NEW YORK — Coronary calcium scanning followed by myocardial perfusion imaging looks like it may be an effective approach to screening for coronary disease, John J. Mahmarian, M.D., said at the annual meeting of the American Society of Nuclear Cardiology.
“Further investigation needs to focus on the complementary role of CT scanning [for coronary calcium] and SPECT [single-photon emission computed tomography] for more precisely defining patient risk and recommending who should receive aggressive, antiatherosclerotic treatments,” said Dr. Mahmarian, medical director of the nuclear cardiology laboratory at the Methodist Hospital, Houston.
“About 25% of people with three, four, or five risk factors for coronary disease have very little coronary calcification, and about 25% of patients with very high calcium scores have zero or one risk factor,” Dr. Mahmarian noted. People with high coronary calcium scores have a markedly increased risk of having myocardial perfusion defects and significant coronary disease. Screening for coronary calcium makes sense for people with an intermediate or high risk for coronary disease based on their risk factor profile.
Dr. Mahmarian proposed that people who have a calcium score of less than 100 do not need additional, immediate testing but should be managed for risk factor reduction. People with a calcium score of 100-399 should be placed on an aggressive, risk-factor reduction regimen and are candidates for SPECT testing. These people should have follow-up screening for coronary calcium every 1-2 years. Dr. Mahmarian said that about 15% of people screened could be in this category.
Those with a calcium score of more than 400—about 10% of the screening population—should receive aggressive risk-factor management plus noninvasive testing by SPECT.