Level 2: Mid-level evidence
Patients with diabetes are known to be at increased risk for coronary artery disease (CAD) as well as silent ischemia. The Detection of Ischemia in Asymptomatic Diabetics (DIAD) trial evaluated using adenosine-stress radionuclide myocardial perfusion imaging to screen 1,123 patients with diabetes who had no cardiovascular symptoms (JAMA. 2009;301:1547-1555). Results showed no significant differences between screening and no-screening groups in cardiac mortality (1.4% vs. 1.2%), all-cause mortality (3.2% vs. 2.7%), or rate of MI (1.3% vs. 1.7%). Use of medications for primary prevention (aspirin, ACE inhibitors, and statins) and glycemic control increased significantly in both groups over the course of the study. The cumulative cardiac event rate of 2.9% over mean 4.8 years of follow-up was significantly lower than anticipated in the trial design, which may have caused the study to be underpowered.