Frequently performed after heart attacks,cardiac imaging procedures are increasing the radiation exposure of patients as well as their long-term cancer risk, a new research says.

According to what is believed to be the first study to directly link cumulative exposure to low dose ionizing radiation, to cancer risk, 12,020 cancers were detected in follow up research of 82,861-size population, two thirds of which affected the abdomen, pelvis and chest areas. The Canadian research team at McGill University Health Center (MUHC) and the Jewish General  Hospital, Montreal, examined data on 82,861 patients who had suffered a heart attack between April 1996 and March 2006, but without any cancer history.

Within a year of the attack, 77% of all the patients underwent at least one heart procedure with low-dose radiation. Patients' exposure to radiation was higher when treated by a cardiologist as opposed to a general practitioner.

Dr. Louise Pilote, an epidemiology researcher at the Research Institute of the McGill University Health Center (MUHC), director of the internal medicine division at MUHC, and her colleagues wrote "We found a relation between the cumulative exposure to low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction [heart attack], and the risk of incident cancer,"

They continued "Although most patients were exposed to low or moderate levels of radiation, a substantial group were exposed to high levels and in general tended to be younger male patients with fewer co-morbidities [co-existing health problems],"

The researchers concluded "These results call into question whether our current enthusiasm for imaging and therapeutic procedures after acute myocardial infarction should be tempered. We should at least consider putting into place a system of prospectively documenting the imaging tests and procedures that each patient undergoes and estimating his or her cumulative exposure to low-dose ionizing radiation."