Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology PET Measurements of Myocardial Blood flow Post Myocardial Infarction: Relationship to invasive and cardiac magnetic resonance studies and potential clinical applications Henry Gewirtz, M.D. Department of Medicine (Cardiology Division), Massachusetts General Hospital, Harvard Medical School, Boston, MA Head shot of author required Institution Picture/Logo Copyright American Society of Nuclear Cardiology

Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology INTRODUCTION 1- Coronary microvascular and conduit vessel function is considered in the setting of acute and sub acute myocardial infarction 2- Role of quantitative PET measurements of myocardial blood flow (MBF) in delineating underlying pathophysiology and assisting in clinical decision making is discussed 3- Role both of invasive studies and cardiac magnetic resonance (CMR) imaging in assessing microvascular function, a key determinant of prognosis is reviewed 4- Optimal interpretation of quantitative PET MBF exam and potential clinical applications is considered in relation to quantitative data from invasive and CMR studies Copyright American Society of Nuclear Cardiology

Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology RESULTS Shown are myocardial blood flow responses (MBF;mean±SD) to dobtuamnine (DBTM) and adenosine (ADO) in myocardial segments defined by functional response to adenosine (≥2 ml/min/g = WNL). In normal segments MBF response to DBTM is ~ 70% that of ADO. Abnormal segments have reduced rest MBF compared with that of normal and steal (STL) and have blunted responses both to DBTM and ADO. Steal segments by definition exhibit reduced MBF versus rest with DBTM and ADO, though ~36% less with DBTM. Data from Skopicki H, et al: Circulation. 1997;96(10):3346-3352 Copyright American Society of Nuclear Cardiology

Journal of Nuclear Cardiology | Official Journal of the American Society of Nuclear Cardiology CONCLUSIONS 1- PET MBF studies must use quantitative measurements of absolute MBF, rest and stress to best guide clinical management and provide prognostic information for patients with recent ACS (as well as chronic disease). 2- Though CFR/MPR provides useful prognostic information in stable patients with known or suspected IHD, IMR/HMR have proved more informative in the acute or sub acute post MI setting. None of these metrics are available from qualitative visual assessment of summed PET myocardial retention images. 3- PET quantitative measurements of MBF are required to identify potentially high risk pathophysiology such as coronary steal and more generally patients at increased risk of cardiac death or myocardial infarction who may benefit most from coronary revascularization. Copyright American Society of Nuclear Cardiology