Cardiac Catheterizations: Too Many Performed?
Study Shows Many Patients Who Have the Procedure Don't Have Blocked Arteries
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, tells WebMD.
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 dollars."
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 pressure.
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.