Cost of peripheral CTA compares favorably with MRA

Multidetector-row CT angiography has the potential to be cost-effective for evaluating patients with intermittent claudication, according to researchers from the Netherlands and the U.S.

Investigators from University Medical Center Rotterdam and Harvard Medical School used a decision model to compare the societal cost-effectiveness of CTA with that of gadolinium-enhanced MRA. Main outcome measures were quality-adjusted life years (QALYs) and lifetime costs. The base evaluation used 60-year-old men with severe intermittent claudication and an assumed incremental cost-effectiveness threshold of $100,000 per QALY.

The study revealed that a specific set of targets will allow a CTA workup to compete cost-effectively with an MRA workup for patients suffering from intermittent claudication caused by significant stenosis.

In the minimally invasive treatment scenario (angioplasty), cost-effectiveness was equivalent for CTA and MRA if CTA cost $420, its sensitivity to detect significant stenosis was 90%, and no more than 20% of patients required additional workup owing to equivocal CTA results. In 1997, a CTA exam cost $237, the authors said.

If CTA cost $300 or less and had a sensitivity of at least 85%, it would still be cost-effective compared with MRA, even if up to 35% of patients needed additional workup, said Karen Visser, Ph.D, a postdoctoral fellow at Rotterdam when the trial was conducted.

CTA is simple to perform, fast, and quickly becoming widely available, according to Visser. Preliminary results of CTA for the workup of patients with peripheral arterial disease show a high diagnostic accuracy and sensitivity close to the study's estimated target value of 85%.
In the more invasive treatment scenario (bypass surgery), cost-effectiveness of CTA would be equivalent to MRA if the cost was $673 and sensitivity 95%, and no more than 20% of the patients required further workup with digital subtraction angiography.

In order for CTA to remain cost-effective in this scenario at a cost of $300, sensitivity would have to be higher than 94% and no more than 20% of patients could be referred for further DSA workup.

"Calculations of this kind can help focus not only the development of new modalities for the diagnostic workup of peripheral arterial disease, but also the development of new technologies in healthcare in general," the authors said.

The researchers are currently running a randomized clinical trial comparing CTA and MRA in a practical setting, Visser said.

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