Table 1.

A brief summary of some of the main metabolic changes associated with HFpEF (in comparison with HFrEF). The detailed metabolic changes that occur in heart failure are complex, and are dependent not only on the severity and type of heart failure present, but also on the coexistence of common comorbidities such as obesity and type 2 diabetes, and reviewed in detail elsewhere [70]

Metabolic pathway	HFrEF	HFpEF
Fatty acid oxidation	Increased in humans, measured in vivo [51, 52]	Reduced in humans in vivo [51, 53, 54] and in rodents [55] measured via ex vivo Langendorff perfusion
Glucose oxidation	Reduced in mice, measured via ex vivo perfusion [56, 57]	Reduced in LV biopsy [58] from left-ventricular assist device (LVAD) patients with advanced HF and in rodents [59–61] measured via Langendorff perfusion
Glycolysis	Unchanged [62] or increased [63] in Langendorff-perfused rat heart	Increased in LVAD patients after biopsy [64]; also increased in rats [59].
Coupling between glucose oxidation and glycolysis	Unchanged in the perfused hearts of mice [56] or reduced in rats [63]	Reduced in human LVAD patients [64] and in mice [65].
Ketone body oxidation	Unknown, insufficient data	Increased in human advanced HF patients [66, 67] as determined either via biopsy at the time of LVAD implantation or transplantation
Branched chain amino acid metabolism	Unknown, insufficient data	Impaired in humans [68] and mice [68, 69] as measured via biopsy