Cardiac Catheterizations: Too Many Performed?
Study Shows Many Patients Who Have the Procedure Don't Have Blocked Arteries
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How Cardiac Catheterizations Work continued...
Most of these patients had undergone noninvasive cardiac testing, such as an
exercise stress test or
electrocardiogram, before having a coronary angiography. But only 38% ended up
having significant coronary artery blockages.
"This suggests that our ability to identify disease prior to sending
patients to the cardiac cath lab is not as good as it should be," Duke
assistant professor of medicine and study co-researcher Manesh R. Patel, MD,
Douglas points out that the widely used noninvasive tests are not very
accurate in moderate- to low-risk patients.
"These patients are more likely to have a false positive finding than a true
positive finding, and end up having the invasive testing when they don't need
it," she says.
Both researchers say more research is needed to determine how to best manage
patients with stable chest pain without a diagnosis of heart disease.
Douglas is leading one of the first major trials to do this: a
10,000-patient, $5.5 million study funded by the National Heart Lung and Blood
Institute that will compare traditional exercise stress testing to the
noninvasive imaging procedure known as CT angiogram.
American Heart Association president Clyde Yancy, MD, agrees that such
studies are needed, but he says it is not clear from the current research that
too many cardiac catheterizations are being done.
"A test that fails to find something may be just as valuable as a positive
test," he says. "A negative test can reassure both the patient and the doctor.
It can also lead to less unnecessary treatment, which can save health care
The biggest predictors of clinically significant artery blockages in the
study were recognized risk factors for heart disease, such older age, being
male, tobacco use, and having diabetes, high cholesterol or high blood
Yancy says understanding these risk factors and addressing those that are
modifiable is the most important thing patients can do to lower their heart
attack and stroke risk.
"If an older male who smokes and is overweight and has diabetes walks into
my office, I already know there is a pretty high likelihood of [heart or
vascular] disease," he says.