WASHINGTON (Reuters) - Doctors should be judicious in their use of X-ray heart imaging techniques and avoid their routine use to screen for cardiac problems, a leading U.S. medical group said on Monday.
The American Heart Association urged doctors to weigh risks and benefits carefully in ordering diagnostic tests such as computed tomography, or CT, angiograms and nuclear stress tests in order to minimize the doses of ionizing radiation.
Such low-dose radiation has the potential to cause cancer.
A coronary CT angiogram is a heart-imaging test used to see whether fatty or calcium deposits have built up in the arteries that supply blood to the heart muscle. Nuclear stress tests are used to look for lack of blood flow in the heart muscle that could indicate a blockage in a heart artery.
"A patient who is at low risk of having heart disease and who has no symptoms suggestive of heart disease, we really don't think they should have these scans," Dr. Thomas Gerber of the Mayo Clinic in Jacksonville, Florida, said in a telephone interview.
Gerber headed the American Heart Association panel that wrote the scientific advisory, which concludes that "cardiac imaging studies that expose patients to ionizing radiation should be ordered only after thoughtful consideration of the potential benefit to the patient."
Gerber called the tests valuable tools for doctors, and said he did not want to "convey the alarmist message that these scans are inherently dangerous and shouldn't be done." Gerber added: "Our mantra is: the right tests in the right patient."
But medical imaging techniques represent the biggest source of controllable radiation exposure of Americans, and doctors need to be mindful of the potential harm from even relatively small doses of radiation, Gerber said.
"We're really trying to urge doctors that when they see a patient and have a clinical question, to think whether or not that clinical question can be answered without the use of ionizing radiation," Gerber said.
The advisory, published in the journal Circulation, also said that once a doctor has established that a cardiac imaging test that uses ionizing radiation is needed, "every effort should be made" to reduce the radiation dose.
There is no federal regulation of radiation dose except for mammograms used to screen for breast cancer, leaving appropriate use of scanning equipment and radiation dose up to doctors and medical facilities, according to the advisory.
Editing by Maggie Fox