Impact of Diabetes Mellitus on Prediction of Clinical Outcome After Coronary Revascularization by ¹⁸F-FDG SPECT in Patients with Ischemic Left Ventricular Dysfunction

Abstract

Nuclear imaging using ¹⁸F-FDG is an established method for the noninvasive assessment of myocardial viability. Data on the value of ¹⁸F-FDG imaging in patients with diabetes mellitus are scarce. The aim of this study was to assess whether, in patients with diabetes mellitus and ischemic left ventricular (LV) dysfunction, ¹⁸F-FDG imaging can predict improvement of LV function and heart failure symptoms after coronary revascularization. Methods: A total of 130 consecutive patients with ischemic LV dysfunction who were already scheduled for surgical revascularization were studied; 34 of the patients had diabetes mellitus. All patients underwent radionuclide ventriculography to assess left ventricular ejection fraction (LVEF), resting 2-dimensional echocardiography to identify dysfunctional myocardial tissue, and dual-isotope ¹⁸F-FDG/^99mTc-tetrofosmin SPECT after oral administration of acipimox. Nine to 12 mo after coronary revascularization, radionuclide ventriculography and echocardiography were repeated. An improvement in LVEF by at least 5% was considered significant. Results: ¹⁸F-FDG SPECT demonstrated that 610 (50%) of 1,212 dysfunctional segments were viable. Patients with and without diabetes mellitus had a comparable number of dysfunctional but viable segments per patient. Also, the number of patients with a substantial amount of dysfunctional but viable myocardium (≥4 viable segments) was comparable between the groups with and without diabetes mellitus. The presence of substantial viability on ¹⁸F-FDG SPECT was predictive of improvement in LVEF and heart failure symptoms postoperatively (sensitivity and specificity of 82% and 89%, respectively, in patients with diabetes and 83% and 93%, respectively, in patients without diabetes; not statistically significant). Conclusion: ¹⁸F-FDG SPECT is practical for routine assessment of myocardial viability in patients with ischemic LV dysfunction with or without diabetes mellitus. Patients with substantial myocardial viability on ¹⁸F-FDG SPECT have a high probability of improvement of LV function and symptoms after coronary revascularization, irrespective of the absence or presence of diabetes mellitus.