One of the dangerous things about strokes is they come on suddenly with few symptoms, until the person is actually having the stroke.
High blood pressure is one risk factor, but a new test may provide an early warning of stroke risk and save lives, researchers say.
A new study suggests a simple ultrasound test may help to identify people at high risk of stroke who have a condition called asymptomatic carotid stenosis, a narrowing of the carotid artery found in the neck. People who have this condition display almost no symptoms.
“There is debate over how to best treat people with asymptomatic carotid stenosis,” said study author Raffi Topakian, MD, of the Academic Teaching Hospital Wagner-Jauregg in Linz, Austria. “A procedure called carotid endarterectomy can reduce the risk of stroke, but there are risks and costs involved with the surgery. Identifying people with asymptomatic carotid stenosis who are at higher risk of stroke would help determine whether carotid endarterectomy is needed.”
The surgery removes the plaque buildup in the carotid artery, which is the main artery from the heart to the brain.
More fat than regular plaque
For the study, 435 people with asymptomatic carotid stenosis were followed for two years. They underwent ultrasound of the carotid artery and of blood vessels in the brain to determine whether two markers for high risk of stroke were present. The markers were signs of blood clots passing into the brain, and a type of carotid plaque called echolucent plaque, which has a higher fat content than other plaque.
Of the participants, 164 people had echolucent plaque, or 38 percent, and 73 people, or 17 percent, had at least one sign of a blood clot. Six percent, or 27 people, had both markers. During the study, 10 people had strokes and 20 people had transient ischemic attacks, or mini-strokes.
Six times the risk
The study found that people with the plaque in their carotid artery were more than six times more likely to have a stroke than those people without the plaque. People who had the plaque and signs of blood clots were more than 10 times more likely to have a stroke than those without both markers. The results remained the same regardless of high blood pressure, diabetes, smoking and vascular disease.
So where does the test come in? Topakian says with more study, researchers should be able to develop a simple and reliable method for predicting future stroke in people with asymptomatic carotid stenosis and help to determine the best way to treat people with the disorder.
The test, he said, should be able to identify a high risk group as well as a low risk group.