Characterization of a highly effective preparation for suppression of myocardial glucose utilization

Background With appropriate protocols, F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) can visualize myocardial inflammation. Optimal protocols and normative myocardial FDG uptake values are not well-established. Methods We evaluated 111 patients referred for inflammation cardiac FDG PET/CT. Patients followed a low-carbohydrate, high-fat diet for 36 hours before imaging and received unfractionated heparin. Glucose and fatty acid metabolism biomarkers were obtained. Mean blood pool and maximum myocardial uptake (SUVmean, SUVmax) were measured, avoiding areas of abnormal FDG uptake or spillover. Results Adequate suppression of myocardial FDG uptake occurred in 95% of patients (n = 106). Myocardial SUV(max)was significantly below background blood pool SUVmean: septal myocardial to blood pool ratio 0.75 (95% CI 0.73-0.77;P < 0.001); lateral myocardial to blood pool ratio 0.70 (95% CI 0.68-0.72;P < 0.001). Glucose, insulin, and C-peptide correlated to blood pool SUVmean(Spearmanr(s) = 0.39,P < 0.01;r(s) = 0.40,P < 0.01;r(s) = 0.35,P < 0.01) and myocardial SUVmax(Spearmanr(s) = 0.31,P < 0.01;r(s) = 0.31,P < 0.01;r(s) = 0.26,P < 0.01). Fatty acid metabolism biomarkers did not correlate to myocardial SUVmax. Conclusions Patients following intensive metabolic preparation have myocardial FDG SUV(max)below background SUVmean. Biomarkers of glucose metabolism modestly correlate to FDG uptake.