Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy

OBJECTIVES Using proton magnetic resonance spectroscopy we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. BACKGROUND Few data are available about cerebral metabolism in CHF. METHODS Fifty patients with CHF (ejection fraction less than or equal to 35%) and 20 healthy volunteers were included for this study. Of the patients, 10 patients underwent heart transplantation. ALL subjects performed symptom-limited bicycle exercise test. Proton magnetic resonance spectroscopy (H-1 MRS) was obtained from localized regions (8 to 10 mi) of occipital gray matter (OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. RESULTS In PWM only creatine level was significantly lower in CHF than in control subjects, bur in OGM all four metabolite levels were decreased;in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p < 0.05), and with peak oxygen consumption and serum sodium concentration in OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. CONCLUSIONS This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity. (C) 1999 by the American College of Cardiology.