Proximal coronary artery occlusion after distal ligation in pigs significantly reduced global LV ejection fraction compared to controls (39% vs 66%, P<0.05), establishing a model of chronic LV dysfunction.
A pig model of old myocardial infarction generated by chronic proximal coronary artery obstruction after distal ligation successfully produces chronic LV dysfunction and remodeling with high survival, which can be effectively evaluated using PET imaging.
Absolute Event Rate: 39% vs 66%
p-value: p=<0.05
UNLABELLED: A pig model of reduced left ventricular (LV) function and remodeling or chronic heart failure with long survival after myocardial infarction (MI) has not been established. The aim of this study was to evaluate the pathophysiologic status of a pig model of old MI using a series of PET studies. METHODS: Twenty-seven male farm pigs were divided into 2 groups: 7 animals in the control group and 20 animals that underwent a proximal coronary artery (CA) occlusion using an ameroid constrictor after distal CA ligation. A series of PET examinations was performed to assess LV volumes, LV functions, myocardial perfusion response to adenosine, and viability as water-perfusable tissue index. RESULTS: The distal CA ligation inhibited arrhythmia during and after the operation, and a transmural anteroseptal MI, with an infarction area of 27% ± 5% of the whole left ventricle, was generated with a survival rate of 75% at 4 mo. Wall motion evaluated by (18)F-FDG PET was diffusely reduced, including the noninfarcted wall. Global LV ejection fraction as assessed by gated C(15)O PET was reduced (39% ± 16%) in the group undergoing occlusion, compared with the control group (66% ± 16%, P < 0.05). LV end-systolic (31.4 ± 9.2 cm(3)) and end-diastolic (52.7 ± 10.2 cm(3)) volumes were increased, compared with controls (15.2 ± 9.4 cm(3), P < 0.01, and 41.7 ± 11.5 cm(3), P < 0.05, respectively). Histology showed hypertrophy and development of microscopic fibrosis in noninfarcted myocardium. PET demonstrated the reduced myocardial perfusion response to adenosine and also reduced water-perfusable tissue index in remote segments. CONCLUSION: The pig model of old MI generated by the chronic proximal CA obstruction after distal ligation was characterized by LV dysfunction and remodeling, with a high survival rate.
Teramoto et al. (2011) studied Old myocardial infarction with chronic left ventricular dysfunction (n=27). Proximal coronary artery occlusion using an ameroid constrictor after distal CA ligation vs. Control group was evaluated on Global LV ejection fraction (p=<0.05). Proximal coronary artery occlusion after distal ligation in pigs significantly reduced global LV ejection fraction compared to controls (39% vs 66%, P<0.05), establishing a model of chronic LV dysfunction.