Objectives: This study noninvasively examined total creatine (CR) of the myocardium in dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) using proton magnetic resonance spectroscopy ((1)H-MRS).
Background: Abnormalities in CR metabolism in failing hearts have been reported. A biochemical study suggested that myocardial metabolic changes are very similar in DCM and HCM despite the different heart failure (HF) mechanisms.
Methods: Using cardiac-gated (1)H-MRS with magnetic resonance image (MRI)-guided point-resolved spectroscopy (PRESS) localization, we quantitatively measured septal CR. Patients with either DCM (n = 11) or HCM (n = 7) and age-matched normal subjects (n = 14) were examined.
Results: Myocardial CR was significantly lower in DCM patients (16.1 +/- 4.5 micromol/g wet weight [range 10.2 to 22.9], p < 0.05) than that in subjects with normal hearts (27.6 +/- 4.1 micromol/g [range 21.4 to 36.2]). Myocardial CR in HCM patients (22.6 +/- 8.1 micromol/g [range 12.2 to 34.5]) was significantly lower than that in subjects with normal hearts (p < 0.05) but was significantly higher than that in DCM patients (p < 0.05). In 18 patients with either DCM or HCM, myocardial CR correlated positively with left ventricular ejection fraction (LVEF) (y = 0.22x + 9.8, r = 0.73, p = 0.0006) but correlated negatively with plasma B-type natriuretic peptide (BNP) levels (y = -0.012x + 22.4, r = -0.54, p = 0.022).
Conclusions: This study showed that (1)H-MRS can noninvasively detect CR depletion associated with the severity of HF in cardiomyopathy.