Cardiovascular magnetic resonance detects the progression of impaired myocardial perfusion reserve and increased left-ventricular mass in mice fed a high-fat diet

Impaired myocardial perfusion reserve (MPR) is prevalent in obesity and diabetes, even in the absence of obstructive coronary artery disease (CAD), and is prognostic of adverse events. We sought to establish the time course of reduced MPR and to investigate associated vascular and tissue properties in mice fed a high-fat diet (HFD), as they are an emerging model of human obesity, diabetes, and reduced MPR without obstructive CAD. C57Bl/6 mice fed a HFD or a low-fat diet (control) were imaged at 6, 12, 18 and 24 weeks post-diet. The cardiovascular magnetic resonance (CMR) protocol included multi-slice cine imaging to assess ejection fraction (EF), left-ventricular (LV) mass, LV wall thickness (LVWT), and LV volumes, and first-pass perfusion CMR to quantify MPR. Coronary vascular reactivity, aortic atherosclerosis, myocardial capillary density and tissue fibrosis were also assessed. Body weight was increased in HFD mice at 6-24 weeks post-diet (p