Research has been conducted on the metabolic characteristics of the human heart, including how it utilizes energy substrates and undergoes metabolic remodeling. The studies appear to focus on both failing and non-failing hearts, with some investigations exploring specific conditions such as heart failure with preserved ejection fraction and Barth syndrome. The findings may provide new insights into the metabolic defects and characteristics of the human heart, potentially shedding light on novel metabolic pathways and biomarkers.