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

BACKGROUND: The purposes of this study were to assess the usefulness of myocardial (18)F-fluorodeoxyglucose ((18)F-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 (18)F-FDG-PET/CT. (18)F-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: (18)F-FDG uptake was observed mostly in a hypertrophied myocardium in HNCM patients, whereas (18)F-FDG was extensively accumulated beyond the hypertrophied myocardium in HOCM patients. There was a positive correlation between the summed uptake score of (18)F-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 (18)F-FDG uptake beyond the hypertrophied myocardium was observed in HOCM. ASA attenuates (18)F-FDG uptake in a remote lateral myocardium.