Comprehensive quantification of fuel use by the failing and nonfailing human heart

Metabolomics, at the heart With heart failure a leading cause of death, a better understanding of metabolic function in the heart is a welcome advance. Murashige et al. measured more than 270 metabolites using liquid chromatography–mass spectrometry in human blood samples taken from an artery entering the heart and from a vein leaving it. Differences thus reflected the metabolic processes at work in the heart. Their results confirmed that hearts voraciously consume fatty acids. Hearts secreted, rather than consumed, amino acids, thus revealing active proteolysis. In patients with heart failure, ketone and lactate consumption increased, as did proteolysis. These findings could lead to strategies for fighting heart disease by altering metabolism. Science , this issue p. 364