Myocardial triglyceride content in patients with left ventricular hypertrophy: comparison between hypertensive heart disease and hypertrophic cardiomyopathy

Proton magnetic resonance spectroscopy (H-1-MRS) enables the assessment of myocardial triglyceride (TG) content, which is reported to be associated with cardiac dysfunction and morphology accompanied by metabolic disorder and cardiac hemodynamic status. The clinical usefulness of myocardial TG content measurements in patients with left ventricular hypertrophy (LVH) has not been fully investigated. We examined whether myocardial TG content assessed by H-1-MRS was useful for diagnosis in patients with LVH. To quantify myocardial TG content, we conducted H-1-MRS in 35 subjects with LVH. Left ventricular function was measured by cardiac magnetic resonance imaging. Patients were assigned to a hypertensive heart disease (HHD, n = 10) or hypertrophic cardiomyopathy (HCM, n = 25) group based on the histology and/or late gadolinium enhancement pattern. The myocardial TG content was significantly higher in the HHD group than in the HCM group (2.14 +/- 1.29 vs. 1.09 +/- 0.72 %, P < 0.001). Myocardial TG content were significantly and negatively correlated with LV mass (r = -0.41, P < 0.04) and stroke volume (r = -0.64, P < 0.05) in the HCM group and HHD group, respectively. In a multivariate analysis, LV mass volume and diagnosis of HCM or HHD were independent factors of the myocardial TG content. The results suggest that myocardial metabolism may differ between HCM and HHD patients and that measurement of myocardial TG content by H-1-MRS may be useful for evaluating the myocardial metabolic features of LVH.