Materials and Methods
This was a cross-sectional study, conducted at the nuclear medicine
department of Shohada Tajrish hospital, Tehran, Iran. In total, 63
asymptomatic patients with type 2 DM, referred for check-up or
pre-operative cardiac evaluation entered the study. An ethical approval
was obtained from Shahid Beheshti Medical University Ethics committee.
Patients were interviewed on the appointed scanning day and informed
about the goals of study in detail. A written informed consent was
obtained from all patients before enrolment. The inclusion criteria were
patients with proven T2DM, aged 35-80 years, ejection fraction (EF)
> 50%, normal ECG and life expectancy of more than one
year. Patients with any history of valvular heart disease, ischemic
heart disease, abnormal renal or hepatic failure, coronary intervention,
arrhythmia, perfusion defect on prior MPI scans or wall motion
abnormality on prior gated stress SPECT-MPI were excluded. Demographic
characteristics of participants were documented in a questionnaire. All
patients underwent a two-day rest/stress 99mTc-MIBI gated MPI SPECT,
according to the European Association of Nuclear Medicine (EANM)
guidelines for MPI scan (13). The rest scan was performed 60 minutes
after IV injection of 555 MBq 99mTc-sestamibi. On the day after,
myocardial stress was achieved by exercise (Bruce protocol) or
Dipyridamole (0.14mg/kg/min over 4 minutes), with 740 MBq
99mTc–sestamibi injected at peak stress. All patients consumed 120 mL
whole milk 10 minutes after tracer injection, as per routine. Imaging
was performed in both supine and prone positions. SPECT images were
acquired with a variable angle dual head Evo-Voxel Siemens gamma camera
(64 projections; 25 seconds/projection, matrix 64 * 64, zoom of 1.46,
8-frame gated study, low-energy high resolution collimator, in a
noncircular orbit). The images were processed using QPS/QGS and 4DM
software and the results were interpreted by a nuclear medicine
specialist.