University of Calgary's Hotchkiss Brain Institute researchers with the Calgary Stroke Program at Foothills Medical Centre revolutionized treatment for stroke with the ESCAPE Trial , proving that a clot retrieval procedure known as endovascular thrombectomy (EVT) can dramatically improve patient outcomes after an acute ischemic stroke caused by a blockage in a large-sized blood vessel.
Building on that knowledge, the team launched the ESCAPE-MeVO clinical trial to assess whether ischemic stroke patients with blockages in smaller medium-sized vessels could also benefit from EVT. Ischemic strokes are the most common form of stroke. The study, published in the New England Journal of Medicine, found that EVT does not result in improved outcomes.
"When someone has a stroke, it's critical that doctors know what the best approach is for each situation. Brain cells die quickly when blood flow stops," says Dr. Mayank Goyal, MD, PhD, interventional neuroradiologist, clinical professor at the Cumming School of Medicine (CSM) and study co-principal investigator. "The brain is fed by a network of arteries of varying size. Our findings show patients with blockages in medium-sized vessels in the brain who had endovascular treatment did not do any better and did not see any improvement compared to patients who had the standard of care."
The international study included 530 patients at 58 sites in five countries. Patients were randomly allocated into two groups; one group received usual care, the second received EVT plus usual care. Patients were assessed 90 days post-stroke. Outcomes were measured using the modified Rankin Score, a clinical tool that measures the level of disability a person experiences after a stroke, and the Barthel Index score that measures a patient's ability to do daily tasks.
"Our findings will help doctors better determine the best treatment for their patient," says Dr. Michael Hill, MD, neurologist, professor at the CSM and study co-principal investigator. "Knowing usual medical care, often with thrombolytic ("clot-busting") drugs, is best for blockages in medium-sized vessels helps with resourcing and ensuring each patient is getting the right care for their situation."
Hill says the results are especially important for doctors who see stroke patients at smaller centres, and rural locations where EVT may not be available. The study will continue patient follow-up to one-year see whether a late benefit emerges with longer duration of evaluation.
"Ultimately, we do this research because we want to improve treatments for patients and reduce death and disability from stroke," says Goyal. "This study helps us better understand when EVT is effective and when it isn't. That knowledge is important."
Goyal and Hill are presented the results at the International Stroke Conference in Los Angeles, California, US on February 5, 2024.
