EBCT Diagnoses Blocked Arteries Without Stress Test

An analysis of nine studies has shown that electron beam computed tomography (EBCT) can diagnose blocked arteries just as reliably as stress tests in patients with coronary artery disease (CAD). The analysis, conducted by researchers from the University of Michigan (U-M, Ann Arbor, MI, USA), was published in the March 26 issue of the Archives of Internal Medicine.

The U-M researchers looked at studies involving 1,662 patients with chest pain or other symptoms of CAD and evaluated EBCT's use in finding plaques that blocked more than half of any given artery, enough to alter blood flow dangerously. They compared how often the test found real plaques and how often it gave a false positive, depending on how the EBCT machines were set. Overall, they found that at the optimum setting for reliability, EBCT's sensitivity was 75% and its specificity was 75%. These levels of reliability are similar to what can be achieved by treadmill stress tests using monitors and/or radioactive tracers.

The test is faster, more consistent, and easier to perform than stress tests. However, the equipment used to conduct the scan is expensive. The researchers found that similar levels of accuracy could be attained by using existing CT scanners equipped with special software that analyzes calcium density in arteries. This approach is being explored by the U-M Health System for its Cardiovascular Center.

"Frankly, we were surprised that the test showed this level of reliability in diagnosing coronary artery disease in these patients,” said Brahmajee Nallamothu, M.D., a U-M cardiology fellow.




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