Myocardial viability assessment and perioperative cardiovascular evaluation using single photon emission tomography and positron emission tomography

Nuclear cardiology including single photon emission computed tomography (SPECT) and positron emission tomography (PET) can play important roles as myocardial viability assessment and perioperative cardiovascular evaluation for noncardiac surgery. Increasing prevalance of coronary artery disease (CAD) is associated with an increasing number of patients with heart failure secondary to CAD. Three main therapies, medical, revascularizations, and heart transplantation, are currently available. Appropriate revascularization can improve left ventricular function, and hence could also improve an outcome. However, patients with reduced left ventricle (LV) function have higher perioperative cardiac risks. Therefore, it is important to evaluate the extent of myocardial viability to assist in deciding patient managements. In nuclear imaging, thallium-201 (201T1) SPECT, technetium-99m (99mTc) sestamibi SPECT, and 18F fluorodeoxyglucose (FDG) are applied for viability assessment. FDG is a glucose analogue and is used to measure myocardial glucose utilization. Among noninvasive imaging, FDG-PET is considered to be a standard measurement. Perioperative cardiovascular complications significantly deteriorate the outcome not only of the postoperative period but also over the subsequent 1 to 2 years. Intrathoracic noncardiac surgeries themselves are at intermediate or high perioperative risk. Thus, careful preoperative cardiac risk assessment is necessary for predicting cardiac complications. In the present review, we overview the present status of viability assessment and perioperative cardiovascular evaluation, and discuss some new approaches.