A Trial of Imaging Selection and Endovascular Treatment for Ischemic Stroke

Abstract

BACKGROUND Whether brain imaging can identify patients who are most likely to benefit from therapies for acute ischemic stroke and whether endovascular thrombectomy improves clinical outcomes in such patients remains unclear. METHODS In this study, we randomly assigned patients within 8 hours after the onset of large-vessel, anterior-circulation strokes to undergo mechanical embolectomy (Merci Retriever or Penumbra System) or receive standard care. All patients underwent pretreatment computed tomography or magnetic resonance imaging of the brain. Randomization was stratified according to whether the patient had a favorable penumbral pattern (substantial salvageable tissue and small infarct core) or a non-penumbral pattern (large core or small or absent penumbra). We assessed outcomes using the 90-day modified Rankin scale, ranging from 0 (no symptoms) to 6 (dead). RESULTS Among 118 eligible patients, the mean age was 65.5 years, the mean time to enrollment was 5.5 hours, and 58% had a favorable penumbral pattern. Revascularization in the embolectomy group was achieved in 67% of the patients. Ninety-day mortality was 21%, and the rate of symptomatic intracranial hemorrhage was 4%; neither rate differed across groups. Among all patients, mean scores on the modified Rankin scale did not differ between embolectomy and standard care (3.9 vs. 3.9, P = 0.99). Embolectomy was not superior to standard care in patients with either a favorable penumbral pattern (mean score, 3.9 vs. 3.4; P = 0.23) or a nonpenumbral pattern (mean score, 4.0 vs. 4.4; P = 0.32). In the primary analysis of scores on the 90-day modified Rankin scale, there was no interaction between the pretreatment imaging pattern and treatment assignment (P = 0.14). CONCLUSIONS A favorable penumbral pattern on neuroimaging did not identify patients who would differentially benefit from endovascular therapy for acute ischemic stroke, nor was embolectomy shown to be superior to standard care. (Funded by the National Institute of Neurological Disorders and Stroke; MR RESCUE ClinicalTrials.gov number, NCT00389467.)

Brazilian guidelines for endovascular treatment of patients with acute ischemic stroke

“…This choice was driven by the findings of SWIFT and TREVO-2, two head-to-head randomized clinical trials comparing the reperfusion performance of stent retrievers against the MERCI device, where stent retrievers yielded a four-times higher chance of post-procedure reperfusion and higher rates of good clinical outcome 32,33 . Indeed, prior trials that did not show benefit of endovascular treatment used other first generation mechanical thrombectomy devices (mainly the MERCI device) or intra-arterial injection of TPA 21,22,34 . One assumed reason for the absence of clinical benefit in those earlier trials was the low rate of successful reperfusion.…”

Snapshot MR Technique to Measure OEF Using Rapid Frequency Mapping

“…In the acute setting, the recently reported DEFUSE II (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution II) trial showed the feasibility of using magnetic resonance imaging (MRI) to perform rapid and reliable triage of patients for thrombolytic therapy. 5 In contrast, the MR-RESCUE (Mechanical Retrieval and REcanalization of Stroke Clots Using Embolectomy) clinical trial 6 showed inconclusive results for the use of imaging in the acute stroke setting. Thus, the dependence of perfusionweighted/diffusion-weighted imaging mismatch for triage has led to both positive and negative results in large multicenter trials.…”

Statement of ESMINT and ESNR regarding recent trials evaluating the endovascular treatment at the acute stage of ischemic stroke

“…Three recent, simultaneous publications report the neutral results of three randomized studies (SYNTHESIS Expansion, Interventional Management of Stroke (IMS) III, and Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE)) comparing IV thrombolysis therapy or standard care (MR RESCUE) to the endovascular treatment (EVT) of acute ischemic stroke (AIS) [1][2][3]. The results of these three trials might lead to the erroneous conclusion that endovascular treatment has no or little place in the management of AIS.…”