Detection of silent myocardial ischemia in asymptomatic diabetic subjects: the DIAD study.
OBJECTIVE
To assess the prevalence and clinical predictors of silent myocardial ischemia in asymptomatic patients with type 2 diabetes and to test the effectiveness of current American Diabetes Association screening guidelines.


METHODS
In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 1,123 patients with type 2 diabetes, aged 50-75 years, with no known or suspected coronary artery disease, were randomly assigned to either stress testing and 5-year clinical follow-up or to follow-up only. The prevalence of ischemia in 522 patients randomized to stress testing was assessed by adenosine technetium-99m sestamibi single-photon emission-computed tomography myocardial perfusion imaging.


RESULTS
A total of 113 patients (22%) had silent ischemia, including 83 with regional myocardial perfusion abnormalities and 30 with normal perfusion but other abnormalities (i.e., adenosine-induced ST-segment depression, ventricular dilation, or rest ventricular dysfunction). Moderate or large perfusion defects were present in 33 patients. The strongest predictors for abnormal tests were abnormal Valsalva (odds ratio [OR] 5.6), male sex (2.5), and diabetes duration (5.2). Other traditional cardiac risk factors or inflammatory and prothrombotic markers were not predictive. Ischemic adenosine-induced ST-segment depression with normal perfusion (n = 21) was associated with women (OR 3.4). Selecting only patients who met American Diabetes Association guidelines would have failed to identify 41% of patients with silent ischemia.


CONCLUSIONS
Silent myocardial ischemia occurs in greater than one in five asymptomatic patients with type 2 diabetes. Traditional and emerging cardiac risk factors were not associated with abnormal stress tests, although cardiac autonomic dysfunction was a strong predictor of ischemia.
Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA. frans.wackers@yale.edu
Frans J Th
FJ
Wackers
Lawrence H
LH
Young
Silvio E
SE
Inzucchi
Deborah A
DA
Chyun
Janice A
JA
Davey
Eugene J
EJ
Barrett
Raymond
R
Taillefer
Steven D
SD
Wittlin
Gary V
GV
Heller
Neil
N
Filipchuk
Samuel
S
Engel
Robert E
RE
Ratner
Ami E
AE
Iskandrian
D002170:Canada; D003327:Coronary Disease / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003925:Diabetic Angiopathies / Q000453:epidemiology; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology*; D010045:Outpatients; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014481:United States
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi