283Endovascular thrombectomy as a means to improve survival in acute ischemic stroke - A meta-analysis

Background and purpose Although endovascular thrombectomy (EVT) in acute ischemic stroke (AIS) is guideline-recommended to improve functional recovery, thus far there are only inconclusive data from underpowered singular trials of EVT vs. medical therapy (MT) on mortality. We here aimed to perform a meta-analysis on short-term mortality in guideline-relevant EVT vs. MT randomized controlled trials (RCTs). Methods All randomized controlled trials (RCT) reporting EVT vs. MT in the latest 2018 American Stroke Association/American Heart Association (ASA/AHA) Guidelines were eligible for inclusion. Data were abstracted by two independent investigators and double-checked by four others. Study data were integrated using the Cochran-Mantel-Haenszel method and a random-effects model to compute summary statistics of risk ratios (RR) with 95% confidence intervals (CI). Ninety-day mortality and intracranial hemorrhage (ICH) were analyzed. Results Ten of the twelve guideline-relevant EVT vs. MT RCTs (DAWN, DEFUSE 3, ESCAPE, EXTEND-IA, MR CLEAN, MR RESCUE, REVASCAT, SWIFT PRIME, THERAPY, THRACE) with 2,313 patients were selected for inclusion. Studies IMS III and SYNTHESIS were excluded due to their very infrequent use of EVT. Stent retrievers (Trevo, Solitaire, Merci) were most frequently applied, followed by thrombus aspiration (Penumbra). Intravenous thrombolysis was administered in addition to EVT in the majority of patients. In the pooled meta-analysis of all eligible RCTs, EVT significantly reduced the risk for 90-day mortality by 3.7% compared to MT (15.0% vs. 18.7%; RR 0.81 with CI 0.68 to 0.98; p=0.03), accounting for a number-needed-to-treat of 27 to prevent one all-cause death. Trends were similar in early-window (RR 0.83) and late-window trials only (RR 0.76). There was no difference in the risk for ICH in EVT vs. MT (4.2% vs. 4.0%; RR 1.11 with CI 0.71 to 1.72; p=0.65). All included trials were published in high-quality journals and risk of bias was judged low. Conclusions This meta-analysis lends evidence to EVT benefits for survival already during the first 90 days after acute ischemic stroke. These results further highlight the evolution of interventional techniques in this setting.