Evaluation of myocardial glucose metabolism in hypertrophic cardiomyopathy using 18F-fluorodeoxyglucose positron emission tomography

BACKGROUND The purposes of this study were to assess the usefulness of myocardial 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for evaluating myocardial metabolic status in hypertrophic cardiomyopathy (HCM) and the therapeutic efficacy of alcohol septal ablation (ASA) in hypertrophic obstructive cardiomyopathy (HOCM). METHODS Thirty HCM patients (64.4±10.5 years, 14 male, 12 hypertrophic non-obstructive cardiomyopathy [HNCM], 16 HOCM, and 2 dilated phase of HCM) underwent 18F-FDG-PET/CT. 18F-FDG uptake was semi-quantitatively evaluated using an uptake score in each 17 segment and the entire LV or regional standardized uptake value (SUV). RESULTS 18F-FDG uptake was observed mostly in a hypertrophied myocardium in HNCM patients, whereas 18F-FDG was extensively accumulated beyond the hypertrophied myocardium in HOCM patients. There was a positive correlation between the summed uptake score of 18F-FDG and high-sensitive troponin T level in HNCM patients (r = 0.603, p = 0.049), whereas the score was positively correlated with brain natriuretic peptide level (r = 0.614, p = 0.011) in HOCM patients. In 10 patients who received ASA, the maximum SUV of the entire LV was significantly reduced from 5.6±2.6 to 3.2±2.1 (p = 0.040) after ASA. Reduction of that maximum SUV was particularly significant in the lateral region (from 5.5±2.6 to 2.9 ±2.2, p = 0.024) but not significant in the anteroseptal region (from 4.5±2.6 to 2.9±1.6, p = 0.12). CONCLUSION Extensive 18F-FDG uptake beyond the hypertrophied myocardium was observed in HOCM. ASA attenuates 18F-FDG uptake in a remote lateral myocardium.