Prognostic significance of cerebral metabolic abnormalities in patients with congestive heart failure

Background - Cerebral metabolic abnormalities were proposed as a potential marker of disease severity in congestive heart failure (CHF), but their prognostic significance remains uncertain. Methods and Results - We investigated the prognostic value of cerebral metabolic abnormalities in 130 consecutive patients with advanced CHF (100 men aged 42.6±11.9 years; left ventricular ejection fraction, 22.2±6.2%). Proton magnetic resonance spectroscopy data were obtained from localized regions (≈8 mL) of the occipital gray matter and the parietal white matter. The primary end point was the occurrence of death after the proton magnetic resonance spectroscopy. During follow-up (18.5±14.4 months), 21 patients died and 15 underwent urgent heart transplantation. In the Cox proportional model, occipital metabolites (N-acetylaspartate, creatine, choline, and myoinositol), parietal N-acetylaspartate level, and the duration of CHF symptoms (> 12 months) were validated as univariate predictors of death. In multivariate Cox analyses, however, the occipital N-acetylaspartate level was an independent predictor of death (hazard ratio, 0.52; 95% CI, 0.41 to 0.67; P<0.001). An analysis with respect to the combined end point of death or urgent transplantation showed similar results. The best cutoff value (9.0 mmol/kg) for occipital N-acetylaspartate level had 75% sensitivity and 67% specificity to predict mortality. Conclusions - The occipital N-acetylaspartate level is a powerful and independent predictor of CHF mortality, suggesting that cerebral metabolic abnormalities may be used as a new prognostic marker in the assessment of patients with CHF.