The skinny on cardiac fat

skinny on cardiac fat

“Doctor, does this CT scan make my heart look fat?”

If the answer is yes, you may be a candidate for a nuclear stress test, which indicates how well the heart works during physical activity and
at rest.

A recent study shows that patients with more epicardial adipose tissue, that is, a layer of fat around the heart, tend to have the types of atherosclerotic plaques that cardiologists deem most dangerous. These plaques fall into the non-calcified category.

Fortunately, this type of heart fat tissue can be measured by imaging techniques such as CT or MRI. Imaging this tissue provides the cardiologist with more information than standard diagnostic techniques, such as coronary calcium scoring, according to recent research by Emory cardiologists.

“This information may be used as a gatekeeper in that it could help a cardiologist decide whether a patient should go on to have a nuclear stress test,” says Emory radiologist Paolo Raggi.

Here’s why. Calcium, says Raggi, tends to build up in atherosclerotic plaques. And although the heart’s overall coronary calcium burden is a good predictor of heart disease, calcium in an individual plaque doesn’t necessarily spell imminent trouble, he says.

Instead, researchers are learning that the non-calcified plaques are the ones that indicate active buildup in the coronary artery. What’s more, studies show that fat around the heart secretes more inflammatory hormones than the fat just under the skin. Release of inflammatory factors from this tissue may be promoting an active atherosclerotic process and indicate the presence of the non-calicifed variety of plaque that causes trouble, says Raggi.

Emory researchers also have found that the volume of fatty heart tissue was a better indicator of ischemia (inadequate blood flow to the heart), than a coronary calcium score. A coronary calcium score indicates the presence, location, and extent of calcified plaque in coronary arteries.

In a separate study, researchers measured epicardial fat in patients already receiving a nuclear stress test. These patients had chest pain but were not known to have cardiovascular disease.

A nuclear stress test picks up signs of inducible ischemia. The researchers found the presence of ischemia correlated more closely with epicardial adipose tissue volume than with the coronary calcium score. —Robin Tricoles

     
 

Blogging for hearts

If you’re interested in anything to do with hearts, chances are that the new Emory heart blog, Advancing your Health, will cover it. And if not, you can suggest your topic to the cardiac surgeons and cardiologists who are blogging. So far, the blog has featured patient stories, ventricular-assist devices, and heart failure. To learn more, go to advancingyourhealth.org/heartblog/.

 
     

Table of Contents


Bookmark and Share

Cover


Subscribe


Subscribe for Updates
Sign up for Emory Health email