Yield of stress single-photon emission computed tomography in asymptomatic patients with diabetes

Background Patients with diabetes without clinically apparent coronary artery disease are at increased risk of cardiac death. The value of screening stress testing in these patients remains controversial. The goal of this study was to examine the yield of stress single-photon emission computed tomography (SPECT) in asymptomatic diabetic patients. Methods The results of stress SPECT in patients without prior myocardial infarction or coronary revascularization were compared in asymptomatic diabetics (n=1738) versus symptomatic diabetic patients (n=2998), asymptomatic nondiabetic patients (n=6215), and symptomatic nondiabetic patients (n==16,214). Results Abnormal scans were present in 58.6% of asymptomatic diabetic patients, approximately equal to the percentage in symptomatic diabetic (59.5%) (P=not significant) and higher than in asymptomatic nondiabetic (46.2%) (P<.001) and symptomatic nondiabetic (44.4%) (P<.001) patients. The breakdown of high-risk scans followed a similar pattern in the 4 patient subsets: asymptomatic diabetic, 19.7% versus symptomatic diabetic, 22.2% (P=.051); asymptomatic nondiabetic, 11.1% (P<.001); and symptomatic nondiabetic, 12.5% (P<.001). Patients with diabetes had more electrocardiographic and scan evidence for silent myocardial infarction versus those without diabetes. Conclusions Asymptomatic diabetic patients have a high prevalence of both abnormal and high-risk SPECT scans. The finding that approximately 1 in 5 of these individuals has a high-risk scan suggests a potentially more widespread application of screening stress SPECT in asymptomatic diabetic patients to identify those with severe coronary artery disease.