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, study results have shown.
In addition, 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, there was no difference in the rates of cardiac events between patients in the screening group and the 562 patients in the standard care control group, he said, noting that the cumulative rate of cardiac events for both groups was approximately 3%.
The multicenter 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 (SPECT) 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. However, the cumulative rates among patients with moderate to large MPI defects, as well as those with nonperfusion abnormalities such as ischemic changes on electrocardiogram, 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.
The findings indicate that clinical events and significant 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.