Endovascular Thrombectomy for Low ASPECTS Large Vessel Occlusion Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND: The current American Heart Association guidelines for acute ischemic stroke reserve Grade 1A recommendation for the use of endovascular thrombectomy (EVT) for patients with an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of ≥6.

OBJECTIVE: We aim to determine the safety and efficacy of EVT for large vessel occlusion ischemic stroke patients with low ASPECTS (5 or less).

METHODS: Medline, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched for studies appraising the outcomes of EVT for low ASPECTS ischemic stroke. A meta-analysis of proportions compared the clinical outcomes of patients undergoing EVT and those receiving best medical therapy only.

RESULTS: Nine studies (1,196 patients) were included. There was a trend (p = 0.11) toward a higher rate of symptomatic intracranial hemorrhage (sICH) in the EVT group (9.2%; 95% CI 6.1-13.6; I2 53.37%) compared to the medical group (5.5%; 95% CI 3.7-8.1; I2 0%). There was no difference (p = 0.41) in the pooled 90-day mortality of EVT patients (30.7%; 95% CI 21.7-41.5; I2 84.23%) and medical patients (36.6%; 95% CI 26.4-48.1; I2 76.2%). EVT patients had better (p = 0.001) 90-day outcomes, with 27.7% (95% CI 21.8-34.5; I2 62.08%) of patients attaining a modified Rankin Scale of 0-2 compared to only 3.7% (95% CI 2.3-5.9; I2 87.21%) in the medical group.

CONCLUSIONS: This meta-analysis demonstrates a trend in higher sICH among low ASPECTS patients undergoing EVT. Despite this, a significant proportion of this subset of patients still achieved good functional outcomes at 90 days. Randomized trials are necessary to substantiate this result as significant bias is inherent in the observational studies included in this review.