RT Journal Article SR Electronic T1 Reduced Oxidative Metabolic Response in Dysfunctional Myocardium with Preserved Glucose Metabolism but with Impaired Contractile Reserve JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1885 OP 1891 VO 45 IS 11 A1 Keiichiro Yoshinaga A1 Chietsugu Katoh A1 Rob S.B. Beanlands A1 Kazuyuki Noriyasu A1 Kaoru Komuro A1 Satoshi Yamada A1 Yuji Kuge A1 Koichi Morita A1 Akira Kitabatake A1 Nagara Tamaki YR 2004 UL http://jnm.snmjournals.org/content/45/11/1885.abstract AB The recovery of function in myocardium defined as viable by 18F-FDG PET may differ from that defined by dobutamine stress echocardiography (DSE). The aim of this study was to investigate the difference in the oxidative metabolic response between myocardial segments with preserved contractile reserve (CR) and those without CR, in segments with and without preserved glucose metabolism (GM), using 11C-acetate PET. Methods: Twenty patients with previous myocardial infarction (left ventricular ejection fraction, 37.1% ± 16.5%) underwent dynamic 11C-acetate PET at rest and during dobutamine (7.5 μg/kg/min) infusion. GM was evaluated using 18F-FDG PET and CR was evaluated using DSE. Dysfunctional segments were divided into 3 groups: group A (n = 26) with preserved CR and GM, group B (n = 15) without CR but with preserved GM, and group C (n = 41) without CR and without preserved GM. Results: Resting oxidative metabolism (k mono = monoexponential clearance rate) was preserved in group A and group B (0.052 ± 0.011/min vs. 0.051 ± 0.012/min, P = not significant) but was reduced in group C (0.040 ± 0.015/min) (P < 0.03 vs. group A and group B). The change in k mono, as a measure of the metabolic response to low-dose dobutamine, was significantly higher in group A (0.018 ± 0.012) than that in group B (0.0075 ± 0.0096, P < 0.03) and group C (0.0080 ± 0.012, P < 0.005). Conclusion: Viable segments based on 18F-FDG PET have preserved resting oxidative metabolism. However, segments without CR but with preserved GM show a reduction in the oxidative metabolic response to low-dose dobutamine infusion. The decrease in CR may be related to the reduction in the metabolic response to inotropic stimulation despite preservation of tissue viability on 18F-FDG PET.