Abstract 12642: Nonspecific ST and T Wave Abnormalities on Resting Electrocardiography Predict Cardiovascular Events and Inducible Ischemia in Asymptomatic Diabetics in the Detection of Ischemia in Asymptomatic Diabetes Study
Background: Nonspecific ST and T wave abnormalities (NSSTTA) on resting ECGs are associated with increased cardiovascular risk. Although NSSTTA are often neglected, they could potentially enhance cardiovascular risk stratification in patients with asymptomatic diabetes. We hypothesized that NSSTTA on resting ECGs can predict myocardial perfusion defects and cardiac events in asymptomatic diabetics.
Methods: A post-hoc analysis of 1,123 patients with type 2 diabetes, free of symptoms of cardiac disease, in the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study. Patients were randomly assigned to screening (or no screening) with adenosine-stress myocardial perfusion imaging (MPI) and routine care by their primary provider. All patients received a resting 12-lead ECG; 4 patients were excluded in this analysis due to incomplete outcomes data. The Minnesota Code Manual of ECG Findings was utilized to determine the presence of NSSTTA. The primary cardiac events were myocardial infarction and cardiac death. The mean follow up was 4.8 years.
Results: The prevalence of NSSTTA on baseline ECGs was 18.2% (204/1,119). Patients with NSSTTA versus those without NSSTTA had a higher incidence of abnormal stress MPI (31% vs. 20%, p = 0.03), more primary cardiac events (6.4% vs. 2.1%, p < 0.01), and greater all-cause mortality (5.9% vs. 2.3%, p < 0.01). Patients with NSSTTA who were initially screened versus those not screened had a lower rate of primary cardiac event rate during follow up (4.3% vs. 8.1%, p < 0.01).
Conclusions: In the DIAD study, NSSTTA were associated with 1) more abnormal stress MPI, 2) an increased incidence of myocardial infarction and cardiac death, and 3) greater all-cause mortality, compared with those without NSSTTA. Patients with NSSTTA who were screened with MPI had improved cardiac outcomes. Thus, asymptomatic diabetics with NSSTTA constitute a higher risk sub-group. Prospective studies are needed to confirm that screening diabetic patients with NSSTTA improves cardiovascular outcomes. (ClinicalTrials.gov number, NCT00769275)
- © 2010 by American Heart Association, Inc.