Imaging-Based Patient Selection and Endovascular Therapy of Ischemic Stroke: A Stratified Meta-Analysis

The positive results of recent trials for the treatment of acute ischemic stroke have highlighted the importance of imaging selection before endovascular therapy. We performed a stratified meta-analysis to confirm this new understanding. We searched EMBASE, PubMed, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov in April 2015 for randomized controlled trials evaluating the effect of endovascular treatment in patients with acute ischemic stroke. The meta-analysis was stratified by whether computed tomographic angiography (CTA) was used to select patients. Outcome data were pooled using fixed-effects models. Seven randomized controlled trials with 2217 patients were included in this study. Endovascular therapy significantly increased the rate of 90-day functional independence (a modified Rankin score of 0-2) in patients with a CTA-confirmed large-vessel occlusion (relative risk [RR] = 1.75, 95% confidence interval [CI]: 1.48-2.06, I = 0.0%), and reduced 90-day mortality in patients with occlusion stroke with a small ischemic core (RR = 0.58, 95% CI: 0.37-0.89, I = 0.0%). The functional benefit was significantly greater in patients with CTA-based selection than in those without (Z = 5.04, P < 0.001). The mortality benefit was significantly greater in patients with a large-vessel occlusion and a small ischemic core than in those without CTA-based selection (Z = 2.04, P = 0.041). There was no evidence of between-study heterogeneity or publication bias. This meta-analysis showed the effect of vascular imaging on identifying patients with acute ischemic stroke with a proximal vessel occlusion and a small ischemic core, who would benefit from endovascular therapy.