Carotid Artery Disease after Stroke. V1
Research type
Research Study
Full title
Carotid Artery Disease after Stroke
IRAS ID
157417
Contact name
Charles McCollum
Contact email
Sponsor organisation
University Hospital of South Manchester
Research summary
Summary of Research
Stroke is the leading cause of disability in the UK with 152 000 new strokes/year. In 2010 it was the fourth largest cause of death, causing almost 50,000. Carotid artery disease (disease of the main artery supplying the brain) accounts for 30% of all strokes. At present, the degree of Carotid artery stenosis (narrowing) determines the need for surgery. Carotid artery narrowing is caused by accumulation of lipid, protein and cholesterol (atherosclerosis). This produces a plaque. Carotid artery surgery (carotid endarterectomy) removes this plaque therefore reducing the stroke risk. Studies have shown that the severity of carotid narrowing is a poor predictor of stroke risk. Many patients without symptoms have severe carotid artery narrowing and many stroke victims have only mild to moderate narrowing. It is therefore postulated that the volume of the plaque and other characteristics may be of greater significance than the degree of narrowing.
We performed a pilot study of 200 patients highlighting a potential link between plaque volume and stroke risk. The plaque volume in patients undergoing carotid surgery within four weeks of symptoms was almost double that of asymptomatic patients. Plaque volume also fell rapidly within four weeks of symptoms and continued falling for eight weeks.This study aims to measure the change in plaque volume over a 12 week period in patients who have suffered a recent stroke.
All patients admitted to Wythenshawe hospital who have suffered a stroke due to carotid artery disease will be given the opportunity to partake in this study. They will have their carotid artery disease evaluated by contrast enhanced 3-dimensional duplex (ultrasound). They will have a blood test for aspirin resistance and trans-cranial Doppler (sound of blood flow through a vessel).
This study will prove that carotid artery plaque volume is a more sensitive marker of stroke risk.
Summary of Results
Background
One third of ischaemic strokes are caused by a fatty build up (atherosclerotic plaque) on the wall of the blood vessel supplying the brain (carotid artery). This process takes years to develop but is detectable, by ultrasound, prior to a Stroke or mini stroke. Currently the degree of narrowing (stenosis) of the artery is used to determine treatment, but this relates poorly to how stroke is caused. Measuring the volume of disease in the artery is felt to be more accurate at predicting stroke than the stenosis. Carotid Plaque Volume (CPV) has been shown to be better at predicting stroke than stenosis and can be accurately measured by a simple 3D ultrasound scan. We need to identify the highest risk plaques before stroke occurs. The first step to this goal is identifying the high risk features of plaque in the recently symptomatic individual and see how it changes over time.Methods
We intended to recruit 15 individuals to have five 3D ultrasound scans over 12 weeks following stroke. From the scans we could measure the plaque volume and look at other features of the disease.Results
Despite intensive efforts, we were unable to recruit to this study as the standard of care is to receive surgery within 2 weeks to clean the disease out of the artery. From screening data we can see that only 0.6% of those screened for inclusion, were eligible. Individuals who refused surgery or were considered too unwell for surgery were also too unwell to participate in research.Conclusion
A very small proportion of those screened were eligible for study inclusion effectively making the study design unfeasible. Although this study posed an important question, it is uncertain how it can ever be addressed using the proposed study design and when considering current management protocols for symptomatic carotid disease.REC name
Wales REC 4
REC reference
14/WA/1093
Date of REC Opinion
7 Aug 2014
REC opinion
Favourable Opinion