroke, or to treatment as usual.

What are the possible benefits and risks of participating? Nature and extent of the burden and risks associated with participation, benefit and group relatedness: All patients are being treated with EVT according to the local guidelines. The patients allocated to the intervention group will undergo CAS during EVT, which carries a risk of cerebral hyperperfusion syndrome and subsequent intracerebral hemorrhage. The potential benefits of immediate CAS during thrombectomy include: an improvement of cerebral blood flow during and after EVT. A second benefit is a lower risk of recurrent stroke in the first 14 days compared to the deferred treatment strategy. A third benefit of immediate CAS is that the patient does not need a second invasive treatment (carotid revascularization surgery (CEA or CAS) during the rehabilitation period which again carries some risk of complications. At last, the immediate CAS approach is likely to reduce health care costs.

Where is the study run from? The study will be coordinated by the University Medical Center Groningen in the Netherlands and by the University Hospital Leuven in Belgium. 26 centres (9 in Belgium and 17 in the Netherlands) will participate.

When is the study starting and how long is it expected to run for? November 2022 to November 2026

Who is funding the study? The study is part of the COllaboration of New TReatments of Acute STroke (CONTRAST) consortium (www.contrast-consortium.nl).

The study is funded by the BeNeFIT funding members (ZonMw/KCE) (the Netherlands)

Eligibility Criteria:
Inclusion Criteria:

1. Acute ischemic stroke due to proximal intracranial occlusion in the anterior circulation (intracranial ICA, M1, proximal M2) on the CT angiography
2. Stenosis \>50% according to the NASCET criteria16 or initial occlusion of the ipsilateral cervical carotid artery of presumed atherosclerotic origin on baseline CT angiography
3. Eligible for EVT according to the guidelines: EVT within 6 hours of onset or EVT between 6-24 hours after onset based on perfusion CT imaging selection (conform current guidelines)
4. Baseline National Institute of Health Stroke Scale (NIHSS) score ≥2
5. Age \>18 years
6. Written informed consent (deferred consent)

Exclusion Criteria:

1. Any intracranial hemorrhage
2. Cervical carotid artery stenosis or occlusion with other causes than presumed atherosclerosis (e.g. carotid artery dissection, floating thrombus, carotid web)
3. Any exclusion criterion for EVT according to the guidelines
4. Pre stroke disability (defined as a modified Rankin Scale score \>2)
5. Recent gastro-intestinal or urinary tract hemorrhage (\<6 weeks)
6. Recent severe head trauma (\<6 weeks)
7. Recent infarction on baseline brain CT in the same vascular territory (\<6 weeks)
8. Known allergy to aspirin and/or clopidogrel
9. Pregnancy