HAMILTON, ON, Aug. 30 /CNW/ - Although warfarin has been, for more than
20 years, the gold standard for reducing stroke in atrial fibrillation, it has
many problems. Warfarin therapy needs to be monitored by blood test
measurements. Many patients cannot take this drug and there is a significant
risk of increased bleeding.
In a major international trial, researchers from McMaster University are
reporting the results of research on a new blood thinner, dabigatran (Pradax
or Pradaxa). In this study, dabigatran has been shown to be superior to
warfarin for the reduction of stroke and also for reducing bleeding
complications, especially bleeding into the brain. The study is to be
presented today at the European Society of Cardiology Congress in Barcelona,
Atrial fibrillation is a common disorder of the heart rhythm that affects
about one percent of the population and up to 10% of people over the age of
80. The major complication of atrial fibrillation is stroke. About one in six
strokes are due to atrial fibrillation. Patients who have atrial fibrillation
have an annual risk of stroke between one to 10%. Blood thinners such as
warfarin are the only way to prevent these strokes.
Several new drugs have been recently studied to see if they could replace
warfarin. None, however, has been satisfactory either because they were not
effective enough; they had too many side effects or they caused too much
The results of the RE-LY study, which compared dabigatran to warfarin in
patients with atrial fibrillation at risk for stroke, clearly show that
dabigatran is superior to warfarin. This is the first time in more than 50
years that a new oral blood thinner has been developed which has been found to
be both safer and more effective than existing therapy.
"Although researchers have been looking for a replacement for warfarin
for several decades, nothing has been successful," said Dr. Stuart Connolly, a
professor of medicine, director of the Division of Cardiology of the Michael
G. DeGroote School of Medicine at McMaster University and one of the leading
investigators of the RE-LY study (Randomized Evaluation of Long-term
The RE-LY study compared two doses of dabigatran with the current
standard therapy, warfarin, in 18,113 patients with atrial fibrillation at
increased risk of stroke. The study included more than 965 centres in 44
countries. Patients were enrolled over a two-year period and then followed for
one further year. The study closed follow-up in March, 2009.
"The importance of the results for the RE-LY study are hard to
overestimate," said Dr. Salim Yusuf, director of the Population Health
Research Institute at McMaster University and Hamilton Health Sciences in
Hamilton. "The results are much better than we had hoped for. It is especially
good that we have two doses of dabigatran that are effective and superior to
warfarin in different ways."
Dr. Connolly predicts that dabigatran will "change the way we treat
patients who have atrial fibrillation at risk of stroke. It will increase the
number of patients who are able to take blood thinners safely and this will in
turn greatly reduce the number of patients with atrial fibrillation suffering
a stroke or dying."
The RE-LY study was designed to evaluate whether either of two doses of
dabigatran was non-inferior to warfarin. In other words, it was designed to
see if either of the two doses of dabigatran was at least as good as warfarin.
The results show, however, that the higher dose, 150 mg twice daily,
significantly reduces the risk of stroke by 34% compared to warfarin, with
similar rates of major bleeding. The lower dose of dabigatran, 110 mg twice
daily, was similar to warfarin in respect to stroke, with significantly less
The study was overseen by researchers from McMaster University; the
Uppsala University in Sweden and the Lankenau Institute for Medical Research
in the U.S. The study was co-ordinated by the Population Health Research
Institute and sponsored by Boehringer-Ingelheim.
For further information:
For further information: and to arrange interviews, please contact:
Susan Emigh, Public Relations, Faculty of Health Sciences, McMaster
University, Phone: (905) 525-9140, ext. 22555, Cell/Mobile: (905) 518-3642,