Myocardial Perfusion Scintigraphy in Detection of Myocardial Ischemia and Therapy Planning in Early Stages of Diabetes Mellitus

Summary Patients with diabetes mellitus (DM) develop complications including coronary artery disease (CAD), which is the leading cause of mortality in this group of patients. One of the diagnostic modalities for early detection of myocardial ischemia in symptomatic and asymptomatic patients with DM is myocardial perfusion tomography (MPI). The aim of this study was to determine the usefulness of MPI in detection of myocardial ischemia in symptomatic and asymptomatic patients in early stages of DM. Thirty-four patients with DM, aged from 24 to 65 years, nine women and fifteen men were examined. Thirteen patients were CAD symptomatic, and 21 were asymptomatic. MPI was performed through a standard two-day protocol, and findings were categorized as normal perfusion, reversible perfusion defect (ischemia), and fixed perfusion defect (scar). Patients with ischemia were elected for coronary angiography (CAG). MPI and CAG findings were statistically analyzed. Fifteen (44,12%) patients had normal left ventricle perfusion, while 19 (55,88%) patients had perfusion defects. Scar was found in one patient, and ischemia in 18 patients. CAG showed stenosis of coronary artery in 7 (36,84%) of 19 patients with perfusion defects on MPI. Statistical analysis showed no correlation between MPI ischemia and stenosis on CAG. Discrepancy between ischemia on MPI and CAG presentations of epicardial coronary arteries is related to endothelial dysfunction rather than atherosclerosis. These patients benefit more from pharmacological therapy than from revascularization. MPI and CAG should be reserved for individuals with high risk of CAD.

Detection of doxorubicin cardiotoxicity in patients with breast cancer by 99mTc-MIBI myocardial perfusion tomography

10775 Background: Cardiotoxicity is a well-known side effect of several cytotoxic drugs especially of the anthracyclines and can lead to long term morbidity. Endomyocardial biopsy is the only specific test for early diagnosis of anthracycline-induce toxicity. Efforts are continuing on finding a more sensitive and reliable predictor of eventual clinic cardiac dysfunction. Therefore, it is crucial that careful monitoring to identify those patients patients who are at risk of developing unpredectible and some times-irreversible dysfunction. Serial measurement of left ventricular ejection fraction by radionuclide angiography remains a useful and widely adopted modality in monitoring patients that are receiving doxorubicin. Objective: To investigate the value of 99mTc-MIBI myocardial perfusion tomography to detect myocardial damage in patients with breast cancer under chemotherapy. Methods: Thirty patients were examined from May to December 2000 by electrocardiogram (ECG), nuclear angiography for detecting left ventricular ejection fraction (LVEF) and 99mTc-MIBI myocardial perfusion was performed before chemotherapy and after chemotherapy. Results: Fifteen patients were treated by continuos infusion over 24 hr, nine patients over 48 hr and 6 patients were treated by bolus. The patients presented with a decrease of > or = 9% in absolute ejection fraction at 200–320 mg/m2 with 99mTc-MIBI and 5% with nuclear angiography. Gated myocardial perfusion scintigraphy results were abnormal in four patients (12.9%). All patients were treated by continuos infusion and the radiotherapy was absent. Other factors were investigated: hypertension, diabetes, smoker and obesity. Conclusions: 99 mTc-MIBI studies are helpful in the assessment of doxorubicin cardiotocixity. Anthracyclines induced myocite injury symptomatic or asymptomatic; uptake at intermediate cumulative doses identifies patients at risk of cardiotoxicity before ejection fraction deteriorates. The 99-mTc-MI BI imaging may be a sensitive method for non invasive visualization of myocardial cell damage and useful in the early diagnosis of specific heart muscle disease. Doxorubicin cause silent myocardial ischemia. No significant financial relationships to disclose.