Original article Value of 99m Tc-methoxyisobutylisonitrile ( 99m Tc-MIBI) gated SPECT for the detection of silent myocardial ischemia in hemodialysis patients: clinical variables associated with abnormal test results Meltem Caglar a , Babak Mahmoudian a , Kudret Aytemir b , Serkan Kahraman c , Mustafa Arıcı c , Giray Kabakcı b and Erdem Karabulut d Background Although coronary artery disease is a major cause of mortality and morbidity in patients undergoing hemodialysis, there is no accurate diagnostic strategy for these patients. Aim To assess the value of 99m Tc-methoxyisobutylisonitrile ( 99m Tc-MIBI) gated single-photon emission computed tomography for the detection of silent myocardial ischemia in patients undergoing hemodialysis and to evaluate the clinical variables associated with abnormal test results. Methods Thirty-one asymptomatic patients undergoing hemodialysis (20 men, 11 women), with a mean age of 45 years (range, 25–75 years), were included in the study. Serum electrolytes, creatinine, homocysteine and adhesion molecules were measured prior to dialysis. Ambulatory blood pressure, carotid intima–media thickness measurements, echocardiography and stress 99m Tc-MIBI imaging were performed in all patients, whereas coronary angiography was performed only in patients with abnormal myocardial perfusion scintigraphy and/or echocardiography. Results Gated myocardial perfusion scintigraphy results were abnormal in nine patients (29%) and coronary angiography was abnormal in six patients. After a median follow-up of 20 months (range, 14–28 months), nine patients experienced a cardiac event. Seven of the nine patients (78%) with abnormal myocardial perfusion scintigraphy suffered a cardiac event, compared with only two of 22 patients (9%) with normal myocardial perfusion scintigraphy (P < 0.0001). Patients with abnormal perfusion scintigraphy had higher serum C-reactive protein, homocysteine and adhesion molecule levels and the duration of hemodialysis was significantly longer. Conclusion In asymptomatic hemodialysis patients, gated myocardial perfusion scintigraphy is a safe and non-invasive screening technique for the detection of coronary artery disease and for predicting future cardiac events. The presence of ischemia correlates significantly with markers of inflammation. The discordant results (abnormal myocardial perfusion scintigraphy/normal coronary angiography) can be attributed to angiographically unrecognized occult atherosclerotic changes and abnormal vasodilatation capacity of the coronary circulation. Nucl Med Commun 27:61–69  c 2006 Lippincott Williams & Wilkins. Nuclear Medicine Communications 2006, 27:61–69 Keywords: coronary artery disease, hemodialysis, myocardial perfusion scintigraphy, silent ischemia, 99m Tc-MIBI Departments of a Nuclear Medicine, b Cardiology, c Internal Medicine Division of Nephrology and d Biostatistics, Hacettepe University Medical Faculty, Ankara, Turkey. Correspondence to Professor Meltem Caglar MD, Department of Nuclear Medicine, Hacettepe University Medical Faculty, Sıhhıye, Ankara 06100, Turkey. Tel: 90 312 448 0810; fax: 90 312 309 3508; e-mail: caglarm@hacettepe.edu.tr Received 14 July 2005 Accepted 5 October 2005 Introduction Cardiovascular disease (CVD) has been reported to account for more than one-half of all deaths in patients on hemodialysis [1–3]. The high prevalence of diabetes and hypertension contributes to the accelerated rate of CVD, in addition to uremia-related risk factors which play a role in the development of atherosclerosis. The mechanism of atherogenesis is complex and includes hypertension, smoking, hyperlipidemia, thrombogenesis and the production of vasoactive substances, growth factors, mediators of inflammation, soluble adhesion molecules, hyperhomocysteinemia and abnormal mineral metabolism [4–6]. The diagnosis of coronary artery disease (CAD) by clinical symptoms is unreliable as a considerable number of patients are asymptomatic. Silent myocardial ischemia has been reported in 25% of chronic hemodialysis patients, defined as the presence of ST segment depression without associated chest pain [7]. The diagnostic value of exercise tests is limited, because the interpretation of electrocardiogram (ECG) findings is hampered in the presence of left ventricular hypertrophy, electrolyte disorders and medications. Furthermore, patients on hemodialysis frequently are unable to complete a maximal test due to anemia, debility, peripheral vascular disease or poor physical condition. 0143-3636  c 2006 Lippincott Williams & Wilkins Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.