Methods:

The investigators performed a prespecified subgroup analysis of the MR CLEAN randomized controlled trial, which enrolled patients with acute ischemic stroke caused by an intracranial occlusion in the distal intracranial internal carotid artery, middle cerebral artery (M1 or M2 branch), or anterior cerebral artery (A1 or A2 branch). Patients in the MR CLEAN trial were randomized to IAT plus usual care versus usual care alone. Inclusion of patients with ECD was left to the discretion of the treating physician. ECD was defined as stenosis >50% or occlusion of the carotid on the same side as the intracranial occlusion. In this analysis, results were reported as the odds ratio (OR) for a shift in the direction of a better outcome on the 3-month modified Rankin scale (mRS), a 7-point scale of disability and dependence ranging from no symptoms (0) to death (6). Results were adjusted for age, baseline stroke severity, time from onset to randomization, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial ICA terminus occlusion.