University of Calgary researchers Mayank Goyal, left, Andrew Demchuk and Michael Hill in the neuro-angiography suite where endovascular treatment is performed. Photo by Riley Brandt, University of Calgary
A recent stroke clinical trial led by the University of Calgary is one of five studies that has resulted in a change in protocol for stroke care across Canada.
Written by a consortium of physicians on behalf of the Heart and Stroke Foundation, the 2015 update of the Canadian Stroke Best Practice Recommendations Hyperacute Stroke Care Guidelines have included new recommendations for the use of endovascular treatment (ET) for patients with acute ischemic stroke. Ischemic stroke is caused by a sudden blockage of an artery to the brain, depriving it of glucose and oxygen that are essential for proper brain function.
Clot retrieval operation helps patients after acute ischemic stroke
Earlier this year, researchers at the University of Calgary’s Hotchkiss Brain Institute (HBI), Cumming School of Medicine, and Foothills Medical Centre completed an international randomized controlled trial showing that ET— a clot retrieval process — can dramatically improve patient outcomes after an acute ischemic stroke.
The results of the study, known as ESCAPE (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times), were published in the Feb. 11 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.
‘Now offering the therapy routinely for patients’
“While it will still take some time before this procedure is available in all major hospitals, in Canada we are in great shape because we’ve had 11 major hospitals participate in the trial. We have been performing ET for two years and are now offering the therapy routinely for patients,” says Dr. Michael Hill, a professor in the departments of clinical neurosciences, community health sciences, medicine and radiology at the University of Calgary, and a member of the HBI.
Hill says the adoption of the procedure into the guidelines is a really important example of how clinical research in Canada changes health care for the better, but adds there is still work to be done.
“Up to 45 per cent of our patients did not do well, so there is still a lot of work to continue improving the outcome of stroke patients.”
About endovascular treatment
Endovascular treatment 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, restoring blood flow to the brain.
Endovascular treatments were first developed in the 1990s, but ET has only recently been technically possible.
Prior to these new recommendations, the international standard of care based on Canadian, U.S. and European guidelines was to administer a drug called tPA when appropriate. Known as a “clot buster,” the drug dissolves the blood clot.
ESCAPE trial demonstrates reduced mortality
Hill co-led the ESCAPE trial with fellow university researchers and HBI members Drs. Mayank Goyal and Andrew Demchuk. ESCAPE was the second ET trial that demonstrated 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. There have also been three subsequent smaller studies published in the NEJM that demonstrate the efficacy of endovascular treatment for stroke treatment.
The revised Hyperacute Stroke Care Guidelines are published in the International Journal of Stroke.
Led by the HBI, Brain and Mental Health is one of six strategic research themes guiding the University of Calgary toward its Eyes High goals.