Prevalence and predictors of coronary artery disease in egyptian diabetic patients using myocardial perfusion SPECT

الملخص EN

Background : diabetes mellitus is a growing medical problem among Egyptian population.

Although diabetes is an established major risk factor for coronary artery disease (CAD) and consequently carries a poor prognosis ; stress test imaging is not recommended for the routine evaluation of diabetic patients with suspected CAD.

Understanding the prevalence of CAD and predictors of CAD in diabetics will assist clinical decision making in the evaluation for ischemia in this population.

The aim of this study was to assess the prevalence and the clinical predictors of myocardial ischemia by SPECT imaging in patients (PTS) with diabetes and suspected CAD Methods : 679 consecutive pts referred for a diagnostic MPS underwent exercise stress / rest Thallium 201 SPECT.

Images were analyzed using 20 segment 5-point scale (0 = normal to 4 = no uptake) and summed stress SSS, summed rest scores (SRS) and summed difference scores (SDS) were then calculated.

MPS was considered positive when SSS > 3.

Logistic regression model was used to determine whether any of the clinical variables considered (age, gender, hypertension, smoking, hypercholesterolemia, family history of CAD, typical angina as a presenting symptoms and ST segment changes on stress ECG) was associated with ischemia at SPECT.

Results : Of the 679 pts, mean age was 53.4 ± 7.6, with a mean number of risk factors 1.2 ± 1.0.

76.7 % were males, 25.5 % had diabetes, 43.4 % had hypertension, 24.4 % were smoker and 27.8 % had hyperlipidemia.

All pts were symptomatic, 78.8 % presented with chest pain, 331 (48.7 %) had a positive ET and 74.1 % had a positive MPS with a mean SSS of 6.9 ± 5.1 SDS mean 4.7 ± 3.7 & mean SRS of 2.2 ± 3.1.

Comparison between diabetics and non diabetics are summarized in table 1.

Of the clinical variables considered only the male gender and positive stress ECG changes were predictive of ischemia in both diabetics and non diabetics.

Conclusions : As expected, the prevalence of ischemia at SPECT is higher in diabetic patients.

The finding that traditional cardiac risk factors fail to predict myocardial ischemia at SPECT, supports the need for careful noninvasive functional evaluation of diabetic patients with no history of CAD.