Results summary

Read the plain English summary

Results of the SoSTART trial

Why did we do SoSTART?

We wanted to find out whether starting or not starting an anticoagulant drug is better for people who have had a bleed within the skull (known as a “brain haemorrhage”) as well as an irregular heartbeat (known as “atrial fibrillation” or “AF”). Blood-thinning drugs known as “anticoagulants” are taken by people with AF to prevent blood clots forming. Anticoagulants reduce the risk of clots a lot despite increasing the risk of bleeding.

What was SoSTART?

SoSTART was a randomised controlled trial involving 203 survivors of brain haemorrhage who had atrial fibrillation in the UK. SoSTART split the participants into two groups: half were allocated to start an anticoagulant drug, and half were allocated to stay off these drugs. Over the course of 3 years, we kept track of everyone to learn how everyone got on and who had recurrent bleeding or any major event involving the blockage of blood flow, like stroke or heart attack.

What did SoSTART show?

• We had 203 participants in total. 101 participants started taking an anticoagulant drug. 102 participants did not.
• 8 of the 101 participants who took an anticoagulant drug had another brain haemorrhage. 4 had a major event involving blockage of blood flow.
• 4 of the 102 participants who avoided these drugs had another brain haemorrhage. 23 had a major event involving blockage of blood flow.
• We could not prove that starting an anticoagulant drug was not worse than avoiding these drugs.
• However, starting an anticoagulant drug might be better than avoiding these drugs for reducing the overall risk of any major event due to blood vessel blockage or bleeding.
• These promising findings should be investigated in larger trials to be sure about the effects of anticoagulant drugs for people with brain haemorrhage and atrial fibrillation.

What does this mean for patients who have had a brain haemorrhage as well as atrial fibrillation?

The results of SoSTART are not conclusive, although they are encouraging. They do not have immediate implications for whether patients should continue or avoid an anticoagulant drug. Patients could discuss whether they want to make any changes to their medicines with their consultant or GP, who should be aware of these results.