Abstract 76: Stroke Imaging Selection For Endovascular Therapy In The Extended Window: Systematic Review And Meta-analysis.

Abstract

Introduction: The best stroke imaging modality to select patients for endovascular therapy (EVT) beyond 6 hours (extended window) is not well established. Objective: To assess the value of additional advanced imaging. Methods: A meta-analysis in accordance with PRISMA guidelines was conducted. We searched on MEDLINE/Pubmed, SCOPUS, EMBASE, CENTRAL, and reference lists until July 22, 2021, including randomized clinical trials (RCT) and observational studies describing 90 days outcomes in anterior circulation large vessel occlusion (LVO) ischemic stroke. Our primary outcome was functional independence, defined as modified Rankin Scale score (mRS): 0-2. Secondary outcomes were mortality and symptomatic intracranial hemorrhage (sICH). We used fixed effects model to estimate the pooled mRS for all patients and the proportion of patients with each outcome, both for all studies and by imaging modality. Results: Four RCTs (n=236) and 19 observational studies (n=1495) that met the inclusion criteria were included for meta-analysis. Patients selected by advanced imaging had a pooled estimate of functional independence in 45% (95% confidence interval [CI], 40% to 50% I2=62%), and 51% (95%CI, 43% to 60% I2=68.2%) without additional imaging. [Low certainty of evidence] Pooled mortality rate was 13% (95%CI,9% to 17%, I2=57.5%) vs 16% (95%CI,10% to 23%, I2=63.9), symptomatic intracranial hemorrhage (sICH) was 5% (95%CI,2% to 8% I2=33.6%) vs 4% (95%CI,2% to 7%, I2=66.4%) in both groups respectively [Low certainty] The overall pooled estimate of functional independence was 47% (95%CI, 43% to 52%, I2=65.2%) [Low certainty], with mean mRS of 2.88 (95%IC, 2.36 to 3.4) [moderate certainty] in all included patients indistinctly of the imaging modality. Limitations: substantial heterogenicity and not direct comparison of imaging modalities in most of the studies. Conclusion: This meta-analysis suggests that functional independence in patients with stroke who underwent EVT on the extended window can be achieved in a high proportion of patients despite the use or not of additional advanced imaging. Both groups also presented similar mortality and sICH.