ROLE OF TL-201 AND PET IMAGING IN EVALUATION OF MYOCARDIAL VIABILITY AND MANAGEMENT OF PATIENTS WITH CORONARY-ARTERY DISEASE AND LEFT-VENTRICULAR DYSFUNCTION

The reported mortality of patients with coronary artery disease (CAD) and congestive heart failure is high but variable. in the clinical man agement of these patients, the available treatment choices are medical therapy, cardiac transplantation and myocardial revascularization. My ocardial revascularization has become an attractive alternative in the management of patients with CAD and poor left ventricular function be cause medical therapy is associated with a high mortality and cardiac transplantation is expensive and not practical due to shortage of dono r hearts. Myocardial revascularization, however, should be recommended in those patients in whom the procedure is very likely to reverse reg ional and global left ventricular dysfunction and to improve heart fai lure symptoms and survival. Thallium-201 rest-redistribution myocardia l scintigraphy and PET imaging of myocardial perfusion and F-18-fluoro -deoxyglucose metabolism have been extensively evaluated for the asses sment of myocardial viability and for prediction of recovery of region al left ventricular dysfunction following myocardial revascularization ; with positive and negative predictive accuracies of 72% and 70% for (TI)-T-201 rest-redistribution imaging and 83% and 84% for perfusion-m etabolism PET imaging. Both modalities also are predictive of; improve ment in left ventricular ejection fraction after myocardial revascular ization. Patients with congestive heart failure who demonstrate the PE T pattern of mismatch are more likely to improve their heart failure s ymptoms following revascularization than those without the mismatch pa ttern. Furthermore, the PET pattern of mismatch identifies a subgroup of patients who are at very high risk for cardiac death on medical the rapy. Survival of these patients can be significantly improved by myoc ardial revascularization.