Study leaders Donald Singer, a professor at Warwick Medical School, and Chris Imray, a professor from University Hospitals Coventry and Warwickshire, said their study used ultrasound scanning to look at patients with carotid artery disease, one of the major causes of stroke.
Clots can form on diseased carotid arteries in the neck and small parts of these clots can released to form microemboli, which can travel to block key brain arteries and lead to weakness, disturbed speech, loss of vision and other serious stroke syndromes, the researchers said.
Standard anti-platelet drugs such as aspirin may not prevent the formation of harmful microemboli, the researchers said.
The scanning could be used to find patients at very high risk of stroke because microemboli have formed despite prior anti-platelet drugs. Using scanning, the team has found that tirofiban, another anti-platelet drug designed to inhibit the formation of blood clots, can suppress microemboli where previous treatment such as aspirin was ineffective.
"These findings show that the choice of rescue medicine is very important when carotid patients develop microemboli despite previous treatment with powerful anti-platelet drugs such as aspirin. We now need to go on to further studies of anti-microemboli rescue treatments, to aim for the right balance between protection and risk for our patients."
The findings were published in the journal Stroke.