Report from ARRS: Cardiac CT angiography screening pays off if price is right

May 1, 2006

A powerful clinical case can be made for using cardiac CT angiography as a screening tool to help avoid cardiac catheterization. But does the technique make financial sense in nonemergent cases? A new cost-effectiveness study says yes -- if the price is right.

A powerful clinical case can be made for using cardiac CT angiography as a screening tool to help avoid cardiac catheterization. But does the technique make financial sense in nonemergent cases? A new cost-effectiveness study says yes - if the price is right.

"CTA may be useful in ruling out significant lesions, avoiding angiography," said Andrea Frangos, who presented a comparison Monday of CCTA with conventional catheter angiography in nonemergent patients at the American Roentgen Ray Society meeting in Vancouver.

Conventional angiography for outpatients costs almost $2800, based on 2005 Medicare reimbursement rates. Reports in the scientific literature show that from 10% to 30% of cardiac catheterizations in nonemergent cases are normal and, therefore, unnecessary, said Frangos, a research associate at Thomas Jefferson University in Philadelphia.

Using CCTA's known negative predictive value of 100% and specificity of 98%, researchers performed a decision tree analysis to determine the points at which CCTA becomes cost-effective.

CCTA becomes viable as a prescreening technique when priced up to $270, using the lower 10% estimate of normal results with conventional angiography. With the higher 30% normal rate, it becomes preferable as a screening test prior to conventional catheter angiography even when priced up to $810, Frangos said.

The cost-effectiveness of cardiac CTA is highly dependent on the rate of negative catheterizations with conventional techniques, Frangos said. Unfortunately, normal findings on angiography are not well documented, limitating cost analysis.

Frangos added that CCTA is also useful in revealing other findings, which could save on additional treatments and hospitalization costs related to catheterization. This particular study did not account for those savings. Instead, its scope was limited to a reimbursement rate comparison between CCTA and cardiac catheterization.

Thus CCTA may prove to be cost-effective at reimbursement rates higher than the figures in the study.