Although prior studies of screening for coronary artery disease (CAD) in high-risk patients have failed to demonstrate benefit, screening with cardiac coronary computed tomography (CCTA) may hold promise by providing more detail on the extent of coronary atherosclerosis.  This trial randomized 900 patients with a 3 to 5 years history of type 1 or 2 diabetes mellitus, but without known CAD, to screening with cardiac CCTA versus usual care.  Patients randomized to CCTA received management recommendations based on scan results that included aggressive risk factor modification for findings of CAD.  The primary outcome was a composite of all-cause mortality, nonfatal myocardial infarction, or unstable angina requiring hospitalization.  There were no significant differences between the CCTA screening and usual care groups on any of the outcomes in both intention-to-treat and as-treated analysis. Notably there were lower than expected rates of events (~2%) in both the treatment and control groups.

Conclusion:  Screening with CCTA did not result in a decrease in mortality or non-fatal MI among diabetic patients without CAD symptoms.  Although a larger trial may be needed because the low event rate reduced the power of this study, routine screening with CCTA is not recommended currently.

Summarized by Lauren E. Thompson and Steven M. Bradley

• Muhlestein JB, Lappé DL, Lima JA, Rosen BD, May HT, Knight S, Bluemke DA, Towner SR, Le V, Bair TL, Vavere AL, Anderson JL. Effect of screening for coronary artery disease using CT angiography on mortality and cardiac events in high-risk patients with diabetes: the FACTOR-64 randomized clinical trial. JAMA. 2014;312(21):2234-2243. doi:10.1001/jama.2014.15825.