Identifying high-risk asymptomatic diabetic patients who are candidates for screening stress single-photon emission computed tomography imaging.
OBJECTIVE
The purpose of this study was to identify which asymptomatic diabetic patients are candidates for screening single-photon emission computed tomography (SPECT) imaging and to examine angiographic findings and mortality in patients according to SPECT imaging categories.


BACKGROUND
Previously we reported a high percentage of abnormal and high-risk SPECT imaging scans in asymptomatic diabetic patients.


METHODS
We examined the associations between several clinical and laboratory variables and a high-risk stress SPECT imaging scan in 1,427 asymptomatic diabetic patients without known coronary artery disease (CAD). Results of coronary angiography and long-term outcome were also analyzed.


RESULTS
An abnormal stress SPECT imaging scan was present in 826 patients (58%) and a high-risk scan in 261 patients (18%). Multivariate analysis demonstrated that seven variables were independently associated with a high-risk scan (model chi-square=107, p <0.0001). The two most important variables were electrocardiogram (ECG) Q waves (adjusted chi-square=38.3, p <0.001) and peripheral arterial disease (PAD) (adjusted chi-square=13.9, p <0.001). Coronary angiography was performed in 127 (49%) high-risk SPECT imaging patients, 61% of whom had angiographic high-risk CAD. Annual mortality rates for patient subsets categorized by SPECT imaging scans were high-risk 5.9%, intermediate-risk 5.0%, and low-risk 3.6% (p <0.001 for differences between groups).


CONCLUSIONS
High-risk findings on stress SPECT imaging were present in 18% of asymptomatic diabetic patients without known CAD. Patients with high-risk scans had a high prevalence of severe CAD and a high annual mortality rate. ECG Q waves and/or evidence of PAD identified the most suitable candidates for screening.
Rajagopalan
Navin
N
Department of Internal Medicine and Cardiovascular Diseases, Mayo, Rochester, MN 55905, USA.
Miller
Todd D
TD
Hodge
David O
DO
Frye
Robert L
RL
Gibbons
Raymond J
RJ
D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000401:mortality; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000401:mortality; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D018579:Patient Selection; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment; D015899:Tomography, Emission-Computed, Single-Photon