WHY IS OPTIMAS AN IMPORTANT TRIAL?
The OPTIMAS trial aims to establish the best time to start blood-thinning medication after stroke, an important unanswered question in neurology and stroke medicine. Each year, around 30,000 people in the United Kingdom suffer a stroke due to atrial fibrillation, an abnormal heart rhythm which causes up to a quarter of all strokes. For most of these people, anticoagulant medication is the best way to prevent a further stroke, but how soon after a stroke it should be started is unknown.
Historically, taking anticoagulant medication early after stroke has been considered to increase the risk of potentially harmful intracranial bleeding. For this reason, many clinicians delay anticoagulation for up to two weeks after stroke. However, the risk of recurrent ischaemic stroke in this time is 0.5%/day. Therefore, hundreds of people each year in the United Kingdom alone may suffer a recurrent stroke while waiting to start anticoagulation. If anticoagulation could be started earlier, safely, many of these strokes could be prevented.
Although the practice of delayed anticoagulation is supported by several current guidelines, these are based largely on historical and observational data in patients treated with Warfarin, an older anticoagulant with a much higher risk of causing bleeding than the direct oral anticoagulants (DOACs) increasingly used in contemporary clinical practice. More recent studies suggest that early DOAC use is associated with a low risk of symptomatic and asymptomatic intracranial haemorrhage, whereas delayed DOAC initiation is associated with an increased risk of recurrent ischaemic stroke.
These findings suggest that early DOAC use may be safe and effective; however, a large randomised controlled trial comparing early to later DOAC administration in patients with ischaemic stroke and atrial fibrillation is needed definitively to answer this question. The OPTIMAS trial aims to achieve this, and, in doing so, to improve medical care for this large group of stroke survivors.
The following papers provide further information on why this research is so important:
Timing of anticoagulation after recent ischaemic stroke in patients with atrial fibrillation (2019)