McMaster University

McMaster University

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McMaster research showcased at international cardiology conference

Published: August 31, 2010
Sanjit Jolly
Sanjit Jolly, an assistant professor of medicine in the Michael G. DeGroote School of Medicine
Stuart Connolly
Stuart Connolly, a professor of medicine in the Michael G. DeGroote School of Medicine

A drug trial led by McMaster University investigators has been stopped after overwhelming evidence that a new oral blood thinner prevents stroke in patients with atrial fibrillation who are unsuitable for the conventional treatment of warfarin.

The decision to halt the AVERROES (Apixaban Versus Acetylsalicylic Acid to Prevent Strokes) study came after repeated review and careful consideration of all efficacy and safety data.

The McMaster study leaders, Stuart Connolly, principal investigator; Salim Yusuf, chair of the steering committee, and John Eikelboom, project officer, have accepted this recommendation, as have the study sponsors, Bristol-Myers Squibb and Pfizer.

The AVERROES findings were presented by Connolly at the annual European Society of Cardiology Congress in Stockholm, Sweden, on August 31.

The AVERROES study enrolled 5,600 patients with atrial fibrillation at risk for stroke who were unsuitable for treatment with warfarin. These patients were randomized, double-blind, to receive either apixaban or the standard therapy, Aspirin. 

The data monitoring committee observed a relative risk reduction for stroke and systemic embolism of more than 50 per cent, which was highly statistically significant and met the highly conservative monitoring boundaries of the AVERROES study.  There was only a modest increase in major hemorrhage that was not statistically significant.

"The results of AVERROES are truly impressive," said Connolly, a professor of medicine at the Michael G. DeGroote School of Medicine. "The reduction in stroke and systemic embolism is very important and the increased risk of hemorrhage is small.  It appears that apixaban will be an excellent treatment for the many patients with atrial fibrillation who are unsuitable for warfarin. These findings will reduce the burden of stroke in society." 

Atrial fibrillation is a common heart rhythm disorder, in which the upper chamber of the heart beats improperly. Patients with atrial fibrillation have increased risk of stroke due to the formation of blood clots in the upper chamber of the heart. 

The AVERROES study was performed globally in more than 40 countries. The study was coordinated by the Population Health Research Institute (PHRI) at McMaster University and at Hamilton Health Sciences.

Research findings from two other McMaster-led studies were also presented at the European Society of Cardiology Congress:

Guillaume Paré, an assistant professor of pathology and molecular medicine, presented new findings from the trials called CURE (Clopidogrel in Unstable Angina to Prevent Recurrent Ischemic Events) and ACTIVE (Atrial Fibrillation Clopidogrel Trial with Irbesartan for the Prevention of Vascular Events) that contradict earlier reports that people with a certain genetic makeup don’t benefit from the blood-thinner clopidogrel, also known as Plavix.

"We found the previously reported genetic variants had no effect at all (for patients) in either the CURE or ACTIVE trials," Paré said.

The findings were presented on August 29, and simultaneously published online in the New England Journal of Medicine.

Sanjit Jolly, an assistant professor of medicine, presented results from a landmark study that found lower doses of a blood thinner called unfractionated heparin (UFH) during angioplasty did not reduce bleeding or vascular complications compared to standard dose UFH in patients initially treated with a blood thinner, fondaparinux.

The results of the FUTURA-OASIS 8 (Fondaparinux with UnfracTionated heparin dUring Revascularisation in Acute coronary syndromes) trial were presented on August 31 and also published simultaneously in the Journal of the American Medical Association (JAMA).

The CURE and ACTIVE trials were sponsored by Sanofi-Aventis and Bristol-Myers Squibb, and the FUTURA-OASIS 8 trial was supported by GlaxoSmithKline. All research was conducted independently by the Population Health Research Institute.


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