BOSTON — Screening asymptomatic diabetes patients for myocardial ischemia using advanced imaging does not improve their 5-year prognosis for coronary events, compared with standard care, results of a multicenter study have shown.
Of the 561 type 2 diabetes patients without symptomatic or previously diagnosed coronary artery disease who underwent screening with stress adenosine myocardial perfusion imaging (MPI) as part of the study, “only 22% had inducible ischemia, which was far less than we expected,” Dr. Frans J. Wackers of Yale University, said at the annual meeting of the American Society of Nuclear Cardiology.
During a mean follow-up of 4.8 years, the cumulative rate of cardiac events for both groups was about 3% among patients in the screening group and among the 562 patients in the standard care control group.
The study randomized 1,123 patients, aged 55–75 years, with a mean diabetes duration of 8.7 years to MPI single-photon emission computed tomography screening or standard care without screening.
Patients with normal MPI or small MPI defects had 5-year cumulative cardiac event rates of 2.1% and 2.0%, respectively. Among patients with moderate to large MPI defects, as well as those with nonperfusion abnormalities such as ischemic changes on electrocardiogram, rates were significantly higher, at 12.3% and 6.8%, respectively.
Predictors of cardiac events by Cox regression included male sex, peripheral vascular disease, creatinine level, and abnormal heart rate response to standing.
Clinical events and inducible ischemia both identify higher-risk patients with type 2 diabetes, “but overall rates of cardiac events are equivalent whether or not patients underwent initial screening,” said Dr. Wackers, who reported no financial conflicts of interest.