No abstract

Background The failing human heart is characterized by metabolic abnormalities, but these defects remains incompletely understood. In animal models of HF there is a switch from a predominance of fatty acid utilization to the more oxygen-sparing carbohydrate metabolism. Recent studies have reported decreases in myocardial lipid content, but inclusion of diabetics and nondiabetics obscures the distinction of adapations to metabolic derangements from adaptations to heart failure per se. Methods and Results We performed both unbiased and targeted myocardial lipid surveys using liquid chromatography-mass spectroscopy in non-diabetic, lean, predominantly non-ischemic advanced HF patients at the time of heart transplantation or LVAD implantation. We identified significantly decreased concentrations of the majority of myocardial lipid intermediates, including long-chain acylcarnitines, the primary subset of energetic lipid substrate for mitochondrial fatty acid oxidation. We report for the first time significantly reduced levels of intermediate and anaplerotic acyl-CoA species incorporated into Krebs cycle, while the myocardial concentration of acetyl-CoA was significantly increased in end-stage heart failure. In contrast, we observed an increased abundance of ketogenic β-hydroxybutyryl CoA, in association with increased myocardial utilization of β-hydroxybutyrate. We observed a significant increase in the expression of the gene encoding succinyl-CoA: 3oxoacid-CoA transferase (SCOT), the rate limiting enzyme for myocardial oxidation of βOHB and acetoacetate. Conclusions These findings indicate increased ketone utilization in the severely failing human heart independent of diabetes, support the role of ketone bodies as an alternative fuel and myocardial ketone oxidation as a key metabolic adaptation in the failing human heart.

No abstract

In patients with heart failure, elevated jugular venous pressure and a third heart sound are each independently associated with adverse outcomes, including progression of heart failure. Clinical assessment for these findings is currently feasible and clinically meaningful.