Michael D. Hill, MD, and Mayank Goyal, MD, University of Calgary, Calgary, Alberta, Canada, jointly presented the results of the ESCAPE trial [Goyal M et al. N Engl J Med. 2015], a phase 3, multicenter, prospective, randomized, open-label, controlled trial with a blinded outcome evaluation. The study was conducted at 22 centers in Canada, the United States, South Korea, the United Kingdom, and Ireland. Patients were randomized in a 1:1 ratio to modern endovascular treatment plus guideline-based care (intervention group) or guideline-based care alone (control).

Eligible patients had to have acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] > 5) within a 12-hour window and good premorbid functional status. There was no upper age limit for participants in the study. Results from the patient’s imaging were required to show a small core, proximal intracranial artery occlusion, and moderate-to-good collateral circulation using computed tomography (CT) or multiphase CT angiography. The use of magnetic resonance imaging was discouraged.

The study focused on rapid endovascular treatment, with a target time of 60 minutes from head CT (first slice) to groin puncture and 90 minutes from head CT to the first reperfusion, to enable fast imaging and interpretation. Intravenous tissue plasminogen activator (tPA) was administered to appropriate patients according to standard of care. The investigators were encouraged to use retrievable stents and balloon guide catheters and to avoid general anesthesia. The primary outcome was the modified Rankin scale (mRS) score 90 days post-randomization. Safety end points were also measured.

The ESCAPE trial steering committee stopped recruitment in October 2014 after the presentation of the MR CLEAN trial results [Berkhemer OA et al. N Engl J Med. 2015]. A planned interim analysis was completed early, and ESCAPE was discontinued by the Data Safety Monitoring Board in November 2014 because the prespecified efficacy boundary had been crossed.

A total of 316 patients were enrolled, 165 in the intervention group and 150 in the control group; 1 patient was excluded due to informed consent issues. Baseline characteristics were similar in the 2 groups: median age close to 71 years, > 50% women, median NIHSS scores around 16, and approximately one quarter with occlusion of the internal carotid artery. In the intervention group, the median time from CT to groin puncture was 51 minutes, from CT to first reperfusion was 84 minutes, and from stroke onset to first reperfusion was 241 minutes. Around 75% of each group received intravenous tPA.

Efficacy and safety end points are presented in Table 1. Benefits in mortality, morbidity, and quality of life were observed when the intervention arm was compared with the control arm.

Additional subgroup analyses favored intervention across all groups including patients over the age of 80 years. The investigators concluded that endovascular thrombectomy is a safe intervention, reducing mortality and disability when patients are carefully selected using imaging, when treatment is administered very quickly, and when safe, effective technology, such as retrievable stents, is employed.