graphic illustration of a doctor pointing at a holographic image on the brain

Why is PRESTIGE-AF needed?

PRESTIGE-AF aims to resolve an area of medical uncertainty

Atrial fibrillation is the most common form of irregular heart rhythm. In people with atrial fibrillation, blood clots often form in the heart, which can travel to the brain. Blockage of brain arteries by these clots is a major cause of stroke. This type of stroke is called an ischaemic stroke and approximately 15% of all ischaemic strokes are caused by atrial fibrillation.

People with atrial fibrillation are often prescribed a medication called an anticoagulant, which makes it less likely for blood clots to form and thus can prevent ischaemic strokes.

However, anticoagulants also increase the risk of bleeding, so they are not suitable for everyone.

Some people who have AF have had a different type of stroke which is caused by bleeding in the brain – an intracerebral haemorrhage (ICH). These people are at increased risk of suffering both an ischaemic stroke (due to atrial fibrillation) and another ICH.

It is not known whether it is best for these people to take an anticoagulant medication or not, as previous research studies did not include this group of people.

Stroke is one of the largest public health challenges around the world, being the most common cause of adult-acquired disability, the second leading cause of death globally, and the second most frequent cause of dementia. In addition, its impact is expected to further increase in the coming decades due to the ageing population, so understanding how to prevent further stroke in all groups is vital.

The PRESTIGE-AF project aims to answer the question of whether people with ICH and atrial fibrillation should take an anticoagulant medication or if it is better for them to avoid it.

Learn more about the PRESTIGE-AF trial and sub-studies

Key definitions


A medical condition that happens when the blood supply to part of the brain is cut off, usually from bleeding or a blood clot in the brain.

Intracerebral haemorrhage:

A type of stroke caused by bleeding in the brain. Often shortened to “ICH”.

Ischaemic stroke:

A type of stroke caused by a blood clot or blockage in the brain.

Heart arrhythmia:

An irregular heartbeat.

Atrial fibrillation:

The most common form of heart arrhythmia. Atrial fibrillation increases the likelihood of experiencing an ischaemic stroke. Often shortened to “AF”.


A medication that makes it less likely for blood clots to form and thus is used for ischaemic stroke prevention. However, patients taking anticoagulants have a higher risk of bleeding including intracerebral haemorrhage.