Evaluation of Coronary Artery Disease with Tc-99m Tetrofosmin SPECT in Conjuction with Intravenous Adenosine

Hwang, Jin Yong; Lee, Jaetae; Choi, Ji Yong; Ahn, Byeong Cheol; Cho, Yong Keun; Chae, Shung Chull; Jun, Jae Eun; Park, Wee Hyun; Lee, Kyu Bo; Kim, Yoon Nyun; Cho, In Ho

Abstract

BACKGROUND: Tc-99m tetrofosmin is a recently developed myocardial perfusion agent that has shown promising characteristics, displaying rapid accumulation in and slow clearance from the myocardium with rapid clearance from background organs. Adenosine is relatively safe, direct and potent coronary vasodilator and has been used as a stress agent in myocardial perfusion scintigraphy. We have performed tetrofosmin single photon emisson computed tomography(SPECT) in patients suspected of coronary artery disease. This study was aimed to assess the safety profile and diagnostic accuracy of adenosine Tc-99m tetrofosmin SPECT. METHOD: One hundred forth six patients underwent Tc-99m tetrofosmin SPECT with intravenous adenosine. Four hours after resting Tc-99m tetrofosmin SPECT imaging, adenosine was infused intravenously at a dose of 0.14 mg/kg of body weight per minute for 6 min and Tc-99m tetrofosmin was injected at 3 min after start of infusion. Blood pressure, heart rate and side effects was recorded during and after four minites of adenosine infusion. Forty seven of patients underwent coronary angiography within 2 weeks.
RESULTS
Adenosine induced a significant and mild decrease in systolic and diastolic blood pressure at 2 min after start of adenosine infusion and a significant and mild increase in heart were observed in 70% of 146 patients. Chest discomfort(30%), mild dyspea(25%), chest pain(19%), and headach(12%) were common. No serious side effects were observed despite of continuation chest pain and restlessness, respectively. The diagnostic sensitivity for detection of CAD(>/=50% and >/=70% coronary stenosis by coronary angiography) by adenosine Tc-99m tetrofosmin SPECT were sensitivity 92%, 97%, and specificity) were 76%, 79% for LAD, 67%, 67% for LCX, and 73%, 82% for RCA, respectively. Specificities were 92%, 89% for LAD, 100%, 100% for LCX, 92%, and 87% for RCA.
CONCLUSION
Adenosine Tc-99m tetrofosmin SPECT appears to be a feasible, safe, highly sensitive and specific test for the diagnosis of coronary artery disease.