Results from two studies presented at the International Stroke Conference 2013 showed similar outcomes for endovascular therapy and intravenous tissue plasminogen activator for the treatment of patients with acute ischemic stroke.
"The development of more effective intravenous lytic agents and endovascular devices to treat patients with acute ischemic stroke is imperative, since the majority of such patients still have substantial disability after treatment, as these trials show," Marc I. Chimowitz, MB, ChB, from the department of neurosciences at Medical University of South Carolina, wrote in a commentary published in The New England Journal of Medicine.
Comparison of endovascular therapy vs. tPA
For one study, Alfonso Ciccone, MD, from the stroke unit and department of neurology at Niguarda Ca' Granda Hospital, Italy, and colleagues analyzed 362 patients with acute ischemic stroke. Within 4.5 hours after stroke onset, patients were randomly assigned to endovascular therapy (intraarterial thrombolysis with recombinant tissue plasimogen activator (tPA), mechanical clot disruption or retrieval, or a combination of approaches; n=181) or IV tPA (n=181). The primary outcome was survival without disability at 3 months.
At 3 months, 30.4% of the endovascular therapy group and 34.8% of the intravenous tPA group were alive without disability (OR=0.71; 95% CI, 0.44-1.14). Six percent of patients in each group experienced a fatal or nonfatal intracranial hemorrhage within 7 days. The researchers found no significant differences in rates of other serious adverse events or case fatality rate between the endovascular therapy and tPA groups.
"This trial did not show that endovascular therapy achieves superior outcomes as compared with IV thrombolysis, and our findings do not provide support for the use of the more invasive and expensive endovascular therapy over intravenous treatment,” the researchers wrote in the study, which was simultaneously published in NEJM.
Similar safety outcomes reported
Functional dependence at 90 days after a stroke was no better for patients who received endovascular therapy and IV tPA or tPA alone, according to results of a second study.
The IMS III study included 656 patients with moderate-to-severe acute ischemic stroke randomly assigned to tPA within 3 hours of symptom onset plus endovascular therapy (n=434) or tPA alone (n=222). The study was stopped early after the study’s Data and Safety Monitoring Board noticed that 90-day outcomes were not different between the two groups.
Results showed no significant difference in the proportion of participants with a modified Rankin score of 2 or less at 90 days (40.8% with endovascular therapy vs. 38.7% with tPA; absolute adjusted difference, 1.5 percentage points) and no significant difference for predefined subgroups of patients with a National Institutes of Health Stroke Scale score of 20 or higher (6.8 percentage points) or 19 or lower (–1 percentage point).
Mortality at 90 days was 19.1% in patients assigned endovascular therapy and 21.6% in patients assigned tPA (P=.52). The proportion of patients who had symptomatic intracerebral hemorrhage within 30 hours after tPA initiation was also similar (6.2% vs. 5.9%, respectively; P=.83).
Joseph P. Broderick
"Endovascular therapy is a tool that is not going away," Joseph P. Broderick, MD, from the department of neurology at the University of Cincinnati Neuroscience Institute, said during a press conference. "The issue is how best to use the devices to treat the population of stroke patients."
Trial of imaging selection
Neuroimaging did not identify patients who could benefit from endovascular therapy after acute ischemic stroke, according to a third study presented at the conference and simultaneously published in NEJM.
The MR RESCUE trial evaluated outcomes in 118 patients (mean age, 65.5 years; mean time to enrollment, 5.5 hours). Within 8 hours of acute ischemic stroke, the patients were randomly assigned to mechanical embolectomy (Merci Retriever or Penumbra System) or to standard care. All patients underwent MRI or CT of the brain before treatment.