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RESTART trial results: aspirin gets the green light in stroke due to brain haemorrhage

May 2019: The results of the RESTART trial have found that people who suffer a stroke caused by bleeding in the brain can take common medicines without raising their risk of another stroke.

In the RESTART trial, researchers tracked outcomes from 537 people from across the UK who had suffered a brain haemorrhage while they were taking medicines to stop blood clotting. Patients were randomly assigned to either start taking antiplatelet treatment or avoid it for up to five years.

The team, which was led by Prof Rustam Al-Shahi Salman in CCBS, found that people who took antiplatelet medicines experienced fewer recurrences of brain haemorrhage compared with those who did not take these treatments. Some 12 people suffered a brain bleed while taking the medication compared with 23 people who did not. This may suggest the treatments reduce rather than increase risk of further bleeding in the brain, but further studies are needed to confirm this.

The findings are reassuring for the thousands of people who take the medicines to reduce their risk of heart attack and another common type of stroke caused by blood clots in the brain.

Antiplatelet medicines – which include aspirin and clopidogrel – work by slowing or stopping blood from clotting. It was previously thought that their use might make people with stroke due to brain haemorrhage more likely to suffer another bleed in the brain.

Video abstract

Imaging findings

Around half of the participants underwent an additional brain scan using MRI at the beginning of the study. These scans are often used to check for the presence of tiny blood deposits in the brain, known as microbleeds, which can be a warning sign of future strokes. The researchers found that treatment with antiplatelet medication was not more hazardous for people who already had microbleeds in their brain.

This provides further reassurance that brain haemorrhage survivors can safely continue to take antiplatelet medicines to reduce their risk of future heart attacks or strokes. It also suggests that patients do not need to undergo an MRI scan before starting treatment.


The results of the RESTART trial are reassuring for survivors of brain haemorrhage who need to take antiplatelet medicines to prevent heart attacks and strokes. I am keen to investigate the possibility that these medicines might halve the risk of brain haemorrhage happening again.

Professor Rustam Al-Shahi SalmanCentre for Clinical Brain Sciences; lead on the RESTART trial

The trial is published in The Lancet and The Lancet Neurology. It was funded by the British Heart Foundation.

Related links

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial. The Lancet, 2019. DOI: 10.1016/S0140-6736(19)30840-2

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: sub-group analyses of the RESTART randomised, open-label trial. The Lancet Neurology, 2019.  DOI: 10.1016/S1474-4422(19)30184-X  

RESTART trial website

Professor Rustam Al-Shahi Salman's profile

Research to Understand Stroke due to Haemorrhage

Brain vascular disease research at the Centre for Clinical Brain Sciences

Edinburgh Imaging

Edinburgh Clinical Trials Unit