The Capillary Index Score Trial

This study is trying to look at how the well-being of the patient following treatment is influenced by peripheral blood supply (collateral flow) to the area lacking primary blood flow due to the clot. Treatment of AIS includes EVT and medical treatment. EVT is typically not offered to patients after 6 hours of the onset of symptoms. The current study is based on the belief that patients can be successfully treated with the EVT up to 8 hours, as long as they have good peripheral blood flow (collateral flow) to the area of tissue blocked of the primary blood supply. The study will evaluate the ability of the capillar index score (CIS) to identify patients who can be successfully treated with EVT. The CIS quantifies blood supply to the ischemic area from peripheral vessels (collateral flow) based on diagnostic cerebral angiogram. Patients are graded on a scale from 0-3, with 0 and 1 considered a poor CIS (pCIS) and 2 and 3 considered a favorable CIS (fCIS). All patients will be treated with EVT and medical treatment consistent with national guidelines. The primary endpoint is the clinical outcome at 90 days between fCIS group versus pCIS group. The secondary endpoint is the influence of successful revascularization on outcomes for patients with fCIS or pCIS.