Routine screening for coronary artery disease in type 2 diabetes patients with no symptoms of angina or a history of coronary disease is unnecessary and may lead initially to more invasive and costly heart procedures, according to researchers at Yale School of Medicine. They report their findings in the April 15 Journal of the American Medical Association.
"Patients with type 2 diabetes with no symptoms who are feeling well can generally be managed effectively with preventive therapies such as lipid-lowering drugs, blood pressure medication, aspirin and diabetes treatment," said Lawrence Young, M.D., professor of medicine at Yale School of Medicine.
Coronary artery disease is a major cause of death and disability in patients with type 2 diabetes, who often undergo routine screening with stress testing. In this study, Young, Frans J. Wackers, M.D., Silvio Inzucchi, M.D., Deborah Chyun, and other colleagues sought to determine whether routinely screening diabetic patients without a history of heart problems helped identify those at higher cardiac risk.
The team spearheaded the Detection of Ischemia in Asymptomatic Diabetics study in which 1,123 participants were randomly assigned to either a screening stress test that looks at the blood flow to the heart, or to a group that received no screening. Participants enrolled at 14 centers in the United States and Canada and were evaluated over the next five years.
The team found that routine screening of type 2 diabetics identifies a small group of patients at higher risk, but does not significantly affect overall outcome. With each test costing about $1,000, and with 200 million patients with diabetes worldwide, Young says, "Routine screening would have tremendous economic implications and our findings did not indicate that routine stress testing had additional benefit in this population." The study also found that routine screening leads initially to more invasive procedures such as cardiac catheterization, stents or bypass.
"On the other hand,ö he cautioned, ôstress testing has an important role in evaluating patients with type 2 diabetes who have symptoms suggesting heart disease, since these individuals are at very high risk."
"This is a bit of good news in the field of diabetes where patients and their physicians have real concern for heart disease. In patients getting modern medical therapy in our study, serious heart problems were infrequent," said Young.
Other authors on the study included Janice Davey, Eugene Barrett, M.D., Raymond Taillefer, M.D., Gary Heller, M.D., Ami Iskandrian, M.D., Steven Wittlin, M.D., Neil Filipchik, M.D., Robert Ratner, M.D.
Citation: JAMA 301:1547-1555 (April 15, 2009)