Endovascular Treatment for Acute Ischemic Stroke

Study Questions:

What is the clinical benefit of endovascular therapy for treatment of acute ischemic stroke?


The SYNTHESIS Expansion trial investigators randomly assigned 362 patients with acute ischemic stroke, within 4.5 hours after onset, to endovascular therapy (intra-arterial thrombolysis with recombinant tissue plasminogen activator [t-PA], mechanical clot disruption or retrieval, or a combination of these approaches) or intravenous t-PA. The primary outcome was survival free of disability defined as a modified Rankin score of 0 or 1 (scale of 0-6, with 0 indicating no symptoms, 1 no clinically significant disability despite symptoms, and 6 death) at 3 months.


A total of 181 patients were assigned to each arm. The median time from stroke onset to the start of treatment was 3.75 hours for endovascular therapy and 2.75 hours for intravenous t-PA (p < 0.001). At 3 months, there was no difference in the patients alive without disability in each arm (30.4% vs. 34.8%). These differences remained nonsignificant after adjusting for age, sex, stroke severity, and atrial fibrillation status at baseline (adjusted odds ratio, 0.71; 95% confidence interval, 0.44-1.14; p = 0.16). Fatal or nonfatal symptomatic intracranial hemorrhage occurred in 6% of the patients in each group. No significant differences were observed between groups in the rates of other serious adverse events.


The investigators concluded that endovascular therapy is not superior to standard treatment with intravenous t-PA.


Endovascular therapy for stroke is associated with better recanalization rates compared with fibrinolytics, although the clinical impact of this approach has been questionable. This study suggests that endovascular therapy was not associated with a meaningful clinical benefit. It is possible that the extra 1 hour to re-perfusion in association with endovascular therapy negated any benefit of this approach. Nevertheless, until clinical benefits can be established, endovascular therapy should not be routinely used for treatment of ischemic stroke.

Clinical Topics: Cardiac Surgery, Dyslipidemia, Lipid Metabolism

Keywords: Thrombolytic Therapy, Stroke, Intracranial Hemorrhages, Mechanical Thrombolysis, Tissue Plasminogen Activator

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