Evaluation of Silent Myocardial Ischemia with Single-Photon Emission Computed Tomography/Computed Tomography in Asymptomatic Subjects with Diabetes and Pre-Diabetes

Abstract

Objective:The aim of this study was to disclose the prevalence of myocardial ischemia, as detected by adenosine stress myocardial perfusion imaging (MPI) with hybrid single-photon emission computed tomography/computed tomography (SPECT/CT), in asymptomatic diabetic and pre-diabetic patients and to find out whether ischemia predicted the occurrence of adverse cardiac/cerebrovascular events (ACCE) at follow-up.Methods:Forty-three diabetic and thirty-five pre-diabetic asymptomatic patients without any history of coronary artery disease, underwent MPI and were followed-up for a 12.8±2.2 (8-19) months for the occurrence of ACCE. Baseline variables that would predict the presence of ischemia and the value of ischemia on MPI for predicting the occurrence of ACCE at follow-up were evaluated by logistic regression analysis.Results:Ischemia was detected in ten (23.3%) of the diabetic and in four (11.4%) of the pre-diabetic patients. The presence of diabetes was the only independent predictor of myocardial ischemia [odds ratio (OR): 12.31, 95% confidence interval (CI): 1.83-82.66; p<0.01]. During 12.8±2.2 (8-19) months of follow-up, ACCE was observed in five out of 78 (6.4%) patients. Patients with ischemia were significantly more likely to have ACCE during follow-up as compared to those with normal MPI scans (event rates: 21.4% vs. 3.1%, OR: 8.455 95% CI: 1.264-56.562, p=0.038).Conclusion:Myocardial ischemia as detected by adenosine stress SPECT/CT in a population of asymptomatic patients with diabetes mellitus or pre-diabetes appeared to predict the occurrence of ACCE at follow-up.

Significance of Microalbuminuria in Predicting Silent Myocardial Ischemia in Patients with Type 2 Diabetes Using Myocardial Perfusion Imaging

“…SMI is the most common manifestation of CAD in diabetic patients and can be manifested as myocardial infarction or death in some patients. The reported prevalence of SMI in diabetic patients ranges between 6 to 57% (17,18), but it was estimated 65% in our recent study which could be related to the use of different methodologies through the studies. Diabetic neuropathy is the most common underlying cause of silent ischemia in about 22-42% of asymptomatic diabetic patients (19,20,21).…”

Non-Invasive Assessment of Myocardial Perfusion Abnormality in Type 2 Diabetic Patients Without Symptoms of Coronary Artery Disease by SPECT-MPI

“…For GSPECT-MPI, a one-day stress-rest protocol was followed, and pharmacological stress was done by injection of adenosine at a dose of 140 g/kg body weight per minute for 6 minutes. The radiopharmaceutical 99m Tc-sestamibi was injected both at stress (7-10 mCi) and rest (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). SPECT image acquisition was done approximately 30-90 minutes after radiopharmaceutical injection, both under stress and at rest.…”

“…Stress myocardial perfusion imaging (MPI) may be explored for advanced cardiovascular risk assessment in asymptomatic persons with diabetes, according to the American College of Cardiology (ACC) practice guidelines (class IIb). The European Society of Cardiology has proposed a similar degree of recommendation (class IIb) for screening selected high-risk diabetic individuals for the prevalence of silent MI (15).…”