Myocardial Uptake of 7′-(Z)-[123I]Iodorotenone During Vasodilator Stress in Dogs With Critical Coronary Stenoses
| Autor: | Mirta Ruiz, Alexis Broisat, Norman C. Goodman, George A. Beller, Denny D. Watson, David K. Glover, Bryan W. Reutter, Mustafa Janabi, Saul Schaefer, Henry F. VanBrocklin, Kathleen M. Brennan, Stephen M. Hanrahan |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Male
medicine.medical_specialty Adenosine A2 Receptor Agonists Critical Illness Hemodynamics Single-photon emission computed tomography Sensitivity and Specificity Article Coronary artery disease Iodine Radioisotopes Myocardial perfusion imaging Coronary circulation Random Allocation Dogs In vivo Internal medicine Coronary Circulation Rotenone Medicine Animals Radiology Nuclear Medicine and imaging Tomography Emission-Computed Single-Photon medicine.diagnostic_test business.industry Coronary Stenosis Blood flow medicine.disease Image Enhancement Disease Models Animal Thallium Radioisotopes medicine.anatomical_structure Cardiology Cardiology and Cardiovascular Medicine business Perfusion Echocardiography Stress |
| Popis: | Background— There is a well-recognized need for a new generation of single photon emission computed tomography (SPECT) perfusion tracers with improved myocardial extraction over a wide flow range. Radiotracers that target complex I of the mitochondrial electron transport chain have been proposed as a new class of myocardial perfusion imaging agents. 7-(Z)-[ 125 I]iodorotenone ( 125 I-ZIROT) has demonstrated superior myocardial extraction and retention characteristics in rats and in isolated perfused rabbit hearts. We sought to fully characterize the biodistribution and myocardial extraction versus flow relationship of 123 I-ZIROT in an intact large-animal model. Methods and Results— The 123 I-ZIROT was administered during adenosine A 2A agonist-induced hyperemia in 5 anesthetized dogs with critical left anterior descending (LAD) stenoses. When left circumflex (LCx) flow was maximal, 123 I-ZIROT and microspheres were coinjected and the dogs were euthanized 5 minutes later. 123 I-ZIROT biodistribution was evaluated in 2 additional dogs by in vivo planar imaging. At 123 I-ZIROT injection, transmural LAD flow was unchanged from baseline (mean±SEM, 0.90±0.22 versus 0.87±0.11 mL/[min · g]; P =0.92), whereas LCx zone flow increased significantly (mean±SEM, 3.25±0.51 versus 1.00±0.17 mL/[min · g]; P 123 I-ZIROT extraction tracked regional myocardial flow better than either thallium-201 or 99m Tc-sestamibi from previous studies using a similar model. Furthermore, the 123 I-ZIROT LAD/LCx activity ratios by ex vivo imaging or well counting (mean±SEM, 0.42±0.08 and 0.45±0.1, respectively) only slightly underestimated the LAD/LCx microsphere flow ratio (0.32±0.09). Conclusions— The ability of 123 I-ZIROT to more linearly track blood flow over a wide range makes it a promising new SPECT myocardial perfusion imaging agent with potential for improved coronary artery disease detection and better quantitative estimation of the severity of flow impairment. |
| Databáze: | OpenAIRE |
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