Systematic screening may not be necessary for diabetic patients
BOSTON—Asymptomatic type 2 diabetes mellitus patients without symptomatic or previously diagnosed coronary artery disease have an overall highly favorable five-year prognosis with contemporary therapy, according to DIAD data presented during the late breaking clinical trial sessions on Sept. 13 at the American Society of Nuclear Cardiology (ASNC) meeting.

Data from the DIAD (Detection of Ischemia in Asymptomatic Diabetics) study assessed the prevalence of silent myocardial ischemia to discern whether coronary artery disease (CAD) screening should be offered to all people with type 2 diabetes.

"The DIAD study is the first large prospective study addressing the issue of whether a strategy of systematic screening for silent coronary artery disease alters cardiac outcome," said Frans Wackers, MD, from Yale University in New Haven, Conn., who presented the data.

Overall, 1,123 diabetic patients without symptomatic or previously diagnosed CAD were randomized to either screening with myocardial perfusion imaging (MPI) or standard care without screening. The cumulative rate of cardiac events was 3.3 percent. After an average five-year follow-up, researchers found a low overall cardiac event rate and no difference between the two groups.

Wackers and colleagues found that those with moderate or large MPI defects and those with non-perfusion abnormalities (i.e., ischemic ECG changes) had higher cardiac event rates: 12.3 percent and 6.8 percent, respectively.

Thus, the investigators said that “unexpectedly, diabetic patients without known CAD have an overall highly favorable five-year prognosis with contemporary therapy, such as aspirin, statins and ACE-inhibitors.”

“Systematic screening cannot be recommended in asymptomatic patients with diabetes,” Wackers said. “However, targeted screening, involving close clinical follow-up and clinically driven diagnostic testing, is appropriate. Using the latter approach, about 30 percent of initially asymptomatic patients had stress myocardial perfusion imaging in the standard-care arm of the DIAD study.”

Based on their results, the researchers concluded that screening does not provide a significant benefit to this patient population.