Effects of remote ischemic conditioning on myocardial perfusion, myocardial viability, left ventricular function and remodeling in pigs with acute myocardial infarction evaluated by serially gated 99mTc-MIBI SPECT/CT and 18F-FDG PET/CT

220 Objectives: We aim to address regional cardiac alterations assessed by radionuclide imaging with radiopharmaceuticals targeting different molecular processes to predict the dynamics of left ventricular (LV) remodeling following acute myocardial infarction (AMI) in Chinese mini-pigs. Methods: AMI was induced by placing an embolus into 1 to 2 mm under the first anterior descending branch in 10 animals. In the experimental group, remote ischemic conditioning was induced in pigs by blood pressure inflation on the lower limbs for 5-min period and 4 cycles after AMI. A series of gated 99mTc-MIBI myocardial perfusion SPECT/CT (G-SPECT) imaging and gated 18F-FDG (3.89 ± 0.4MBq) PET/CT imaging (G-PET) were performed longitudinally at 3rd, 14th and 28th day after AMI. Total perfusion defect (TPD, %), hibernating myocardium (HM, %), scar myocardium (%), LV global function (LVEF, %), LV remodeling (EDV, ESV) and regional function (wall motion and wall thickening) were calculated and analyzed. One-way ANOVA was used to compare the significance of differences of various parameters at different time points (P <0.05), all parametric data were expressed as mean ± SD. Results: One pig absenting AMI and one pig died 14th day after surgery were excluded. A total of 8 pigs (34.0±1.7kg) were finally assessed. As shown in Table 1, in the experimental group (n=5), both TPD (44.2 ± 7.0%, 20.6 ± 8.9%, 19.8 ± 5.0%, P 0.05). Both SMS and STS decreased on 14th day whereas subsequently increased on 28th day (P>0.05). In the control group (n=3), both ESV (22.7 ± 7.5mL, 32.3 ± 8.5mL, 36.0 ± 10.1mL, P 0.05). Conclusions: Remote ischemic conditioning was a simple technique which has a specific protective effect on the AMI model. It could improve LV function in the subacute phase and prevent the development of LV remodeling. Acknowledgements: This project was sponsored by the National Natural Science Foundation of (81871377, 81571717), Capital Characteristic Clinical Application Research (Z181100001718071).