Heart Imaging Tool Under the Microscope
Usefulness of CTA Screening Unknown in People With No Symptoms
Radiation Risk a Concern
One big problem with the test is that it is not clear what the findings mean in patients with few risk factors for heart disease, Bolger tells WebMD.
"If you don't see coronary disease, is that person off the hook, and if you do see it does that mean that the person will have a coronary event in a year, or two, or five?" she says. "We can't answer these questions yet."
This, combined with a cost of anywhere from $500 to $1,500 per scan, and the radiation risk identified in earlier studies, makes it too soon to recommend CTA for the routine screening of asymptomatic people, she says.
The American Heart Association came to the same conclusion in a recently published statement on the use of new noninvasive techniques to measure arterial plaque, finding that CTA should not be used to screen for coronary artery disease in people with no evidence of disease.
But Bolger says it is only a matter of time before researchers gain a better understanding of the role of CTA and other new-generation tests designed to identify people at risk for heart attacks and strokes.
"With every year that goes by our understanding about these tests and how to use them gets better," she says.
American Heart Association past president Robert Bonow, MD, agrees.
Bonow calls CTA "a very exciting technology," but he tells WebMD that its safety and effectiveness for identifying coronary artery disease in asymptomatic populations remains to be determined.
A professor of medicine at Northwestern University, Bonow is also the chief of cardiology at Northwestern Memorial Hospital.
"Other (new-generation) tests that involve much less radiation are showing a lot of promise, so we will just have to see," he says.