LAUSR

Background and Purpose— In acute ischemic stroke patients, diffusion-weighted imaging (DWI)–Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is correlated with infarct volume and is an independent factor of functional outcome. Patients with pretreatment DWI-ASPECTS ⩽6 were excluded or under-represented in the recent randomized mechanical thrombectomy trials. Our aim was to assess the impact of reperfusion in pretreatment DWI-ASPECTS ⩽6 patients treated with mechanical thrombectomy. Methods— We analyzed data collected between January 2012 and August 2015 in a bicentric prospective clinical registry of consecutive acute ischemic stroke patients treated with mechanical thrombectomy. Every patient with a documented internal carotid artery or middle cerebral artery occlusion with pretreatment DWI-ASPECTS ⩽6 was eligible for this study. The primary end point was a favorable outcome defined by a modified Rankin Scale score ⩽2 at 90 days. Results— Two hundred and eighteen patients with a DWI-ASPECTS ⩽6 were included. Among them, 145 (66%) patients had successful reperfusion at the end of mechanical thrombectomy. Reperfused patients had an increased rate of favorable outcome (38.7% versus 17.4%; P=0.002) and a decreased rate of mortality at 3 months (22.5% versus 39.1%; P=0.013) compared with nonreperfused patients. The symptomatic intracranial hemorrhage rate was not different between the 2 groups (13.0% versus 14.1%; P=0.83). However, in patients with DWI-ASPECTS <5, favorable outcome was low (13.0% versus 9.5%; P=0.68) with a high mortality rate (45.7% versus 57.1%; P=0.38) with or without successful reperfusion. Conclusions— Successful reperfusion is associated with reduced mortality and disability in patients with a pretreatment DWI-ASPECTS ⩽6. Further data from randomized studies are needed, particularly in patients with DWI-ASPECTS <5.