Researchers find new therapy benefits stroke patients
Toronto, February 11, 2015
(l to r) Dr. Gustavo Saposnik, Dr. Aditya Bharatha and Dr. Walter Montanera
St. Michael’s Hospital was one of 11 Canadian sites that participated in a randomized controlled trial that showed a clot retrieval procedure known as endovascular treatment can dramatically improve patient outcomes after an acute ischemic stroke.
The study, led by researchers at the University of Calgary’s Hotchkiss Brain Institute, showed a dramatic improvement in outcomes and a reduction in deaths from stroke.
The results of the study were published today in the online edition of the New England Journal of Medicine.
Overall, positive outcomes for patients increased from 30 per cent to 55 per cent. In many cases, instead of suffering major neurological disability, patients went home to resume their lives. The overall mortality rate was reduced from two in 10 patients for standard treatment of care to one in 10 patients – a 50 per cent reduction with ET.
St. Michael’s “acute stroke” team participated in the trial, headed locally by Dr. Aditya Bharatha (co-principal investigator, interventional neuroradiology) and Dr. Gustavo Saposnik (co-principal investigator, neurology).
“This important trial highlights the effectiveness of endovascular (intra-arterial) treatments to rapidly reopen blocked brain arteries in people having an acute stroke,” said Dr. Walter Montanera, an interventional neuroradiologist at St. Michael’s who was a member of the research study’s central advisory committee.
The clinical trial, known as ESCAPE (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times), shows there is a marked reduction in both disability and death among patients who receive ET for acute ischemic stroke. Ischemic stroke is caused by a sudden blockage of an artery to the brain that deprives the brain of critical nutrients, such as glucose and oxygen. Currently, the international standard of care based on Canadian, U.S. and European guidelines is to administer a drug called 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 (which included the clot-busting drug tPA where appropriate) or standard medical care plus ET. 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. This is done under image-guided care using an X-ray. The clot is then removed by a retrievable stent and pulled out, restoring blood flow to the brain.
Endovascular treatments were first developed in the 1990s, but ET has only recently been technically possible. The ESCAPE team says the success of the trial can be credited to fast treatment and the use of brain and blood vessel imaging. In ESCAPE, researchers were on average two hours faster in opening the blocked blood vessels than in previously reported trials.
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.
The study included 22 sites worldwide and patients in the United States, United Kingdom, Ireland and South Korea. Canada had 11 participating hospitals and enrolled two-thirds of the patients.
The study was funded by the Heart and Stroke Foundation of Canada, Alberta Innovates-Health Solutions and Medtronic.
About St. Michael's Hospital
St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.
For more information, or to arrange an interview with Dr. Montanera, please contact:
Manager, Media Strategy, St. Michael's Hospital