Abstract 157: A Highly Reproducible, Clinically Relevant Large Animal Model of Myocardial Ischemia and Heart Failure

Abstract

Background: Heart failure (HF) is the leading cause of mortality in United States. Animal models used to test novel HF therapeutics are inadequate as pathological features of human HF are not replicated. Available large-animal swine myocardial ischemia (MI) models mimic human HF; however, do not achieve ejection fractions (EF) less than 40%. Objective: We sought to develop a reproducible swine MI model with EF below 35%. Methods: Yucatan miniature pigs (n=18) were anesthetized, catheterized and collagen suspension (COL) of microfibrillar hemostat (INSTAT MCH, Ethicon) mixed in contrast and saline solution was injected into the left anterior descending coronary artery (LAD) under fluoroscopic guidance. COL injections started distally and filled side branches during catheter retraction. Complete transient LAD occlusion was confirmed at 2hrs by coronary angiography. Cardiac function was evaluated at 3mos using a 1.5T MRI System (Siemens Magnetom Avanto). LV volumes at end systole (LVESD) and diastole (LVEDD), EF, wall thickness (WT) in area at risk (AAR) and normal zones (NZ) were calculated. Uninjected Yucatan pigs (n=3) served as controls. Results: Twelve of 18 pigs survived COL infarction. At 3mos, EF was reduced in COL injected pigs compared to control (27.0±2.3 vs. 61.6±1.3%, respectively, P<0.001). LVESV and LVEDV were 4- and 2-fold higher and WT in AAR and NZ were reduced 6- and 2-fold, respectively in COL injected compared to controls. Conclusions: A reproducible large animal model of MI was produced by catheter based LAD collagen delivery resulting in EFs below 35% and progression to HF. By closely resembles human HF, it a highly useful for testing potential HF therapies.