A high-fat diet in ischemic swine hearts improved systolic and diastolic performance, including higher ejection fraction (P=0.03) and greater resting perfusion (P=0.004) compared to a normal diet.
RCT (n=20)
randomized
Does a high-fat diet improve myocardial function and perfusion in a swine model of chronic myocardial ischemia?
A high-fat diet enhances myocardial function and perfusion in ischemic swine hearts through metabolic rewiring, providing a potential mechanism for the short-term adaptive phase of the obesity paradox.
AbstractBackground The effect of a high-fat diet on ischemic heart disease remains debated, with some studies suggesting paradoxical benefits. We investigated the direct myocardial effects of a high-fat diet in chronic ischemia using a clinically relevant swine model with integrated functional and proteomic assessment. Methods Twenty juvenile Yorkshire swine were randomized to a normal diet (n = 9) or high-fat diet (n = 11) for 5 weeks before placement of an ameroid constrictor on the left circumflex artery. The swine were then maintained on the assigned diet for 7 additional weeks. Terminal studies included pressure-volume hemodynamics, microsphere-derived myocardial perfusion, and proteomic profiling of ischemic and non-ischemic myocardium. Results High-fat diet swine developed a swine-specific, metabolic syndrome-like lipid phenotype: markedly elevated total cholesterol and low-density lipoprotein, increased high-density lipoprotein, and low/variable triglycerides, despite similar body mass index. Compared with the normal diet swine, the high-fat diet animals demonstrated higher ejection fraction (P = .03), preload recruitable stroke work (P = .02), and lower tau (P = .001), reflecting improved systolic and diastolic performance. Perfusion to ischemic myocardium was greater at rest (P = .004) and pacing (P = .0048). Proteomics (2,782 proteins) revealed upregulation of fatty acid metabolism and mitochondrial transport with downregulation of cytoskeletal pathways, indicating metabolic remodeling toward lipid utilization. Conclusions A high-fat diet enhances function and perfusion in ischemic swine hearts through metabolic rewiring, supporting the short-term adaptive phase of the obesity paradox while underscoring the need to define long-term consequences.
Hamze et al. (Tue,) conducted a rct in chronic myocardial ischemia (n=20). High-fat diet vs. Normal diet was evaluated on Myocardial function (ejection fraction, preload recruitable stroke work, tau) and perfusion. A high-fat diet in ischemic swine hearts improved systolic and diastolic performance, including higher ejection fraction (P=0.03) and greater resting perfusion (P=0.004) compared to a normal diet.