Landmark Study Shows Clot Removal Reduces Mortality, Improves Patient Outcome in Large-Vessel Stroke
PITTSBURGH, Feb. 11, 2015
– Researchers have completed an international, randomized, controlled trial showing that a clot-retrieval procedure, known as endovascular treatment (ET), can dramatically improve patient outcomes after an acute ischemic stroke. The study, in which the University of Pittsburgh
enrolled more participants than any other American site, also shows a dramatic reduction in deaths from stroke. The results were published in the Feb. 11 online edition of the New England Journal of Medicine
The results of this landmark study will be published in the March 19 print edition of NEJM and presented at the American Heart Association’s International Stroke Conference in Nashville, Tenn.
Overall, positive outcomes for patients increased from 30 percent to 55 percent. In many cases, instead of suffering major neurological disability, patients went home to resume their lives. Led by researchers at the University of Calgary
, the study found that overall mortality rate was reduced from two in 10 patients for standard treatment of care to one in 10 patients – a 50 percent reduction with ET.
“These results mean we are on the verge of a revolution in stroke care,” said Tudor Jovin, M.D
., associate professor of neurology and neurological surgery, director of the UPMC Stroke Institute
and leader of the Pitt arm of the study. “This is a devastating condition from the standpoint of death and disability. Finally, we are able to offer these patients a treatment that really works.”
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 “clot buster” drug called tPA, to attempt to dissolve the blood clot.
In this trial, known as ESCAPE (Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times), 316 patients who fit the criteria for ET and arrived for treatment within 12 hours of their stroke were randomly assigned to receive either standard medical care, which included 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 aorta and into the brain vessels to the clot using X-ray-guided imaging. A retrievable stent opens the blocked vessel to restore blood flow and then withdrawn, pulling the clot out with it.
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 very fast treatment and the use of brain and blood vessel imaging. 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 (Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands), was published in NEJM in December 2014.
ESCAPE included 22 sites worldwide and patients in the U.S., U.K., Ireland and South Korea. Canada had 11 participating hospitals and enrolled two-thirds of the patients.
“This was a trial that was very carefully designed to tell us for certain whether endovascular therapy should play a role in the treatment of stroke patients,” said co-investigator Lawrence Wechsler, M.D
., Henry B. Higman Professor and chair, Department of Neurology, Pitt School of Medicine
, and the institute’s founding director. “The UPMC Stroke Institute is a leader in advancing stroke care, and we encourage our patients to take advantage of the opportunity to participate in important clinical trials like this one.”
The study was funded by The Heart and Stroke Foundation of Canada, Alberta Innovates-Health Solutions and Medtronic, along with generous donations to the Calgary Stroke Program.
Watch a video of Dr. Jovin
performing the ET procedure.