Assessment of myocardial creatine concentration in dysfunctional human heart by proton magnetic resonance spectroscopy.

Creatine depletion in the non-viable infarcted human heart was previously demonstrated with proton magnetic resonance (MR) spectroscopy (1H MRS). In the present study, we assessed total creatine (CR) in human hearts with non-ischemic dysfunctions such as cardiomyopathy. Using cardiac-gated 1H MRS with MR image-guided PRESS localization, we measured septal CR in healthy and diseased human hearts. Fifteen patients with chronic heart failure (CHF, left ventricular ejection fraction < 45%) and 14 age-matched normal subjects were examined. Myocardial CR was significantly (p < 0.001) lower in failing hearts (15.1+/-SD 5.0 micromol/g wet weight, range 8.0-22.9) than in normal hearts (27.6+/-4.1 micromol/g wet weight, range 20.8-36.2). Myocardial CR concentrations in six heart failure patients with plasma B-type natriuretic peptide (BNP) levels of > 200 pg/ml (11.5+/-0.9 micromol/g wet weight, range 9.9-12.3) were significantly lower than those in four heart failure patients with plasma BNP levels of < 200 pg/ml (19.8+/-2.5 micromol/g wet weight, range 17.7-22.9, p < 0.001). Thus, our study showed that myocardial CR was decreased in non-ischemic dysfunctional hearts. Noninvasive measurements of myocardial CR by 1H MRS may be useful in the assessment of the severity of heart failure.