Utility of positron emission tomography in predicting improved left ventricular ejection fraction after coronary artery bypass grafting among patients with ischemic cardiomyopathy

The objective of this study was to determine whether preoperative estimates of regional myocardial uptake of (18)-F-fluorodeoxyglucose (FDG) could pre dict postoperative improvement in ejection fraction in patients undergoing coronary artery bypass grafting (CABG) for ischemic cardiomyopathy. 20 cons ecutive patients [left ventricular ejection fraction (LVEF) less than or eq ual to 27%] were referred for preoperative positron emission tomography (PE T) to measure regional myocardial FDG uptake and were deemed candidates for CABG. All individuals had technically adequate vessels and significant via bility. The left anterior descending (LAD) coronary artery was severely dis eased in all patients. Because of the importance of the anterior wall to ov erall ventricular performance, FDG uptake was semiquantitated in those regi ons and related to postoperative LVEF. 17 patients underwent CABG with an u neventful recovery. LVEF increased from 22 +/- 4 to 26 +/- 7% 2 weeks posts urgery (p < 0.05), with greater than or equal to 5% change noted in 7 patie nts (group 1) and < 5% noted in 10 patients (group 2). No preoperative or p erioperative clinical variable could predict those with improved ventricula r function. The relative amount of FDG uptake in the anterior wall was high er in group 1 compared with group 2 (93 +/- 9 vs. 81 +/- 13%; p < 0.05) and correlated with the change in LVEF post-CABG (r = 0.50; p < 0.05). > 88% o f FDG uptake in the LAD region had a positive predictive accuracy of 67% an d negative predictive accuracy of 88% for improved LVEF postbypass. Late fo llow-up estimates of LVEF (median of 10 months) showed that early changes i n function were sustained. In summary, among patients with severe coronary artery disease and depressed LVEF, ventricular function may improve early p ostrevascularization. PET estimates of relative FDG uptake in the anterior wall help predict those individuals who are likely to have the greatest inc rement in LVEF. Copyright (C) 2000 S. Karger AG, Basel.