Canadian research could pave the way to new stroke treatment
A clinical trial testing out a novel way to treat stroke patients that was conceived, designed and tested out by Canadian doctors has returned with promising results.
Canadian scientists out of the University of Calgary say their clot retrieval procedure, called endovascular treatment (ET), could be a game-changer for patients who turn up in hospital after a stroke.
The trials were run out of seven Canadian cities, along with hospitals in the U.S., Ireland and South Korea. Twenty-two sites – half of which were in Canada – were involved in the study.
“What I think will happen is there will be a change in guidelines for acute ischemic stroke and [endovascular treatment] will become a standard way of treatment that’ll be slowly implemented across the country and around the world,” Dr. Mayank Goyal told Global News.
He’s one of the lead scientists for the clinical trial and a professor of radiology at the University of Calgary.
His team is calling its results the “most significant and fundamental change” in acute ischemic stroke treatment in the past two decades.
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. Most strokes are of this variety, Goyal says.
Right now, it’s treated by administering a drug called tPA when appropriate – the drug is a ‘clot buster’ and dissolves the blood clot.
Goyal says that endovascular treatment is relatively new – ushered in around the 1990s – and with a mixed bag of results. Some scientists testing their methodology have trouble with getting to the clot quickly and identifying the right patient for the procedure.
In ET, a thin tube is inserted into the artery in the groin. It travels through the body and into the brain vessels to the clot. X-ray imaging helps with guiding the stent. Once it reaches the clot, it’s pulled out restoring blood flow to the brain.
Goyal says that previous attempts in the past could take more than 200 minutes – a lengthy time during an incredibly critical period for stroke victims. Because the team zeroed in on speed, efficiency in diagnosing, imaging and coordination, their procedure is completed within 84 minutes, he said.
That’s roughly a two-hour difference.
“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,” Goyal explained.
In the clinical trial, 316 patients who fit the criteria for ET and arrived in hospital for treatment within 12 hours of their stroke were assigned to either standard medical care using the tPA drug or the standard medical care plus ET.
Turns out, patients randomized to the endovascular treatment had better outcomes. The overall mortality rate was reduced from two in 10 patients with the standard care of treatment to one in 10 for patients who had ET.
Fifty-five per cent of patients who had the novel treatment had positive outcomes which mean that they were able to go home and resume their lives without major neurological disabilities. In the control arm, 30 per cent of the group had positive outcomes.
“This is the first time in ET that we’ve been able to show this improvement in mortality,” Goyal said.
He and his colleagues – Dr. Michael Hill and Dr. Andrew Demchuk – travelled to the global sites to train doctors on imaging patients, coordinating care and carrying out the procedure. Calgary, Saskatoon, Halifax, Toronto, Edmonton, Ottawa, London and Montreal were among the Canadian cities.
The U.S. cities included in the study were: Pittsburgh, Pennsylvania; Denver, Colorado; Chattanooga, Tennessee; Charleston, South Carolina; Philadelphia, Pennsylvania and Abington, Massachusetts. And abroad, hospitals in Seoul and Incheon, South Korea as well as Belfast and Dublin, Ireland were involved.
“What we’ve been able to show is this can be done within many centres around the world with imagining facilities that aren’t complex,” Goyal explained.
His team’s next steps are to explore how to make the process seamless. A lot more needs to be done to ensure frontline health care workers can match the right patient to the right treatment, meanwhile coordination in hospital care could speed up the process.
The University of Calgary findings were published online Wednesday and will appear in the March 19 print edition of the New England Journal of Medicine.
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