Investigators at the Mater Misericordiae University Hospital and University College Dublin have made a discovery that may significantly reduce the number of patients who experience a recurrent stroke.
The research, funded by the Irish Heart Foundation and published in the early-view edition of the Annals of Neurology, showed that plaque inflammation in the carotid artery predicts early stroke recurrence. This discovery means that patients who are at very high risk of a second — and often far more debilitating — stroke might be identified through diagnostic imaging tests and receive intensive treatment, such as surgery, to reduce or remove excess carotid plaque.
The findings are based on a study involving 60 patients, all of whom had suffered a mini-stroke. A diagnostic imaging test to measure plaque inflammation was carried out on each patient within 14 days of the initial mini-stroke. Follow-up measurements and analysis were carried out for a period of 90 days. Of the 60 patients who participated, 13 had a recurrent stroke. The research team found that there was a very significant association between plaque inflammation and the 13 patients who had a recurrent stroke.
Prof Peter Kelly, Principal Investigator on the project, Associate Professor of Neurology at UCD and Consultant Neurologist at the Mater University Hospital, said the findings could have important implications for the health and prospects of patients who present following a minor stroke.
“At the moment, 20 out of every 100 patients who suffer a mini-stroke will have another stroke within 90 days. The risk is front-loaded in the week immediately following the mini-stroke and a recurrence is usually far more profound and debilitating. This research describes a way to determine those patients who are most at risk by measuring the level of plaque inflammation in the carotid artery. We used a diagnostic imaging device known as PET-CT to gauge levels of inflammation, which then shows up on the scan as a bright spot. We were able to set a threshold whereby the level of brightness corresponds to the highest stroke risk — thereby predicting the likelihood of a recurrent stroke for high-risk patients,” said Prof Kelly.
Current international guidelines recommend that patients who present following a mini-stroke routinely undergo a number of diagnostic tests, one of which involves a carotid ultrasound to determine the extent to which the carotid artery has narrowed.
However, this approach is limited in its effectiveness. The findings from Prof Kelly and his team point to plaque inflammation — not just narrowing — as the primary predictor of recurrent stroke.
“This could fundamentally change the way in which we target and treat patients who present following a mini-stroke. It means that we may be able to significantly reduce the number of people who suffer a second stroke during the high risk period by identifying and treating them more quickly. Further down the line, we can use these findings in trials by inventing drugs that attack and reduce levels of inflammation in the carotid artery,” added Prof Kelly.
Ann. Neurol. First published online: 29 Mar 2012, DOI: 10.1002/ana.23553.