Thus, although prospective trial data are still lacking, if “in the judgment of the clinician, an asymptomatic patient is a candidate for CAD testing, it is reasonable to apply cardiac CT for detection of coronary artery calcification, using either electron beam or multislice technology, as the first step,” the panel recommended.
Several studies have suggested that a coronary calcium score of 400 or greater is associated with a high likelihood of inducible ischemia, including one study that looked specifically at asymptomatic patients with diabetes (Eur. Heart J. 2006;27:713–21).
Thus, if coronary calcium testing is performed, it “appears reasonable” to proceed with further testing in diabetes patients with coronary calcium scores greater than 400. Such further testing could be done with single photon emission tomography to assess myocardial perfusion, or with stress echocardiography to assess ischemic wall motion abnormalities, the panel said.
▸ What further research is needed to evaluate the effectiveness of these recommendations? As a first step, the development and testing of improved risk prediction models against data available from national registries would be particularly helpful in capturing general population risk data, Dr. Bax and his associates said.
In the BARI 2D (Bypass Angioplasty Revascularization Investigation in Type 2 Diabetes) study, patients with type 2 diabetes and documented CAD have been randomized to immediate revascularization combined with aggressive medical management, or a program of aggressive medical management with delayed or no revascularization. This study will provide important insight to assist in the development of strategies for the treatment of asymptomatic patients.