Cardiac Testing May Put Younger Adults at Radiation Risk

Some screening tests may expose young adults to considerable radiation.

ByABC News
July 8, 2010, 3:30 PM

July 10, 2010— -- Nearly one in 10 adults under age 65 in the United States gets radiation exposure from cardiac imaging over a given three-year period, researchers have found.

The researchers analyzed administrative claims from a major U.S. insurer for more than 90,000 nonelderly adults who underwent at least one cardiac imaging procedure. They found that 89 per 1,000 received an effective dose of ionizing radiation from the procedures greater than what these patients would normally receive through exposure to background radiation from natural sources.

Another 3.3 per 1,000 got cumulative annual doses above the upper limit for occupational exposure averaged over five years, Dr. Jersey Chen of Yale University in New Haven, Conn. and colleagues reported online in the Journal of the American College of Cardiology.

Extrapolating these results to the U.S. population in the same age range suggested that 636,000 people would be at risk from high cumulative effective doses of ionizing radiation from cardiac imaging, which the researchers called "considerable."

The public health and clinical implications aren't easy to determine since the cancer risk that comes with ionizing radiation is countered by the benefit of catching and treating potentially life-threatening heart problems, they noted.

But since cardiac imaging appeared to account for about 30 percent of the total annual exposure to radiation from medical testing overall, cardiologists bear particular responsibility for minimizing risk by selection of tests and optimal technical practices, Chen's group said.

An accompanying JAAC editorial agreed that these results should give cardiologists pause.

But Dr. Matthew J. Budoff and Dr. Mohit Gupta, both of Harbor UCLA Medical Center in Torrance, Calif., cautioned in the editorial "that the entire premise that radiation doses from medical testing causes cancers remains hypothetical."

Although ionizing radiation at high levels like atomic bomb exposure causes cancer and death, "the relationship between low-dose medical imaging and harm has never been established," they wrote in the editorial.