It's not enough to simply say that cardiac catheterization is overused, he said. "What we want to do is use it more efficiently," Patel said, "to determine the features that indicate catheterization is necessary."
The study "points out a problem, but is not suggesting a solution," he said. A national data bank on catheterization may provide information pointing toward a solution, as may some randomized trials that are now underway, Patel noted.
One of those trials, in which Patel is participating, is comparing the results of routine stress testing with computerized tomography angiography, which gives a three-dimensional view of the heart arteries, in 10,000 people.
The cardiac catheterization study results are not surprising, said Dr. Andrew Einstein, an assistant professor of clinical medicine at Columbia University Medical Center, whose specialty is cardiac imaging. An old rule of thumb is that one-third of cardiac catheterizations will show no artery blockage, he noted.
"This study does provide stronger data than we have ever had in the past," Einstein said. "The important takeaway message is that better risk stratification is needed to inform decisions about catheterization. If we have a good strategy, people will not be referred as often for these invasive procedures."
And cost is an inevitable issue in making those decisions, he added. "The cost of a diagnostic catheterization at our hospital is $2,600," Einstein said.
The why and how of cardiac catheterization are explained by the U.S. National Library of Medicine.
SOURCES: Manesh Patel, M.D., assistant professor, medicine, Duke University, Durham, N.C.; Andrew Einste
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