Optical Coherence Tomography-Assisted Strategy for Interventional Management of Symptomatic Carotid Stenosis (OASIS-C)

Carotid artery stenosis is a major cause of ischemic stroke, and its prevalence has increased by 59.1% over 20 years. Among patients with symptomatic severe carotid stenosis receiving medical therapy, the 2-year ipsilateral stroke rate reaches 26%. Although endovascular therapy is considered comparable to carotid endarterectomy in reducing stroke risk, the CAVATAS study showed that carotid artery stenting and carotid balloon angioplasty were associated with 1-year restenosis rates of 13.1% and 25.3%, respectively, and carried a higher risk of stroke. Plaque characteristics may be important determinants of arterial restenosis and stroke events after endovascular treatment. Optical coherence tomography (OCT), currently the highest-resolution intravascular imaging technique, can help characterize plaques to guide the strategy of endovascular treatment for carotid stenosis, reducing restenosis and stroke event rates, and avoiding unnecessary stent placement. All enrolled patients underwent endovascular treatment according to a prespecified OCT-guided strategy. The purpose of this study is to evaluate the safety, feasibility, and clinical value of OCT-guided endovascular therapy in patients with symptomatic carotid stenosis through a multicenter, prospective, exploratory trial.

• OCT guided endovascular treatment (Procedure): OCT guides carotid balloon angioplasty and/or stenting of the target artery.

Primary outcomes

• Any stroke or death from enrollment to 30 days after endovascular treatment of the qualifying artery, or ipsilateral ischemic stroke or ischemic driven qualifying artery revascularization during the remaining follow-up period up to 6 months [6 months]: This outcome includes ischemic/hemorrhagic stroke or all-cause death from enrollment to 30 days after endovascular treatment of the qualifying artery, or ipsilateral ischemic stroke or ischemic driven qualifying artery revascularization during the remaining follow-up period up to 6 months.

Secondary outcomes

• Any stroke or death from enrollment to 30 days after endovascular treatment of the qualifying artery [30 days]: Ischemic/hemorrhagic stroke or all-cause death from enrollment to 30 days after endovascular treatment of the qualifying artery.
• Any ipsilateral stroke or death within 3 months after enrollment [3 months]: Ipsilateral ischemic/hemorrhagic stroke or all-cause death within 3 months after enrollment.
• Any contralateral stroke within 3 months after enrollment [3 months]: Contralateral ischemic/hemorrhagic stroke within 3 months after enrollment.
• Neurological improvement assessed by mRS at 3 months [3 months]: Modified Rankin Scale (mRS score) ranged from 0 to 6 is used to measure the recovery of neurological function in patients after stroke. Score 0 means completely no symptom. Score 6 means death. Higher values represent a worse outcome.
• Any ipsilateral stroke or death within 6 months after enrollment [6 months]: Ipsilateral ischemic/hemorrhagic stroke or all-cause death within 6 months after enrollment.
• Any contralateral stroke within 6 months after enrollment [6 months]: Contralateral ischemic/hemorrhagic stroke within 6 months after enrollment.
• Ischemic driven qualifying artery revascularization within 6 months after enrollment [6 months]: Ischemic driven qualifying artery revascularization within 6 months after enrollment.
• Neurological improvement assessed by mRS at 6 months [6 months]: Modified Rankin Scale (mRS score) ranged from 0 to 6 is used to measure the recovery of neurological function in patients after stroke. Score 0 means completely no symptom. Score 6 means death. Higher values represent a worse outcome.
• Restenosis of the qualifying artery within 6 months [6 months]: Restenosis is defined as rate of stenosis >70% or increased by 30% based on following-up neurovascular imaging.
• Combined vascular events within 6 months after enrollment [6 months]: Combined vascular events include stroke, myocardial infarction and vascular death. Myocardial infarction occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen; vascular death means the death is due to vessel rupture or clot.
• Quality of life assessment (EuroQol-5-Dimensions Scale [EQ-5D] questionnaire) at 6 months after enrollment [6 months]: Quality of life evaluated by EuroQol-5-Dimensions Scale (EQ-5D) questionnaire at the 6 months follow-up. EQ-5D descriptive system covers five dimensions including mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has three response levels (no problem, some problems, and severe problems). The EQ-5D descriptive system generates 243 health states, each of which was assigned a utility. score ranging from -0.59 to 1.00 (full health).
• Any ipsilateral stroke or death within 12 months after enrollment [12 months]: Ipsilateral ischemic/hemorrhagic stroke or all-cause death within 12 months after enrollment.
• Any contralateral stroke within 12 months after enrollment [12 months]: Contralateral ischemic/hemorrhagic stroke within 12 months after enrollment.
• Ischemic driven qualifying artery revascularization within 12 months after enrollment [12 months]: Ischemic driven qualifying artery revascularization within 12 months after enrollment.
• Neurological improvement assessed by mRS at 12 months [12 months]: Modified Rankin Scale (mRS score) ranged from 0 to 6 is used to measure the recovery of neurological function in patients after stroke. Score 0 means completely no symptom. Score 6 means death. Higher values represent a worse outcome.
• Restenosis of the qualifying artery within 12 months [12 months]: Restenosis is defined as rate of stenosis >70% or increased by 30% based on following-up neurovascular imaging.
• Combined vascular events within 12 months after enrollment [12 months]: Combined vascular events include stroke, myocardial infarction and vascular death. Myocardial infarction occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen; vascular death means the death is due to vessel rupture or clot.
• Any ipsilateral stroke or death within 24 months after enrollment [24 months]: Ipsilateral ischemic/hemorrhagic stroke or all-cause death within 24 months after enrollment.
• Any contralateral stroke within 24 months after enrollment [24 months]: Contralateral ischemic/hemorrhagic stroke within 24 months after enrollment.
• Ischemic driven qualifying artery revascularization within 24 months after enrollment [24 months]: Ischemic driven qualifying artery revascularization within 24 months after enrollment.
• Neurological improvement assessed by mRS at 24 months [24 months]: Modified Rankin Scale (mRS score) ranged from 0 to 6 is used to measure the recovery of neurological function in patients after stroke. Score 0 means completely no symptom. Score 6 means death. Higher values represent a worse outcome.
• Restenosis of the qualifying artery within 24 months [24 months]: Restenosis is defined as rate of stenosis >70% or increased by 30% based on following-up neurovascular imaging.
• Combined vascular events within 24 months after enrollment [24 months]: Combined vascular events include stroke, myocardial infarction and vascular death. Myocardial infarction occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen; vascular death means the death is due to vessel rupture or clot.
• Any ipsilateral stroke or death within 36 months after enrollment [36 months]: Ipsilateral ischemic/hemorrhagic stroke or all-cause death within 36 months after enrollment.
• Any contralateral stroke within 36 months after enrollment [36 months]: Contralateral ischemic/hemorrhagic stroke within 36 months after enrollment.
• Ischemic driven qualifying artery revascularization within 36 months after enrollment [36 months]: Ischemic driven qualifying artery revascularization within 36 months after enrollment.
• Neurological improvement assessed by mRS at 36 months [36 months]: Modified Rankin Scale (mRS score) ranged from 0 to 6 is used to measure the recovery of neurological function in patients after stroke. Score 0 means completely no symptom. Score 6 means death. Higher values represent a worse outcome.
• Restenosis of the qualifying artery within 36 months [36 months]: Restenosis is defined as rate of stenosis >70% or increased by 30% based on following-up neurovascular imaging.
• Combined vascular events within 36 months after enrollment [36 months]: Combined vascular events include stroke, myocardial infarction and vascular death. Myocardial infarction occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen; vascular death means the death is due to vessel rupture or clot.

Sex: All, ages: 20 Years to 80 Years

Inclusion Criteria:

1. Age 20-80 years old.
2. Primary or recurrent symptomatic extracranial carotid artery stenosis (a recent TIA\[<180 days\] or ischemic stroke \[14-180 days\] before enrollment attributed to 50-99% stenosis of extracranial carotid artery) receiving treatment with at least one antithrombotic drug and/or standard medical management of vascular risk factors.
3. Diagnosed by DSA: an extracranial carotid artery stenosis (50-99% according to NASCET method) with lesion length ≤ 10mm, diameter ≥ 1.5mm, and normal distal artery. (Regarding the curvature and angle of the lesion, whether the patient is enrolled per the investigator's determination based on the patient's situation ).
4. Informed consent signed.

Exclusion Criteria:

1. Acute ischemic stroke onset within 14 days before enrollment.
2. Neurological deficits worsen within 24 hours before enrollment.
3. Baseline modified Rankin Scale ≥ 3.
4. Thrombolytic therapy within 24 hours before enrollment.
5. Previous ipsilateral endovascular treatment.
6. Intracranial hemorrhage within the past 3 months.
7. Any major surgery, major trauma, revascularization procedure, or acute coronary syndrome within 1 month before enrollment.
8. Major (non-carotid) surgery/procedures planned within 3 months after enrollment.
9. Gastrointestinal hemorrhage within 1 month prior to enrollment.
10. Allergic to heparin, aspirin, clopidogrel, contrast agents, anesthetics, and balloon components.
11. Platelet count < 100,000/microliter or history of heparin-induced thrombocytopenia.
12. Severe dysfunction of liver (ALT > three-fold higher than the upper limit of normal value or AST > three-fold higher than the upper limit of normal value) or kidney (serum creatinine > two-fold higher than the upper limit of normal value).
13. Non-atherosclerotic carotid stenosis (dissection, fibromuscular dysplasia, or stenosis following radiation therapy).
14. Intracranial arteries, target artery's supplying artery or contralateral carotid artery with 50-99% stenosis.
15. Coexistent with Intracranial tumors, aneurysms or arteriovenous malformations.
16. Tortuous vascular approach that cannot be stabilized to obtain vascular access.
17. Pregnant and lactating women.
18. Expected survival expectation is less than < 6 months.

• Zhongrong Miao, MD, Principal investigator, Beijing Tiantan Hospital
• Ning Ma, MD, Principal investigator, Beijing Tiantan Hospital