Study: Large increase in unnecessary cardiac stress testing with imaging

The overuse of cardiac stress testing with imaging has led to unnecessary healthcare spending, as well as increased patient exposure to radiation, according to a study in the Annals of Internal Medicine.

For the purposes of the study, Joseph Ladapo, an assistant professor in the departments of medicine and population health at NYU Langone Medical Center, and colleagues used data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1993 to 2010.

The researchers compared rates of cardiac stress testing in the two-year periods of 1993-95 and 2008-10, and found that the number of ambulatory visits in the U.S. in which a cardiac stress test was ordered or performed increased by 50 percent. Stress tests with imaging comprised an increasingly large portion of those tests, growing from 59 percent in 1993-95 to 87 percent in 2008-10.

According to the study, about 1 million of those tests were probably inappropriate, at a cost of about $500 million and an estimated 491 future cases of cancer from radiation exposure.

The researchers also determined that while the growth in cardiac stress testing can be attributed to population and provider characteristics, that’s not the case for imaging.
“Cardiac stress testing is an important clinical tool, but we are overusing imaging for reasons unrelated to clinical need. This is causing preventable harm and increasing healthcare costs,” Ladapo said in an announcement. “Reducing unnecessary testing also will concomitantly reduce the incidence of radiation related cancer. We estimate that about 500 people get cancer each year in the U.S. from radiation received during a cardiac stress test when, in fact, they most probably didn’t need any radiological imaging in the first place.

“While this number might seem relatively small, we must remember that ‘first, do no harm’ is one of the guiding principles in medicine.”

The researchers suggested that the implementation of clinical decision support could help reduce stress testing with imaging.