Early Intervention with Stent Retrievers Improves Outcomes for Ischemic Stroke Patients

New research has shown that restoration of blood flow to the brain within two and a half hours from the onset of the first signs of acute ischemic stroke resulted in none, or only minimal disability in 91% of patients.

Endovascular therapy in the early stages of the onset of stroke symptoms significantly improved functional outcomes for patients with acute ischemic stroke. Nearly 90% of all strokes are acute ischemic strokes, which deprive brain tissue of their oxygen supply within a short period of time and can result in long-term disabilities for patients. Stent retrievers are devices that are threaded into blocked arteries to remove blood clots in the head, using X-Ray guidance. Another recent advance in stroke care is treatment with Intravenous Tissue Plasminogen Activator (IV t-PA), a protein that removes blood clots.

The research results were published in the April 2016, online issue of the journal Radiology. The researchers used patient data from the Solitaire With the Intention For Thrombectomy as PRIMary Endovascular Treatment (SWIFT PRIME) trial. The patients had been treated with IV t-PA and stent retrievers. The researchers then analyzed the data to see whether there was any clinical relevance to the time interval from the onset of symptoms to clot removal.

The researchers found that restoring blood flow to the brain within 2.5 hours of the onset of symptoms resulted in functional independence and minimal disability in most patients. Patients treated between 2.5 and 3.5 hours after the onset of a stroke had a 10% lower likelihood of functional independence, and every additional 60-minute delay beyond 3.5 hours resulted in a 20% lower likelihood of functional independence. The researchers also concluded that inter-facility transfers resulted in significant delays in patient treatment.

Lead author of the study, Mayank Goyal, MD, FRCPC, University of Calgary (Calgary, AB, Canada), said, “The earlier that patients with acute ischemic stroke get to a hospital offering the appropriate treatment, the higher the likelihood is of a good outcome. Two-thirds of the patients in our study went directly to the endovascular-capable center and one-third went to a primary stroke center. For those who went to the stroke center, there was a loss of about two hours in overall workflow, which is pretty significant. Given the substantial decrease in functional independence with increase in time to restoration of blood flow, every step in the work up and treatment of these patients should be weighed against the time spent versus the potential benefit. Analysis of Workflow and Time to Treatment and Its Impact on Outcome in Endovascular Treatment of Acute Ischemic Stroke Outcome: Results from the SWIFT PRIME Randomized Controlled Trial.”

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