Heart Scan Side Effects Could Raise Cancer Risk: Study

Canadian researchers indicate that they have found a direct correlation between heart imaging scans and an increased risk of cancer, with the risk growing in proportion to the amount of radiation a patient has received from the scans.

Every 10 milli Sieverts (mSv) a year received by a patient from heart imaging scans raises the risk of cancer by about 3%, according to researchers from Montreal, Quebec. The findings of their study were published online last week by the Canadian Medical Association Journal (CMAJ).

Resarchers looked at an administrative database of 82,861 patients who suffered a heart attack between April 1996 and March 2006. They found that 77% of those patients received either a cardiac imaging scan or a therapeutic procedure that involved subjecting the heart to low-dose ionizing radiation during the first year after their heart attack. In most cases, the radiation exposure was about 5.3 mSv per patient-year.

A total of 12,020 cancer incidents were discovered among the patients during the follow-up period. Researchers determined that there was dose-dependant relationship between the amount of radiation exposure from the heart imaging scans and the likelihood that the patient would develop cancer that equated to about 3% increased risk for every 10 mSv of low-dose ionizing radiation.

The researchers said that the findings raise questions as to whether health care professionals should back off on the heavy use of low-dose ionizing radiation scans. At a minimum, the researchers concluded that a system should be put in place that tracks the cumulative amount of radiation exposure received by a patient, so that their health care professionals can weigh that information when determining whether a heart imaging scan is the best course of action.