99 mTc-MIBI washout as a complementary factor in the evaluation of idiopathic dilated cardiomyopathy (IDCM) using myocardial perfusion imaging.

Rapid technetium-99 m methoxyisobutylisonitrile (99 mTc-MIBI) washout has been shown to occur in impaired myocardia. This study is based on the hypothesis that scintigraphy can be applied to calculate the myocardial 99 mTc-MIBI washout rate (WR) to diagnose and evaluate heart failure severity and other left ventricular functional parameters specifically in idiopathic dilated cardiomyopathy (IDCM) patients. Patients with IDCMP (n = 17; 52.65 ± 11.47 years) and normal subjects (n = 6; 49.67 ± 10.15 years) were intravenously administered 99 mTc-hexakis-2-methoxyisobutylisonitrile (99 mTc-MIBI). Next, early and delayed planar data were acquired (at 3.5-h intervals), and electrocardiogram (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT) was performed. The 99 mTc-MIBI WR was calculated using early and delayed planar images. Left ventricular functional parameters were also analyzed using quantitative gated SPECT (QGS) data. In target group, myocardial WRs (29.13 ± 6.68%) were significantly higher than those of control subjects (14.17 ± 3.31%; P < 0.001). The 99 mTc-MIBI WR increased with the increasing severity of the NYHA functional class (23.16 ± 1.72% for class I, 30.25 ± 0.95% for class II, 32.60 ± 6.73% for class III, and 37.50 ± 7.77% for class IV; P = 0.02). The WR was positively correlated with the end-diastolic volume (EDV) index (r (2) = 0.216; ß = 0.464; P = 0.02 [ml/m(2)], the end-systolic volume (ESV) index (r (2) = 0.234; ß = 0.484; P = 0.01 [ml/m(2)]), the summed motion score (SMS) (r (2) = 0.544; ß = 0.738; P = 0.00), and the summed thickening score (STS) (r (2) = 0.656; ß = 0.810; P = 0.00); it was negatively correlated with the left ventricular ejection fraction (LVEF) (r (2) = 0.679; ß = -0.824; P = 0.00). It can be concluded that 99 mTc-MIBI scintigraphy might be a valuable molecular imaging tool for the diagnosis and evaluation of myocardial damage or dysfunction severity.

Myocardial perfusion imaging using a technetium-99m sestamibi in asymptomatic and low risk for coronary artery disease patients with diagnosed systemic lupus erythematosus.

INTRODUCTION: The aim of the present study was to evaluate technetium-99m sestamibi single photon emission tomography (SPECT) myocardial perfusion imaging (MPI) and its association with some clinical and laboratory parameters in an asymptomatic systemic lupus erythematosus (SLE) population. MATERIALS AND METHODS: Twenty-one subjects with SLE and no suspected or documented coronary artery disease (CAD) accomplished myocardial perfusion imaging. Some SLE and CAD parameters were also evaluated in association with myocardial SPECT. RESULTS: Twenty-one women with a diagnosis of SLE (mean age 36.9 ± 12.8) entered the study. All patients were in the low-risk category for CAD pretest; however, abnormal myocardial perfusion results were found in eight (38%) patients. Amongst the traditional CAD risk factors, there was a significant association between the presence of dyslipidemia and myocardial perfusion abnormalities (P= 0.047). However, we found no significant association between other traditional and SLE-specific risk factors. CONCLUSION: This study's significant finding was that asymptomatic CAD is common in SLE patients, even in those thought to be low risk for CAD and in the absence of cardiac symptoms.