Clinical importance of viability assessment in chronic ischemic heart failure

Background and hypothesis: Revascularization has provided an effective treatment of depressed left ventricular function in patients with chronically ischemic or “viable” myocardium. Assessment of viable myocardium can be achieved by several noninvasive techniques including dobutamine stress echo or radionuclides such as flurodeoxyglucose (F 18 DG). F 18 DG uptake studies are based on the assumption that enhanced glucose uptake in areas of diminished blood flow provides evidence of viable myocardium. To determine the clinical utility of viability assessment in the management of chronic ischemic left ventricular dysfunction, we reviewed the findings and short‐term treatment of a series of patients referred for heart failure evaluation who had subsequent F 18 DG uptake scans. Methods: We retrospectively reviewed 59 consecutive F 18 DG viability studies in a series of patients who had documented coronary artery disease and depressed left ventricular function. Single photon emission computerized tomography (SPECT) with F 18 DG was performed in the patients and these images were compared to SPECT images of resting myocardial perfusion using thallium, sestamibi, or teboroxime. Clinical decisions based on the results of these scans were obtained from chart review. Thirty‐day mortality was determined from chart review or contact with the patient's physician. The patients were divided into those without and with F 18 DG uptake consistent with viable ischemic myocardium. Further analysis included subgroups of patients who were advised to undergo transplantation, revascularization, or to continue medical therapy. Results: Of 34 patients referred for cardiac transplantation, 18 had viable myocardium and 13 underwent revascularization. In the entire study group, 34 of 59 (58%) had evidence of viable myocardium and 29 had subsequent revascularization procedures. Thirty‐day survival for all revascularization patients was 86%. Conclusion: Assessment of myocardial viability with F 18 DG SPECT imaging in patients with ischemic left ventricular dysfunction led to a clinical decision for revascularization in approximately half the patients with severe coronary disease and left ventricular dysfunction who were evaluated for myocardial viability in our institution.