Mortality Risk in Acute Ischemic Stroke Patients With Large Vessel Occlusion Treated With Mechanical Thrombectomy

Background Recent randomized controlled clinical trials have provided solid evidence that mechanical thrombectomy (MT) coupled with best medical therapy (BMT) improve functional outcomes of acute ischemic stroke patients with large vessel occlusion compared with BMT alone. However, they provided inconclusive evidence on the benefit of MT on mortality. Methods and Results We evaluated the association of MT+BMT compared with BMT with the risk of 3-month mortality using aggregate data from all available randomized controlled clinical trials. We also sought to identify potential predictors on the mortality risk and performed univariate meta-regression analyses. Our literature search identified 11 eligible randomized controlled clinical trials, including a total of 2460 patients. The pooled rates of 3-month mortality were 15% (95% CI:12%-19%) and 19% (95% CI:16%-23%), respectively, in the MT+BMT and BMT groups. In the overall analysis MT+BMT was associated with a significantly lower risk for 3-month mortality compared with BMT (risk ratio=0.83, 95% CI:0.69-0.99; P=0.04), without heterogeneity across included studies (I²=3%, P for Cochran Q=0.41). No evidence of publication bias was present in funnel plot inspection and Egger statistical test (P=0.762). In meta-regression analyses no moderating effect on the aforementioned association was detected with patient age (P=0.254), sex (P=0.702), admission systolic blood pressure (P=0.601), admission glucose (P=0.277), onset-to-groin puncture time (P=0.985), administration of intravenous alteplase before MT (P=0.804), MT under general anesthesia (P=0.735), and successful reperfusion following MT (P=0.663). Conclusions Our meta-analysis provides evidence that MT+BMT reduces the risk of 3-month mortality compared with BMT alone. This association appears not to be moderated by individual patient or procedural characteristics.