Combined medical scans used to predict heart attack risk

Positron emission tomography (PET) technology combined with computed tomography (CT) technology could help doctors to predict a patient's risk of having a heart attack with more accuracy, according to a study published this week in the Journal of the American College of Cardiology.

The key to the combination, according to lead study author Marc Dweck, M.D., and his colleagues, is differentiating between older calcified plaque in a patient's coronary arteries and plaque in the process of calcifying. A CT scan can show the overall amount of hardened plaque in a patient, but can't distinguish the old from the new.

A PET scan, with the help of a specific tracer--a set of molecules that appears on certain imaging scans--can make that distinction, though. According to the researchers, 18F-sodium fluoride is a molecule that sticks to cells where active calcification is present. After running an 18F-sodium fluoride tracer through a patient, a PET scan can display the results.

Dweck and his team found increased 18F-sodium fluoride activity occurring in the coronary artery plaques for patients considered more high risk with regard to cardiovascular disease. Overall, 119 volunteers participated in the study.

According to Dweck, the combo-image scan method has potential, but isn't ready for prime time just yet.

"If we can identify patients at high risk of a heart attack earlier," he said in an announcement, "we can then use intensive drug treatments, and perhaps procedures such as stents, to reduce the chances of them having a heart attack."

To learn more:
- here's the study's abstract
- read this announcement from the University of Edinburgh