| Objective:To assess a new method to establish a pig model of left ventricular aneurysm(LVA) with left ventricular (LV) dysfunction and remodeling by gated 99mTc-MIBI SPECT perfusion (GSPECT) and gated 18F-FDG PET metabolic (GPET) imaging.Methods:Sixteen Chinese Mini-Pigs were included in our study and LV Aneurysm was induced by occlusion of left circumflex artery (LCX) and then placing an ameroid constrictor was placed at proximal left anterior descending artery (LAD). On the 4th week after surgery, total perfusion defect(TPD), percentage of viable myocardium (Mismatch), LV ejection fraction (LVEF), end diastolic volume (EDV) and end systolic volume (ESV) were evaluated by GSPECT and GPET. LV aneurysm was defined as with one or more dyskinetic or akinetic and wall thickening disappeared myocardial segments revealed by GPET.Results:The death rate of surgery was 31.2%(5/16), the survival rate was 100% (11/11) and 54.6%(8/11 Respectively on 1st and on 4th week. LV aneurysm was confirmed in eight pigs after imaging protocol by pathological results.Eight pigs performed GSPECT and GPET imaging and were divided into two groups according to imaging results on the 4th week after surgery. Comparing with myocardial infarction(MI) group, there was progressive increase in left ventricular end diastolic volume (LVEDV) and left ventricular end systolic volume (LVESV) at LV aneurysm group (P<0.05). LV ejection fraction (LVEF) and percentage of viable myocardium were significantly decreased at LV aneurysm group (P<0.05).Conclusion:Through GSPECT and GPET imaging,we found that ligation of the distal end of LCX and installation an ameroid constrictor at the proximal LAD play an important role in establishing LV aneurysm pig model, accompanied with obvious LV remodeling.Objective:The aim of this study was to evaluate the changes of global left ventricular (LV) function and LV remodeling by gated 99mTc-MIBI SPECT perfusion (GSPECT) and gated 18F-FDG PET metabolic (GPET) imaging during the period of LV aneurysm formation in pigs. Further, to analyze the relationship between the size of LV aneurysm with the severity of LV dysfunction and remodeling,and to analyze perfusion and glucose uptake in different region in ventricular aneurysm.Methods:A porcine model of left ventricular aneurysm was studied. On the 1st and 4th week after surgery, total perfusion defect (TPD) was evaluated by GSPECT, and LV ejection fraction (LVEF), end diastolic volume (EDV) and end systolic volume (ESV) were evaluated by GPET. LV aneurysm was defined as with one or more dyskinetic or akinetic myocardial segments revealed by GPET. Regional perfusion and glucose uptake were assessed by [99mTc]-sestamibi(MIBI)/[18F]-Fluorodeoxyglucose (FDG) on the 1st and the 4th week. Myocardial tissue in aneurysm/scar, border and remote regions were analyzed by Masson and HE staining.Results:Eleven pigs survived after surgeries. Eight pigs finished GSPECT and GPET imaging protocol and were divided into two groups according to the size of LV aneurysm on the 1st week after surgery. In group 1, a large size of LV aneurysm with> 3 segments was established in 4 pigs, and in group 2, a small size of LV aneurysm (<3 segments) was found in 2 pigs and no LV aneurysm were established in 2 pigs. With the time prolonged (on the 4th week), we found that TPD in group 1 was increased(P> 0.05), EDV and ESV were significantly increased(P< 0.05), and LVEF was gradually decreased (P< 0.05),perfusion and glucose uptake were decreased in aneurysm regions (P=0.144 and 0.123).However, glucose uptake appeared in significant decrease than perfusion in border regions(P=0.015 and 0.602).Ex vivo staining showed low content of viable myocardium both in scar and in border areas in large size group as an explanation for decreased perfusion as well as glucose uptake.In Group 2, TPD, EDV, ESV and LVEF remained stable(P> 0.05).For further analysis, perfusion and glucose uptake were increase in scar regions(all Ps>0.05).However,perfusion uptake were relatively stable while glucose uptake were mildly decreased in border area (all Ps>0.05).Masson and HE staining consistently revealed high content of viable myocytes in these areas.In addition, the size of LV aneurysm was significantly correlated with LVEF (r=-7.26, P<0.05), EDV (r= 0.855, P<0.01) and ESV (r= 0.825, P<0.01).Conclusions:(1) The size of LV aneurysm in the subacute stage may predictor LV dysfunction and remodeling in porcine models of left ventricular aneurysm. (2) In large size ventricular aneurysm animals,perfusion and glucose uptake in the border area appeared in stable in the subacute stage and then tended to be progressively worsen compared with the aneurysm regions, whereas such a trend was not observed in small size aneurysm animals.Objective:To evaluate the prognostic value of complete or incomplete revasculaization (RVS) in patients with coronary artery disease (CAD), referred by myocardial perfusion imaging (MPI) or by coronary angiography.Methods:Two hundred and two consecutive patients in Fuwai hospital who had myocardial ischemia revealed by 99mTc-MIBI MPI and treated by RVS were followed-up for 46 ± 21 months. Patients were categorized complete (CAGCR, n= 99) and incomplete (CAGIR, n= 103) RVS referred by CAG, and complete (MPICR, n= 112) and incomplete (MPIR, n= 90) correction of myocardial ischemia referred by MPI. Complete RVS referred by CAG was defined as all the diseased lesions treated by RVS successfully. Complete RVS referred by SPECT was defined as all the myocardial ischemia related vessels treated by RVS successfully. Death, nonfatal myocardial infarction (MI) and repeat RVS procedures were considered as major adverse cardiac events (MACE). All analyses were performed by SPSS 13.0, with p< 0.05 considered statistically significant.Results:The mortality of Group CAGCR was significantly lower than Group CAGIR [4/99 (4.0%) vs 12/103 (11.7%),P= 0.025], and but not for MACE[15/99 (15.4%) vs 19/103 (18.5%), P= 0.28] between two groups. Further, the mortality[4/112 (3.6%) vs 12/90 (13.3%), P= 0.005] and MACE rate [14/112 (12.6%) vs 20/90 (22.6%), P= 0.004] in Group MPICR was significant lower than those in the Group MPIIR. Multivariate Cox hazard regression analysis showed that ischemia related vessels untreated by RVS was one of the independent predictors for death (HR 4.02,95% CI: 1.13-12.55, P= 0.017) and the only independent predictor for MACE (HR 2.67,95% CI: 1.31-5.40, P= 0.006).Conclusion:In patients with CAD, RVS strategy not only should refer anatomic disease revealed by CAG, but more importantly, should correction myocardial ischemia identified by MPI.
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