SELECT2: A Randomized Controlled Trial to Optimize Patient's Selection for Endovascular Treatment in Acute Ischemic Stroke

SELECT 2 is a prospective, phase III randomized, international, multicenter, assessor-blinded controlled trial evaluating the efficacy and safety of thrombectomy in patients with large core on either CT or advanced perfusion imaging treated within 0-24 hours from last known well. Patients with the final diagnosis of an acute ischemic stroke due to a large vessel occlusion in the distal ICA and MCA M1 who have large core on either CT (ASPECTS: 3-5) or advanced perfusion imaging (\[rCBF\<30%\] on CTP or \[ADC\<620\] on MRI: ≥50cc) or both within 0-24 hrs from last known well will be randomized in a 1:1 ratio into thrombectomy plus medical management vs medical management alone. Patient outcomes will be measured at baseline, 24 hours post, discharge, 30 days and 90 days. The primary endpoint is the Modified Rankin Scale (mRS) at 90 (+/- 15) days. The primary outcome is a shift on 90-day mRS. Secondary outcomes are favorable clinical outcomes: mRS score of 0-2, safety outcomes such the incidence of symptomatic intracranial hemorrhage (sICH per SITS-MOST) and Imaging endpoints such as infarct volume on MRI diffusion-weighted imaging (DWI) sequence (or CT if MRI not feasible) 24 to 72 hours after randomization. CT images will be read by iSchemaView automated ASPECTS as well as by a physician. In cases where there is disagreement, the physician reading will override the automated software reading. CT/MR perfusion images with mismatch determination will be read by iSchemaView automated RAPID software. All the images will be adjudicated by a blinded core lab at the University of Texas-Medical School at Houston. A maximum of 560 patients will be randomized across the study sites. Covariate adaptive randomization will be used to balance the distribution of important variables. Interim analyses will be conducted at 200 and 380 patients, at which time the study may stop for efficacy or futility.