Predicting Heart Attacks

18F sodium fluoride tracer shows active calcium build up that could lead to heart attack

(RxWiki News) The ability to predict and prevent heart attacks is considered the holy grail in cardiology. Scientists may not be there yet, but they've taken another bold step toward prediction in a new clinical trial.

British researchers have found that injecting a tracer prior to PET and CT scanning aids in helping to identify active calcium build up that could lead to a heart attack.

Marc Dweck, MD, lead author and a British Heart Foundation Clinical Research Fellow at the University of Edinburgh, noted that predicting heart attacks is very difficult and current methods are "good but not perfect."

Dr. Dweck said the new technique has promise for improving heart attack prediction, though further work is needed before it could become routine in clinical practice.

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

During the study, researchers from the University of Edinburgh and the University of Cambridge assigned a CT calcium score, a measure of the amount of hardened plaque in coronary arteries, to 119 participants.

The standard test can predict coronary heart disease, but cannot distinguish between plaque that has recently formed compared to calcium that has been present in arteries for months or years.

The patients, including those without calcified plaque, were injected with two tracers, or molecules that appear on imaging scans and can be used to track substances in the body. One of the tracers injected was 18F-sodium fluoride (18F-NaF), a molecule only absorbed by cells when active calcification is happening.

Researchers used both CT and PET scans to determine whether they could identify active calcification because this can put patients at greater risk than plaque that has been in arteries for years, They found through scans that increased 18F-NaF activity was observed in specific coronary artery plaques in patients with numerous other high-risk markers of cardiovascular disease.

"For decades cardiologists have been looking for ways to detect the high-risk plaques found in coronary arteries that could rupture to cause a heart attack, but it's been difficult to develop a suitable imaging test that can focus in on these small vessels," said Dr. Shannon Amoils, research advisor at the British Heart Foundation.

"This research is a technical tour de force as it allows us to assess active calcification happening right in the problem area – inside the wall of the coronary arteries and this active calcification may correlate with a higher risk of a heart attack."

The study was recently published in the Journal of the American College of Cardiology.

Review Date: 
April 24, 2012