Start or STop Anticoagulants Randomised Trial (SoSTART)

Primary research question: For adults surviving spontaneous (non-traumatic) symptomatic intracranial haemorrhage with persistent/paroxysmal atrial fibrillation/flutter (AF), does starting full treatment dose oral anticoagulation (OAC) result in a beneficial net reduction of all serious vascular events compared with not starting OAC?

Trial design: Investigator-led, multicentre, randomised, open, assessor-masked, parallel group, clinical trial of investigational medicinal product (CTIMP) prescribing strategies. Investigators plan for a pilot phase, followed by a safety phase.

Bleeding within the skull, also known as brain haemorrhage, affects 3 million people in the world each year.

One in five people who survive brain haemorrhage have an irregular heart rhythm called 'atrial fibrillation', which puts them at risk of stroke and other blood clots.

Blood-thinning medicines, known as 'anticoagulant' drugs, are used in everyday clinical practice to protect people with atrial fibrillation from developing blood clots. However, these drugs also increase the risk of bleeding and are usually stopped when the brain haemorrhage occurs.

But when patients recover from brain haemorrhage, they and their doctors are often uncertain about whether to start or stop these drugs to prevent further clots occurring, or whether to avoid them in case they increase the risk of brain haemorrhage happening again.

Investigators want to find out whether starting or not starting an anticoagulant drugs is better for those patients.

A network of hospital doctors, nurses, and other staff will identify people who survive brain haemorrhage and have atrial fibrillation. If a patient and their doctor are uncertain about whether to start an anticoagulant drug, they may invite the patient to participate.

In the pilot phase, investigators aim to recruit at least 60 participants to determine the feasibility of recruiting the target sample size of at least 190 participants in the safety phase of the trial.

Investigators will follow-up all participants for at least one year to determine whether prescribing an anticoagulant drug reduces the occurrence of all serious vascular events like heart attack, stroke compared with a policy of avoiding oral anticoagulant.

Eligibility Criteria:
Inclusion Criteria:

1. Patient age ≥18 years
2. Symptomatic intracranial haemorrhage (i.e. intracerebral haemorrhage, non-aneurysmal subarachnoid haemorrhage,intraventricular haemorrhage, or subduralhaemorrhage)

   * Not attributable to a known underlying intracranial aneurysm, arteriovenous malformation, cerebral cavernous malformation, dural arteriovenous fistula, intracranial venous thrombosis
   * Not attributable to known head injury, based on:
   * a history from the patient/witness of spontaneous symptom onset without preceding head trauma (head trauma occurring after symptom onset is permissible)
   * brain imaging appearances consistent with spontaneous intracranial haemorrhage (which may be accompanied by the brain/bone/soft tissue appearances of trauma occurring subsequently)
3. Atrial fibrillation/flutter (persistent or paroxysmal) with a CHA2DS2-VASc score ≥2
4. If included in the brain magnetic resonance imaging (MRI) sub-study, the scan must be done after symptomatic intracranial haemorrhage and before randomisation

Exclusion Criteria:

1. Symptomatic intracranial haemorrhage within the last 24 hours (when the risk of haemorrhage expansion/growth is greatest)
2. Symptomatic intracranial haemorrhage is exclusively due to trauma or haemorrhagic transformation of ischaemic stroke
3. Prosthetic mechanical heart valve or severe (haemodynamically significant) native valve disease
4. Left atrial appendage occlusion for prevention of systemic embolism in AF done in the past, or intended to be performed
5. Intention to start antiplatelet drug(s) if randomised to start full dose OAC
6. Intention to start OAC or parenteral anticoagulation
7. Intention to implement the allocated treatment strategy for \<1 year
8. Patient or their doctor is certain about whether to start or avoid full dose OAC
9. Brain imaging that first diagnosed the intracranial haemorrhage is not available
10. Patient is not registered with a general practitioner
11. Patient is pregnant, breastfeeding, or of childbearing age and not taking contraception
12. Patient and carer unable to understand spoken or written English
13. Contraindications to any of the IMPs, other than recent intracranial haemorrhage
14. Contraindication to MRI (brain MRI sub-study)
15. Life expectancy less than one year
16. Previously randomised in SoSTART