Precise measurements of coronary artery plaque using cardiac CT may enhance risk prediction in patients with symptomatic coronary artery disease, a study has found.

Borek Foldyna, MD, a cardiovascular radiologist at Massachusetts General Hospital in Boston, and his colleagues, used data from more than 4200 patients who underwent coronary CT angiography as part of the PROMISE trial.

They used advanced imaging to measure plaque in the coronary arteries and evaluated whether these quantitative measurements predict future cardiovascular events. The work was published in JAMA Cardiology.

The researchers found that the total amount of plaque — both volume and burden, and especially noncalcified plaque — predicts cardiovascular events independent of traditional risk factors as well as clinical variables such as calcium score and obstructive stenosis.

“The quantitative measurement has prognostic value beyond all of those other measures,” Foldyna said.

For example, total plaque volume over 87 mm³ or total plaque burden greater than 35% more than doubled the risk for the composite endpoint of major adverse cardiac events, which included death, nonfatal myocardial infarction, or hospitalization for unstable angina, independent of clinical risk factors and traditional qualitative coronary CT angiography measures.

“Even relatively small amounts of plaque carried a meaningful risk in our population,” he said.

Foldyna said that quantitative plaque assessment could help identify patients who need more aggressive treatment, guide treatment decisions, and serve as an objective way to monitor response to therapy over time, such as tracking how well statins are able to reduce noncalcified plaque.

But Armin Zadeh, MD, director of Cardiac Computed Tomography at Johns Hopkins Hospital in Baltimore, questioned whether this expensive new technique is ready for widespread clinical use.

“This study confirms that coronary plaque is a main predictor of major adverse cardiac events; however, it remains unclear whether fully quantifying atheroma burden is more effective than standard coronary artery assessments such as calcium scoring or semi-quantitative plaque evaluation for patient management,” he said. “This technology is the future, but we are not quite there yet.”

Foldyna and Zadeh reported having no relevant financial relationships. Zadeh receives research support from Canon Medical Systems.

Brian Owens is a freelance journalist based in New Brunswick, Canada.