Prevalence of risk factors and asymptomatic carotid atherosclerosis in diabetic patients screened for silent myocardial ischemia by SPECT myocardial imaging

Abstract

Background: The aim of the study was to evaluate whether there is any association between myocardial ischemia, common risk factors and carotid artery ultrasound parameters in asymptomatic type 2 diabetic (DMT2) patients.

Material and methods: 60 asymptomatic DMT2 patients (pts) without known coronary artery disease (CAD) underwent one day rest Dypiridamole stress Tc-99m sestamibi single photon emission computed tomography myocardial perfusion scintigraphy (MPS). We used 17 segment models for perfusion analysis with the assessment of perfusion scores. Patients were studied for age, sex, hypertension, hyperlipidemia, hs-CRP, smoking, obesity and family history of cardiac disease. Color Ultrasound examination of carotid arteries was performed in all patients.

Results: 51 patients (pts) had hypertension, 48 pts had hyperlipidemia, 15 were smokers, 6 pts had BMI > 30 kg/m2 and 26 patients had positive family history for CAD. 18 (31%) patients had myocardial ischemia. Mild ischemia was found in 6 pts, moderate in 7 patients and severe ischemia in 5 patients. Carotid IMT was increased in 34 pts and 15 pts had carotid plaques. Mean c-IMT value in patients with normal MPS results was 0.7 ± 0.1; in moderate ischemia 0.9 ± 0.1 and in pts severe ischemia 1.0 ± 0.2. Multivariate analysis showed obesity, low HDL and increased diastolic blood pressure predictors of increased c-IMT. Increased pulse pressure (PP), age and non-HDL cholesterol were predictors for presence of carotid plaques. Multivariable analysis for prediction of stress induced ischemia showed OR 2.9 (95% CI 2.1-5.1) for male gender, OR 3.1 for systolic blood pressure (95% CI 1.9-3.8) and OR 2.8 for LDL cholesterol (95% CI 1.7-3.6).

Conclusions: Our study has shown high prevalence of traditional risk factors and silent myocardial ischemia in type 2 diabetic patients, with the importance of SPECT imaging in selected diabetes type 2 patients. The study highlights the importance of screening for carotid atherosclerosis, which may be useful to identify diabetic patients at higher risk for coronary artery disease..

Keywords: carotid artery disease; myocardial ischemia; myocardial perfusion scintigraphy; risk factors.