Evaluation of myocardium metabolism by PET-CT on hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy is defined as the presence of increased left ventricle (LV) myocardial wall thickness (MWT) not solely explained by loading conditions. Myocardial metabolism can be assessed by PET-CT with 2-[18F]FDG. The purpose of this study was to assess myocardial LV wall metabolism and features related with non-obstructive HCM with normal LV ejection fraction, namely, MWT, left atrium volume (LAV) and biochemical markers of LV dysfunction (NT-proBNP) and the score of sudden cardiac death (SCD) Methods and Results Thirty patients were recruited with an age of 54.4±11.3, 60% males and with a MWT of 20.3±4.3 and an LAV of 46.1±16.5 and a NT-proBNP of 661.2±724.2. PET-CT was performed in a Biograph Vision 600, Siemens and to suppress physiologic 2-[18F]FDG cardiac uptake, a 2 day high-fat/low-carbohydrate diet and a 12 hours overnight fast were prescribed. Increased 2-[18F]FDG myocardial uptake (increased metabolism) was considered when above the vascular activity (threshold ≥ 1) and presented as a percentage of LV myocardium. Areas of increased metabolism were seen in 60% of the patients with an extension of 19.1± 24.0. MWT, LAV and NT-proBNP were significantly correlated with 2-[18F]FDG uptake with a correlation coefficient of 0.39 (p=0.03) 0.43 (p=0.02), 0.51(p=0.01), respectively. Conclusions Increased metabolism in the wall of the LV seems to have a role on phenotype expression of the disease and on myocardial dysfunction