A new anticoagulant is superior to warfarin for preventing stroke and systemic embolism in patients with atrial fibrillation, a randomised controlled trial has found.
The ARISTOTLE trial compared the use 5mg dose of apixaban, a new oral direct factor Xa inhibitor, with warfarin with an INR target between 2.0 and 3.0, in 18,000, patients followed-up for a median of 1.8 years.
Apixaban resulted in an additional 21% relative reduction in stroke and systemic embolism and a 31% relative reduction in major bleeding, as well as an 11% relative reduction in overall mortality. Haemorrhagic stroke was reduced by 49%.
For every 1,000 patients treated with apixaban, eight patients were prevented from dying, six from having a stroke and 15 from major bleeding. Apixaban also prevented four patients from haemorrhagic strokes and two patients from ischaemic or other kinds of strokes.
Study leader Dr Christopher Granger, professor of medicine at Duke University in North Carolina, concluded: ‘Warfarin is highly effective but is associated with a variable response. The alternative treatment regimen with apixaban, which does not require anticoagulation monitoring, not only is more effective but also accomplishes this goal at a substantially lower risk of bleeding with lower discontinuation rates.'
Dr George Kassianos, a GP in Bracknell, Berkshire, and a fellow of the European Society of Cardiology, said: 'There is a need to move away from warfarin and the need for INR checks to drugs that do not require such a close supervision, provided the anticoagulation benefit is not lost.'
'The Apixaban trial has shown some remarkable results as regards to rate of bleeding, death, and haemorrhagic stroke compared to warfarin.'
But he added: 'These new drugs offer real advantages over warfarin but their purchasing price is much higher. We need a good evaluation of total cost as a matter of urgency.'
ESC 2011 and NEJM 2011, published 28 August.