Sunnybrook leads innovative Canadian stroke trial targeting brain hemorrhage
Canadian
stroke researchers have teamed up to launch a multisite clinical trial of an
image-guided treatment strategy for a serious form of stroke caused by bleeding
in the brain. If proven successful, their protocol could lead to the first
effective emergency treatment for intracerebral hemorrhage, the deadliest and
most disabling type of stroke.
"We are trying to find a way to stop bleeding in the brain during the critical
first few hours of a hemorrhagic stroke. With no approved emergency treatments
for patients with intracerebral hemorrhage, there is a pressing need for this
kind of research," said Dr. David Gladstone, principal investigator of the
SPOTLIGHT trial and scientist in the Brain Sciences Research Program at Sunnybrook
Research Institute in Toronto. "These are life-threatening hemorrhages, with
half of patients dying within days," added Gladstone, who presented the study
plans at the Canadian Stroke Congress on October 3, 2011.
The researchers will test a strategy that uses advanced imaging technology to
identify the stroke patients at highest risk of further bleeding in the brain
as soon as they get to the emergency department. These patients will then be
randomly assigned to either a treatment or control group. Patients in the
treatment group will get an injection of recombinant activated coagulation
Factor VII, a
drug that has shown promise to treat bleeding. Researchers will evaluate if
this novel pairing of imaging and therapy can improve outcomes in these
high-risk patients.
The trial will test if this treatment protocol can be
administered rapidly and safely to stroke patients in the emergency department,
and whether it can effectively reduce bleeding in the brain. "The hope is that treatment to reduce brain bleeding, if
administered quickly enough and to the right patients, can translate into
improved recovery and reduced disability," said Gladstone, who is also director of the Regional Stroke Prevention
Clinic at Sunnybrook Health Sciences Centre and assistant professor in the department
of medicine at the University of Toronto.
The SPOTLIGHT trial builds upon the
imaging discovery of the "spot sign," described by Sunnybrook's Dr. Richard
Aviv and colleagues, and further characterized by Dr. Andrew Demchuk, both of
whom are co-principal investigators on the trial. The spot sign is seen using
computed tomography (CT) angiography, a technology that can visualize bleeding
blood vessels in the brain.
"The spot sign
method has become the most rapid, accurate and reliable way to predict which
patients are actively bleeding and at highest risk of worsening due to
hemorrhage expansion," said Aviv, who is a
neuroradiologist at Sunnybrook and researcher at SRI. "This imaging advance is
going to significantly improve patient selection for clinical trials," said Demchuk, director of the Calgary Stroke Program and
professor at the University of Calgary.
Recombinant
Factor VIIa is used for other life-threatening bleeding conditions, but is
still under study as a therapy for brain hemorrhage. Although it has shown
promise in treating this condition, a major limitation of previous trials is
that they have not focused on the highest-risk patients, the active bleeders,
who are the ones most likely to benefit from the therapy. This trial is
designed to overcome that limitation. It is the first Canadian study to test
the therapy in patients specifically selected using CT angiography because they
have the spot sign.
Looking ahead, the hope is that this therapy could become a first-line
treatment in the future, said Gladstone. "For years, intracerebral hemorrhage
has been considered an untreatable type of stroke, with a dismal prognosis for
many patients. If this new image-guided approach proves successful, then it
could revolutionize how such patients are treated worldwide," he said.
The randomized controlled trial received Health
Canada approval and was awarded a top-rated research grant from the Canadian
Institutes of Health Research (CIHR). The study, coordinated at the Li Ka Shing
Knowledge Institute of St. Michael's Hospital in Toronto, will recruit patients
from hospitals across Canada that are members of the Canadian Stroke
Consortium, a network of leading stroke centres.
The SPOTLIGHT trial is funded by CIHR, the Ontario
Stroke Network and the Ontario Ministry of Research and Innovation.