A Trial of Imaging Selection and Endovascular Treatment for Ischemic Stroke

Study Questions:

Can brain imaging identify patients who are most likely to benefit from therapies for acute ischemic stroke?


The authors randomly assigned patients presenting 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 nonpenumbral pattern (large core or small or absent penumbra). Outcomes were assessed using the 90-day modified Rankin scale, ranging from 0 (no symptoms) to 6 (dead).


The study enrolled 118 patients of whom 58% had a favorable penumbral pattern. There was no difference in 90-day mortality between the two groups. The mean scores on the modified Rankin scale did not differ between embolectomy and standard care (3.9 vs. 3.9, p = 0.99). There was no interaction between the pretreatment imaging pattern and treatment assignment, and 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).


The authors concluded that a favorable penumbral pattern on neuroimaging did not identify patients who would differentially benefit from endovascular therapy for acute ischemic stroke.


Despite much initial enthusiasm, endovascular therapy has not proven to be beneficial in patients presenting with large anterior circulation stroke. This study suggests that neuroimaging is unlikely to identify a subset of patients who would benefit from endovascular therapy. The outcome of these patients remains poor and further research is warranted to develop strategies for improving neurological recovery in this population.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Stroke, Pyridinolcarbamate, Neuroimaging, Embolectomy

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