By Brenda Mooney, Special to AHC Media

CALGARY, ALBERTA – New research holds the promise of changing how acute ischemic stroke is treated.

The ESCAPE (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times) trial indicates that endovascular treatment (ET), can dramatically improve patient outcomes after an acute ischemic stroke.In fact, the trial was stopped early because of efficacy.

Overall, positive outcomes for patients increased from 30% to 55% with the clot retrieval system, according to the study published online by the New England Journal of Medicine. The research also was presented at the American Heart Association's International Stroke Conference in Nashville earlier this month.

Instead of suffering major neurological disability, patients often were able to go home and resume their lives, according to the study led by researchers from the University of Calgary's Hotchkiss Brain Institute (HBI). The overall mortality rate was reduced 50% – from two in 10 patients for standard treatment of care to one in 10 patients with ET.

“Among patients with acute ischemic stroke with a proximal vessel occlusion, a small infarct core, and moderate-to-good collateral circulation, rapid endovascular treatment improved functional outcomes and reduced mortality,” the authors conclude.

“This is the most significant and fundamental change in acute ischemic stroke treatment in the last 20 years. These results will impact stroke care around the world," added senior author Michael Hill, MD, professor in the Cumming School of Medicine's departments of clinical neurosciences, and radiology and a neurologist with the Calgary Stroke Program of Alberta Health Services.

Currently, the international standard of care based on Canadian, U.S. and European guidelines is to administer tPA when appropriate to dissolve the blood clot.

In the ESCAPE trial, 316 patients who fit the criteria for ET and arrived for treatment within 12 hours of their stroke were randomized to standard medical care, including tPA administration where appropriate, or standard medical care plus ET.

Using an X-ray for image-guidance, ET is performed by inserting a thin tube into the artery in the groin, through the body, and into the brain vessels to the clot. The clot is then removed by a retrievable stent and pulled out, restoring blood flow to the brain.

Although endovascular treatments were first developed in the 1990s, ET has only recently been technically possible, partly because it requires very fast treatment and the use of brain and blood vessel imaging, according to the ESCAPE authors.

"Key reasons for the success of the trial were, firstly, selecting appropriate patients using novel imaging technology; secondly, better organization and workflow to expedite treatment; and thirdly, use of modern technology to open the blood vessels," said first author Mayank Goyal, MD, professor of radiology and clinical neurosciences at the Cumming School of Medicine and co-principal investigator of the ESCAPE trial. "We believe that with the combined results from this trial and other trials, this will become the standard of care."

ESCAPE is the second ET trial that demonstrates the efficacy of the treatment and the first trial to demonstrate reduced mortality. The previous trial, known as MR. CLEAN (Multi center Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands), was published in December 2014.

 The current study included 22 sites worldwide and patients in the U.S., U.K., Ireland and South Korea. Canada had 11 participating hospitals and enrolled two-thirds of the patients.