Plaque Characteristics Independently Tied To Cardiovascular Events

In addition to traditional cardiovascular risk factors, inclusion of plaque characteristics beyond thickness alone can enhance prediction of cardiovascular disease (CVD) events.

"We used high-resolution MRI to image atherosclerotic plaques in the carotid arteries of participants without prior evidence for cardiovascular disease in the Atherosclerotic Risk in Communities (ARIC) study," explained Dr. Bruce A. Wasserman of Johns Hopkins School of Medicine, in Baltimore, Maryland.

"Those participants found to have plaque containing a lipid core were at a higher risk for future cardiovascular events, which included coronary heart disease events and ischemic strokes," he told Reuters Health by email.

Dr. Wasserman and colleagues note in their paper in JAMA Cardiology that despite some positive findings, it remains unclear "whether measures of MRI plaque characteristics are associated with cardiovascular events independent of measures of plaque burden at the population level."

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To investigate, they followed 1,256 participants in the ARIC MRI substudy for a median of 10.5 years. All had complete data and MRI showed that a lipid core was present in 403 (32%) and calcification was detected in 376 (30%),

Overall, 172 participants (14%) experienced a total of 183 incident cardiovascular events. These comprised 125 coronary-heart-disease events, among them 72 myocardial infarctions, as well as 58 ischemic strokes.

Comparison of carotid-artery plaques between patients with and without incident CVD events showed a significantly higher normalized wall index. This was also the case for maximum carotid-artery wall thickness, maximum carotid-artery stenosis, and when present, greater lipid-core volume.

As opposed to presence of a lipid core, calcification was not independently associated with incident CVD events. After adjustment for traditional risk factors and carotid-artery wall thickness, lipid-core presence was associated with a hazard ratio of 2.48 (P=0.003).

The finding "offers insight into identifying CVD risk in asymptomatic individuals in a community-based population beyond what can be achieved using traditional risk factors and plaque thickness," said Dr. Wassermann.

The study did not have commercial funding.

—David Douglas

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