People with irregular heartbeats who have a stroke are 35% less likely to have a second stroke if they are given blood thinners earlier than currently recommended, research has found.
There is more than 1.6 million people in the UK with atrial fibrillation – an irregular heartbeat. The condition can lead to a clot forming in the heart, which can travel to the brain, block the blood supply and cause a stroke.
In the United Kingdom, more than 100,000 people have a stroke every year, and atrial fibrillation patients are five times more likely to have a stroke than those without the condition.
People with atrial fibrillation who have had a stroke are also at increased risk of having another, but this risk can be reduced by taking anticoagulants.
However, anticoagulants can cause brain bleeding. UK guidelines suggest that patients with irregular heartbeats who have had a moderate or severe stroke should wait at least five days before starting blood thinners.
Now two new studies, presented at the World Stroke Congress 2024, suggests that people with atrial fibrillation who have a stroke and take blood thinners earlier than currently recommended are not only less likely to have a second stroke, but have no increased risk of a brain bleed than those what it takes later. .
An international team of researchers conducted a meta-analysis of four randomized controlled trials that looked at the safety and effectiveness of early initiation of anticoagulants, compared with later, in people with acute stroke and atrial fibrillation.
The academics compared more than 5,000 patients who were given blood thinners within four days of a stroke with those who started anticoagulants on the fifth day or later. They found that 2.12% of patients given anticoagulants within four days had another stroke within 30 days, compared with 3.02% of those who started them later – a difference of 35%.
A second study presented at the conference, funded by the British Heart Foundation and published in the Lancetfound that giving anticoagulants within four days of a stroke—rather than delaying treatment—did not increase the risk of a brain bleed, even for those who had a more severe stroke.
The team analyzed data from 3,621 patients with atrial fibrillation who had a stroke between 2019 and 2024, in 100 UK hospitals. Half of the participants started anticoagulant treatment within four days of their stroke (early), and the other half started treatment seven to 14 days after having a stroke (delayed). Early treatment was found to be just as effective as delayed treatment and did not increase the risk of bleeding in the brain.
David Werring, a professor of clinical neurology at University College London and a lead author of both studies, said: “It’s not like a magic bullet, but at a population level it’s really important. If we could give anticoagulants to 20,000 people a year earlier – the approximate number of people with atrial fibrillation who have a stroke in the UK each year – it means we could potentially stop up to 200 strokes. And importantly, there appears to be no increased risk of brain bleeding if you start this treatment earlier.”
Commenting on the findings, Prof Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said: “These results could be transformative, making the case for earlier treatment that could help more people with atrial fibrillation avoid another stroke to avoid, and the associated complications.”
