Heart procedures put patients at risk of radiation exposure

Heart imaging procedures can deliver substantial amounts of radiation to patients, according to a new study released Wednesday in the Journal of the American College of Cardiology.

In addition to raising cancer risk, which is well known, radiation can damage the heart muscle, the valves, or the coronary arteries, which is a fact, but not widely publicized.

The study cited by Reuters showed one in 10 adults under the age of 64 had a radiation-based heart procedure over a period of three years in five major healthcare markets. 

Myocardial perfusion imaging, an advanced type of heart stress test, accounted for 74 % of radiation exposure from heart scans, said Dr. Jersey Chen of Yale University School of Medicine.

And heart catheterization and stenting are the second biggest sources of radiation exposure. 

Chen and colleagues examined medical claims from nearly one million patients aged 18 to 64 insured by United Healthcare and found some patients got too much radiation.

Over a three-year period, more than 3,000 patients got more than 20 millisiverts a year, which is the upper safety limit for workers who have professional radiation exposure, and 75 patients hot more than 50 millisieverts a year.

The environment gives a dose of radiation between 3 to 20 millisieverts a year.

Dr. John Gofman, late nuclear physician and professor who worked for University of California-Los Angeles, said there is no safety threshold for radiation exposure.  Every tiny amount of radiation causes some small damage and the effect is cumulative.

Dr. Chen was quoted by Reuters as saying that "The average patient who gets a nuclear stress test is going to get 16 millisieverts each time. It's going to increase their risk on a statistical basis."

By David Liu