Abstract

Objective:: Mechanical thrombectomy is the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS) up to 6 h after onset. Recent trials have demonstrated a benefit for wake-up strokes and patients beyond 6 h. Methods:: A systematic literature review was conducted for multicenter randomized clinical trials (RCTs) investigating endovascular stroke treatment using perfusion imaging to identify patients that may benefit from mechanical thrombectomy for AIS beyond 6 h of onset. Random effects meta-analysis was used to analyze the following outcomes: 90-day functional independence rates with modified Rankin Scale (mRS 2), 90-day mortality, and symptomatic intracranial hemorrhage (sICH) rates. Further stratification was carried out by age and presentation. Results:: Two multicenter RCT's were included as follows: DAWN and DEFUSE-3. Pooled 90-day functional independence rates favored endovascular management (odds ratio [OR] 5.01; P < 0.00001). Subgroup analysis demonstrated continued 90-day functional independence benefit for endovascular management regardless of age (80 years, OR 5.65, P = 0.01; 80 years, OR 4.92, P < 0.00001). When stratified for the manner of stroke discovery, 90-day functional independence rates favored endovascular management for wake-up strokes (OR 8.74, P < 0.00001) and known-time onset strokes (OR 5.08, 95% confidence interval [CI] 2.0412.65, P = 0.0005), although no benefit was observed for unwitnessed strokes (OR 1.64, 95% CI 0.1716.04, P = 0.67). No difference observed in 90-day mortality rates (OR 0.71; P = 0.14) or in SICH rates (OR 1.67; P = 0.29). Conclusions:: This meta-analysis reinforces that endovascular management is superior to standard medical management alone for the treatment of AIS due to LVO beyond 6 h of onset in patients with perfusion-imaging selection.