Carotid Artery MRI Helps Predict Cardiovascular Events

MRI can help identify carotid artery plaque, and accurately predict future cardiovascular events, according to a study published in the journal Radiology.

A team of U.S. and Canadian researchers sought to determine if carotid plaque morphology and composition with MRI imaging could be used to identify asymptomatic patients who were at risk of cardiovascular events such as strokes or heart attacks.

A study group comprising 936 asymptomatic subjects, who were part of the Multi-Ethnic Study of Atherosclerosis (MESA), underwent carotid artery ultrasound imaging for carotid wall thickness assessment and MR imaging for definition of carotid plaque composition and remodeling index. The incidents of cardiovascular events included myocardial infarction, resuscitated cardiac arrest, angina, stroke, and death, over an average of 5.5 years.

The results showed that MR imaging displayed lipid core present in 19.1 percent of the subjects, and calcium and ulceration were seen in 2.4 percent and 0.2 percent of the studies, respectively.

Cardiovascular events occurred in 59 study participants (6 percent):

• 19 experienced myocardial infarction;
• 22 experienced angina (21 definite angina, 1 probable angina followed by revascularization);
• 4 died from coronary heart disease;
• 1 participant experienced resuscitated cardiac arrest;
• 9 experienced cerebrovascular disease; and
• 4 died from cerebrovascular disease.

"The primary factors that predicted future risk were measures of vessel wall thickness in combination with the presence or absence of a lipid core," co-author David A. Bluemke, MD, PhD, said in a release. "The presence of a lipid core was 50 percent more common in people who had subsequent events."

Adding the sequences for plaque composition to existing carotid MRI angiography protocols could be easily done, noted Bluemke. "Carotid MRI has significant advantages," he said. "The results are more reproducible than those of ultrasound."