Abstract
Introduction: Considering the significant prevalence of silent
myocardial ischemia and its related morbidity and mortality in
asymptomatic type two diabetic patients, it is not well known whether
early screening with MPI is cost-effective. However, predicting factors
are not elucidated.
Materials and Methods: This was a cross-sectional study
including 63 asymptomatic patients with type 2 diabetes mellitus (T2DM),
with normal ECG and ejection fraction. Patients with any history of
documented valvular, congestive or ischemic heart disease, renal or
hepatic failure were excluded. At first all patients were interviewed
and checked for risk factors and then patients underwent a two-day
rest/stress 99mTc-MIBI gated MPI SPECT. Data was assessed by QPS/QGS and
4DM software and evaluated by a nuclear medicine specialist with summed
stress score (SSS) of more than 4 defined as CAD.
Results: There were 42 females (67%) and 21 males (33%), with
a mean age of 61.33 ± 6.98 years and 7.97 ± 4.86 years history of T2DM.
CAD was detected in 26 (41.3%) patients and was significantly
associated with male gender, smoking, requiring insulin therapy and EF
(P-value = 0.019, 0.046, 0.05, 0.033, respectively). A significant
association was found between the duration of diabetes, especially when
>15y, and the probability of having CAD.. Multivariable
logistic regression revealed that smoking; male gender and diabetes
duration were the strongest independent predictors of abnormal MPI
results.
Conclusion: We found a high (46%) prevalence of abnormal
stress MPI SPECT in patients with type 2 diabetes mellitus, despite
being asymptomatic. Asymptomatic patients with a history of smoking,
long duration of diabetes, being under insulin treatment and male gender
might benefit from MPI for early detection of silent ischemia.
Keyword: 99mTc-MIBI; Gated Myocardial Perfusion Imaging; Type 2
Diabetes Mellitus; Silent Ischemia; Asymptomatic CAD; Early Screening
Highlights:
- The prevalence of type2 DM is increasing
- Many patients with type 2 diabetes develop CAD
- The optimal CAD screening tool for diabetics is
unknown
- Myocardial perfusion study (MPS) is a non-invasive and
effective diagnostic method for CAD
- Which asymptomatic diabetics would benefit the most form
MPS is controversial.
- Type 2 diabetics with longer duration of diabetes,
smokers and insulin users are at greater risk of asymptomatic CAD