A study result showed that screening for asymptomatic coronary artery disease in patients with type 2 diabetes fails to significantly reduce future cardiac events. The researchers also concluded that routine screening for inducible ischemia in asymptomatic patients with diabetes mellitus should not be advocated. In this prospective study, the Detection of Ischemia in Asymptomatic Diabetics (DIAD) trial investigators randomized 1123 diabetic patients with no coronary artery disease symptoms to screening with adenosine-stress radionuclide myocardial perfusion imaging (MPI) or to no screening. Investigators reported in 2004 that ischemic abnormalities were detected in 25% of patients, but the silent myocardial ischemia was not terribly alarming, said Wackers. Severe abnormalities on the stress test occurred in approximately 6% of patients. Patients were then followed for an average of 4.8 years. Overall, the cumulative cardiac event rate was just 2.9% during follow-up, or an average of 0.6% per year. There were 15 events in the screening group and 17 events among those who weren't screened, a statistically nonsignificant difference. Similarly, there was no difference in any of the secondary end points, which included angina, heart failure, stroke, and revascularizations. Wackers noted that the overall rate of coronary revascularization was low in both groups, at 5.5% in the screened group and 7.8% in the unscreened group, so this did not explain the low rates of cardiac events in the study. Cardiac event rates did differ significantly according to the results of the stress MPI test. In the screened cohort, the 459 subjects with normal results and small MPI defects had significantly lower cardiac event rates than the 33 individuals with moderate or large defects. However, the event rate among these subjects is still low at 2.4% per year, and the moderate or large MPI defects on screening had a positive predictive value of just 12%.