Optical Coherence Tomography Guided Antithrombotic Treatment After Endovascular Thrombectomy of the Posterior Circulation

Study Overview
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Brief Summary
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Evidence regarding the role of early (<24 hours) antithrombotics post-revascularization with either intravenous thrombolysis (IVT), endovascular thrombectomy (EVT), or a combination of both remains scarce. In 2018 the American Heart Association/American Stroke Association changed their recommendation, stating that the risk of antithrombotic therapy within the first 24 hours after treatment with IVT (with or without EVT) is uncertain. This was changed after data emerged that early antithrombotics may be safe and may improve outcomes in select patients undergoing EVT. Recently the investigators showed for the first time that significant residual basilar thrombus can exist after EVT despite complete angiographic revascularization using endovascular optical coherence tomography imaging. This residual thrombus could cause ongoing function-limiting strokes with occlusion of vital basilar perforators after EVT. Therefore, the investigators propose a prospective,non-randomized safety study to evaluate optical coherence tomography guided antithrombotic management for patients with confirmed residual thrombus after EVT for basilar occlusion.

Official Title
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Optical Coherence Tomography Guided Antithrombotic Treatment After Endovascular Thrombectomy of the Posterior Circulation

Conditions
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Stroke of Basilar Artery, Optical Coherence Tomography, Antithrombotics, Endovascular Thrombectomy

Intervention / Treatment
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* Drug: Unfractionated heparin
* Drug: Acetylsalicylic Acid (ASA)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - All patients deemed candidates for endovascular thrombectomy(EVT) for basilar artery occlusion. As no robust guidelines exist for the role of EVT in patients with acute basilar artery occlusion, the decision for EVT is made by a team of stroke neurologist and neuro-interventionalist at our regional stroke center. Exclusion Criteria: High-density lesion consistent with hemorrhage of any degree. Significant established infarct size. Contraindication to receiving post-revascularization antithrombotics for any reason (history of major hemorrhage in the past six months, hereditary or acquired bleeding diathesis, major surgery within last three months, platelets <100 X 109 /L, coagulation factor deficiency, already on anticoagulant that would not allow administration of UFH) Informed consent is not or cannot be obtained. Females of childbearing potential who are known to be pregnant and/or lactating or who have positive pregnancy tests on admission. Other serious, advanced, or terminal illness. Patients who require hemodialysis or peritoneal dialysis. Uncontrolled hypertension defined as systolic blood pressure>185 mm Hg or diastolic blood pressure>110mm Hg that cannot be controlled except with continuous parenteral antihypertensive medication

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Optical coherence tomography confirmed residual thrombus<br>Early antithrombotics | Drug: Unfractionated heparin<br>* Intravenous unfractionated heparin (UFH) infusion within 6 hours of EVT with target activated partial thromboplastin time (aPTT) 64-86 Anticoagulation to continue for minimum of 48 hours (can be maintained on UFH aPTT 64-86 or transitioned to low-molecular weight heparin (LMWH) Enoxaparin 1mg/kg)<br>Drug: Acetylsalicylic Acid (ASA)<br>* Acetylsalicylic Acid (ASA) 325mg PO/PR/NG loading dose < 2 hours of EVT completion ASA 81mg PO OD maintenance dose<br>|
| No Intervention: Optical coherence tomography confirmed no residual thrombus<br>Best medical management | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Favorable outcome | Favorable outcome at day 90 defined as a modified Rankin Score (mRS - functional scale) of 0-3. | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptomatic Intracranial Hemorrhage |  | 24 hours CT imaging ± 8 hours. | 
| Incidence of residual thrombus | Fraction of patients with residual thrombus after endovascular thrombectomy as observed with optical coherence tomography | Immediately after endovascular thrombectomy | 
| Excellent Outcome | Excellent outcome at day 90 defined as a modified Rankin Score (mRS - functional scale) of 0-2. | 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Basilar, Stroke, Thrombus, Optical Coherence Tomography