Immediate Management of Large Vessel Occlusion Stroke

Diagnostic Approach

The Canadian Stroke Best Practice guidelines recommend immediate brain imaging with both non-contrast CT and CT angiography without delay for patients potentially eligible for endovascular thrombectomy within 6 hours, which is Level A evidence 1, 2, 3
Complete non-contrast CT should be performed to exclude hemorrhage, followed by immediate CTA (arch-to-vertex) to identify large vessel occlusions 1, 2, 3

IV alteplase should be initiated immediately if the patient meets eligibility criteria (within 4.5 hours, no contraindications), even when LVO is suspected and mechanical thrombectomy is being considered, with a target door-to-needle time of less than 60 minutes (ideally 30 minutes) 4, 5
CTA should be obtained without delay to identify the LVO and plan for EVT, as it provides essential information for treatment decisions, including vessel tortuosity and collateral status 1, 2, 3, 6
Mechanical thrombectomy remains highly effective for patients with LVO, and should be performed without waiting to see if alteplase works, as any delay worsens outcomes 4, 5

Within 0-4.5 hours, IV alteplase is strongly recommended (Level A evidence), and CTA should be obtained simultaneously to identify LVO 1, 2, 3, 4, 5
Within 4.5-6 hours, CTA is essential to identify LVO candidates for EVT, and mechanical thrombectomy remains highly effective 1, 2, 3, 4, 5
Beyond 6 hours (6-24 hours), advanced imaging (CT perfusion or MRI-DWI) is required to assess ischemic core and penumbra, and patients with small core and large penumbra or severe clinical deficit remain EVT candidates 1, 2, 3, 4, 5

Primary stroke centers without CTA capability should complete non-contrast CT, administer IV alteplase if appropriate, and then rapidly transfer the patient to a comprehensive stroke center for CTA and potential EVT, without delaying transfer waiting to see if alteplase works 1, 2, 3
Patients on anticoagulation, such as warfarin with INR ≤1.7, may receive IV alteplase, while those on direct oral anticoagulants (DOACs) should not routinely receive alteplase, but EVT should still be considered 4