Results of an international study exploring the effectiveness of a revolutionary stroke treatment may lead to a new lease on life for millions of sufferers previously facing disability or even death, Western researchers say. The findings were published today in the New England Journal of Medicine.
“This is a potential game-changer in the field of acute stroke,” said Clinical Neurological Sciences professor Dr. Jennifer Mandzia. “Patients with moderate-to-severe stroke and a proximal artery occlusion (blockage) in the brain, both young and old, have a treatment that has shown to improve functional outcome and reduces risk of death compared to standard of care.
“This is very exciting for our field and our patients.”
Led by researchers at the University of Calgary’s Hotchkiss Brain Institute, the international clinical trial included 22 locations in the United States, Ireland, South Korea and Canada. The London trial was led by Mandzia and Western professor emeritus Dr. David Pelz.
Known as ESCAPE – remarkably standing for ‘endovascular treatment for small core and anterior circulation proximal occlusion with emphasis on minimizing CT to recanalization times’ – the study showed a reduction in both disability and death among patients who suffered an acute ischemic stroke and received endovascular treatment within 12 hours of its onset.
Overall, positive outcomes for patients increased from 30 per cent to 55 per cent and, in many cases, instead of suffering major neurological disability, patients went home to resume their lives. The overall mortality rate was cut in half from 2-in-10 patients for standard care to 1-in-10.
That’s all good news for acute ischemic stroke sufferers, who account for 85 per cent of all stroke victims. An acute ischemic stroke involves 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 is to administer a drug called tPA – also known as a ‘clot buster’ drug – that dissolves the blood clot.
The studied procedure involved utilizing that standard care plus an endovascular treatment, performed by inserting a thin tube through an artery in the groin, up through the body, into the brain vessels to the clot. Performed 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.
More than 300 patients were examined for the study.
Endovascular treatment was first developed in the 1990s, but only recently has it been technically possible.
“It’s not that we’ve never done it. The difference is, we’ve never done it the way we’ve done it,” said Mandzia, a Lawson Health Research Institute researcher. “What we want to do with any sort of stroke care is prevent disability when people come out, so there was a definite improvement. We know that in patients who get the drug (tPA), it’s only effective in about 40 per cent of the cases. It can be pretty devastating. It’s pretty hard to get the clot out.”
The trial’s success 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 first endovascular treatment trial to demonstrate reduced mortality.
One of the key components of this study was timing of treatment.
“We have protocols where EMS identifies the patient and can bypass the emergency room and contact the neurology team directly,” she said. “We want to treat as quickly as possible. We strive for what we call ‘door-to-needle time’ of less than one hour. It’s not always possible, but LHSC (London Health Sciences Centre) has been working to always find ways to improve this.”
Mandzia added guidelines are currently being changed, based on this latest study, to become the new standard of care. For example, if a stroke patient arrived at a London hospital today, this procedure would be done, if the conditions were correct, she continued.
“It forces us to reorganize our stroke care,” she said. “If they arrived quickly, with the right location of the clot, had a good scan, we’d do it.”
These results are a “step forward” in getting handle on improving stroke care for patients.
“Stroke is ‘exciting’ because you can do something,” she said. “In other areas of neurology, you manage symptoms, which is important. But with this, you can actually see people walk out and have no disabilities. That’s what’s really satisfying.”