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Objective:To explore the changes of right ventricular myocardial perfusion in pulmonary arterial hypertension (PAH) pig models with a quantitative analysis technique based on dynamic SPECT myocardial perfusion imaging, and analyze the relationship between myocardial blood flow, hemodynamics and right ventricular function.Methods:Eleven Chinese miniature pigs (all males, 6-8 months old) weighing 25-30 kg were selected. The PAH models were established by ligating the main pulmonary artery and embolizing the right lower pulmonary artery. After the models were established, dynamic myocardial perfusion imaging with one-day resting/adenosine stress 99Tc m-methoxyisobutylisonitrile (MIBI) SPECT was performed, and the quantitative parameters of left and right ventricles were obtained, including stress myocardial blood flow (SMBF), rest myocardial blood flow (RMBF) and myocardial flow reserve (MFR: the ratio of stress to rest myocardial blood flow). Right heart catheterization was performed to evaluate the mean pulmonary arterial pressure (mPAP), and the right heart function index tricuspid annular plane systolic excursion (TAPSE) was measured by transthoracic echocardiography. According to TAPSE, animals were divided into right heart function preserved group ( n=5, TAPSE≥17 mm) and right heart dysfunction group ( n=4, TAPSE<17 mm). Pearson correlation analysis and the independent-sample t test were used for data analysis. Results:Nine experimental pig models were established with increased mPAP of (38.1 ± 11.6 ) mmHg (1 mmHg=0.133 kPa). Myocardial perfusion imaging showed clear radiotracer uptake in the right heart and myocardial hypertrophy. There was a significant positive correlation between right ventricular myocardial RMBF ((0.71±0.13) ml·min -1·g -1) and mPAP ( r=0.94, P< 0.001). The SMBF in the decreased right ventricular function group was significantly lower than that in the preserved right ventricular function group ((1.66±0.35) vs (2.24±0.30) ml·min -1·g -1;t=2.68, P=0.032). Conclusion:SPECT myocardial blood flow quantification can be used to evaluate the right ventricular myocardial blood flow in pig models of PAH.
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Objective:To assess the diagnostic value of ATP stress myocardial perfusion imaging(MPI) in detecting coronary heart disease (CAD) with quantitative coronary angiography (QCA) as the gold standard.Methods:A total of 95 consecutive patients (65 males, 30 females, age (56.2±8.5) years) who underwent ATP stress/rest MPI and coronary angiography (CAG) within one month in Fuwai Hospital, Chinese Academy of Medical Sciences from May 2018 to December 2018 were enrolled prospectively. The adverse reactions of ATP stress test were observed. Semi-quantitative analysis was performed on MPI results, and the summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were obtained. Quantitative analysis was performed on CAG images, and the degree of QCA coronary artery stenosis was analyzed. Using QCA as the gold standard, the diagnostic efficiency of ATP stress MPI was calculated. Pearson correlation analysis was performed to analyzed the relationship between SSS and the degree of QCA coronary artery stenosis.Results:In 95 cases, the incidence of adverse reactions in ATP stress test was 73.7%(70/95), which could be relieved automatically after drug withdrawal. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ATP stress MPI in diagnosing coronary artery stenosis ≥50% were 45.3%(24/53), 81.0%(34/42), 75.0%(24/32), 54.0%(34/63) and 61.1%(58/95) respectively, which were 15/16, 78.5%(62/79), 46.9%(15/32), 98.4%(62/63), and 81.1%(77/95) respectively in diagnosing coronary artery stenosis ≥70%. There was moderate correlation between SSS and the degree of QCA coronary artery stenosis ( r=0.418, P=0.017). Conclusion:ATP stress MPI has a clinical value in the diagnosis of myocardial ischemia in CAD.
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Objective:To investigate differences in cardiac function and perfusion parameters measured by IQ-SPECT and low energy high-resolution (LEHR)-SPECT, as well as effects of scattering correction (SC) and CT attenuation correction (AC) on myocardial perfusion imaging.Methods:From May 2020 to September 2020, 80 patients (58 males, 22 females, age (57±10) years) who underwent SPECT myocardial perfusion imaging were retrospectively enrolled in Fuwai Hospital. According to the standardized left ventricular end-diastolic diameter of body surface measured by two-dimensional echocardiography, patients were divided into 2 groups: A group ( n=34) with significantly enlarged left ventricle and B group ( n=46) with no significant enlargement of left ventricle. LEHR-SPECT and IQ-SPECT gated myocardial perfusion imaging were performed in all patients. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), summed rest score (SRS) and total perfusion defect (TPD) were measured. Parameters measured by two methods and differences before and after SC and AC were compared by using paired t test and Wilcoxon signed rank test. The correlation was analyzed by Pearson correlation or Spearman rank correlation analyses, and the consistency was analyzed by Bland-Altman analysis. Results:In A group, EDV, EF and SRS measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (257±137) vs (276±154) ml, EF: (21±11)% vs (26±13)%, SRS: 17(6, 25) vs 18(8, 28); t values: -2.63, -7.46, z=-2.14, all P<0.05); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.965, 0.969, 0.967, rs values: 0.920, 0.960, all P<0.001) and consistency. In B group, EDV and EF measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (96±40) vs (107±39) ml, EF: (46±15)% vs (54±16)%; t values: -6.23, -10.71, both P=0.001); SRS and TPD measured by IQ-SPECT after SC and AC were significantly lower than non-SC and non-AC (SRS: 2(1, 4) vs 5(3, 11), TPD: (3%(1%, 5%) vs 7%(3%, 12%); z values: -4.11, -4.16, both P<0.001); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.956, 0.978, 0.958, rs values: 0.926, 0.944, all P<0.001) and consistency. Conclusions:There are good correlation and consistency of left ventricular function and myocardial perfusion parameters acquired by IQ-SPECT and LEHR-SPECT. Moreover, IQ-SPECT is able to shorten acquisition time, resulting in great potential in clinical application.
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Objective:To study the feasibility of cardiac 99Tc m-methoxyisobutylisonitrile (MIBI)/ 123I-metaiodobenzylguanidine (MIBG) dual-isotope imaging with cadmium-zinc-telluride (CZT) SPECT. Methods:Using a heart phantom, 99Tc m-MIBI single-isotope imaging and 99Tc m-MIBI/ 123I-MIBG dual-isotope imaging were acquired separately. Model A, B, C represented normal heart, 99Tc m/ 123I matched myocardium, 99Tc m/ 123I mismatched myocardium, respectively. Nineteen patients (9 males, 10 females; age (56±16) years) from September 2018 to June 2020 at Fuwai Hospital were enrolled to participate 99Tc m-MIBI myocardial perfusion imaging and myocardial perfusion/cardiac sympathetic imaging with 99Tc m-MIBI/ 123I-MIBG dual-isotope. Perfusion percent (PP%) and summed rest score (SRS) for all myocardial segments were obtained using quantitative perfusion SPECT (QPS) software by analyzing myocardial perfusion images. Difference and relationship between PP% and SRS were analyzed (Pearson and Spearman correlation analyses). No physical correction was applied for both acquisitions. Analysis of variance for repeated measurement data and Mann-Whitney U test were used. Results:There was no significant difference in myocardial perfusion images between 99Tc m single-isotope and 99Tc m/ 123I dual-isotope imaging with the heart phantom. 123I did not significantly impact on 99Tc m images. For patients, PP% did not differ between 99Tc m single-isotope ((69.2±14.5)%) and 99Tc m/ 123I dual-isotope imaging ((69.5±16.2)%; F=0.005, P=0.946) and correlated well ( r=0.845, P<0.01). SRS for 99Tc m single-isotope was 2(1, 13) and 2(2, 12) for 99Tc m/ 123I dual-isotope imaging ( z=-0.774, P=0.439) and the correlation between the two acquisitions was excellent ( rs=0.975, P<0.01). Conclusions:Even without physical correction, cardiac images interpretation won′t be significantly influenced by the interference of 123I with relatively higher energy on 99Tc m images. Cardiac 99Tc m-MIBI/ 123I-MIBG dual-isotope imaging is feasible.
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Objective:To analyze the relationships between baseline percentage of pulmonary perfusion defect scores (PPDs%) and residual pulmonary hypertension after pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension (CTEPH) patients.Methods:A total of 37 CTEPH patients (21 males, 16 females, age (50±12) years) who had pre- and post-pulmonary endarterectomy ventilation/perfusion (V/Q) scans from January 2016 to January 2019 at Fuwai Hospital were retrospectively collected. Residual pulmonary hypertension was defined as post-surgery mean pulmonary artery pressure (mPAP) higher than 30 mmHg (1 mmHg=0.133 kPa). Semi-quantitative index PPDs% was calculated to represent the extent of impaired perfusion in the whole lung. Pre- and post-surgery pulmonary hemodynamic parameters including pulmonary arterial pressure and resistance and lung perfusion were compared. Factors that may be related residual pulmonary hypertension were analyzed using logistic regression analysis. Paired t test and independent-sample t test were also used. Results:Pulmonary endarterectomy significantly decreased mPAP ((50.22±11.72) vs (26.41±10.61) mmHg; t=12.599, P<0.001) and pulmonary vascular resistance((10.06±5.48) vs (2.89±1.58) Wood unit; t=8.086, P<0.001). The number of defected lung segments (13.79±2.11 vs 5.52±2.82; t=11.593, P<0.001) was significantly reduced. Patients who had residual pulmonary hypertension ( n=11) exhibited significantly higher PPDs% before the surgery compared to those who were without residual pulmonary hypertension ( n=26; (57.48±5.88)% vs (47.77±11.09)%; t=-3.458, P=0.002). Baseline PPDs% was an independent factor for predicting residual pulmonary hypertension after pulmonary endarterectomy (odds ratio ( OR)=1.106, 95% CI: 1.006-1.216, P=0.036). Conclusions:Pulmonary V/Q scan can assess the therapeutic effects of pulmonary endarterectomy. Extent of impaired lung perfusion assessed by V/Q scan is the influencing factor for post-surgery residual pulmonary hypertension.
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Objective@#To assess the superiority of 99Tcm-3SPboroxime (99Tcm-3SP for short) as a fast-myocardial perfusion imaging (MPI) tracer in normal and acute myocardial infarction (AMI) mini-swine.@*Methods@#99Tcm-3SP and 99Tcm-Teboroxime (99Tcm-TEBO for short) were prepared. Approximately 370 MBq 99Tcm-3SP or 99Tcm-TEBO was injected intravenously in 2 healthy mini-swine separately. Dynamic planar images were acquired immediately after injection and continued for 20 min using a standard SPECT camera. The radioactivity uptakes in the heart, liver, and lungs were measured, and heart/liver and heart/lung ratios over time were calculated. Dynamic SPECT studies were performed in 4 normal swine and 1 AMI-swine using cadmium zinc telluride-SPECT (CZT-SPECT). List mode acquisitions were immediately started and continued for 15 min after intravenous injection of approximately 370 MBq 99Tcm-TEBO and 99Tcm-3SP. The injection of two radiotracers in the same swine was completed within 2 d. The radioactivity uptakes in heart and liver were measured, and heart/liver ratio was calculated. Image quality was also evaluated. Paired t test was used to analyze the data.@*Results@#The radiochemical purity of 99Tcm-TEBO or 99Tcm-3SP were both above 95%. The initial heart uptake of 99Tcm-3SP was very close to that of 99Tcm-TEBO (planar image, 2 min postinjection: 309.32×103 vs 314.13×103 counts/MBq; SPECT image, 2 min postinjection (corrected): 7.96±0.87 vs 8.24±1.53, t=0.277, P>0.05), but the myocardial retention time was much longer than that of 99Tcm-TEBO (planar image, 20 min postinjection: 218.67×103 vs 143.19×103 counts/MBq; SPECT image, 15 min postinjection (corrected): 6.76±0.45 vs 5.06±0.33, t=-12.412, P=0.001). The uptake of liver and heart/liver ratio between 99Tcm-TEBO and 99Tcm-3SP were similar (t values: -1.332-1.101, all P>0.05 within 15 min). SPECT MPI images demonstrated uniform tracer distribution with clearly visualizable myocardial boundary in normal myocardium and intense perfusion defect in infarct myocardium. High quality SPECT images could be obtained in any of the 5 min imaging windows over the first 15 min after injection of 99Tcm-3SP in normal swine and AMI-swine.@*Conclusion@#99Tcm-3SP is a promising 99Tcm-labeled radiotracer for fast-MPI considering its high heart uptake, long myocardial retention time (20 min postinjection) and superior SPECT image quality.
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Objective To assess the superiority of 99Tcm-3SPboroxime (99Tcm-3SP for short) as a fast-myocardial perfusion imaging (MPI) tracer in normal and acute myocardial infarction (AMI) mini-swine.Methods 99Tcm-3SP and 99Tcm-Teboroxime (99Tcm-TEBO for short) were prepared.Approximately 370 MBq 99Tcm-3SP or 99Tcm-TEBO was injected intravenously in 2 healthy mini-swine separately.Dynamic planar images were acquired immediately after injection and continued for 20 min using a standard SPECT camera.The radioactivity uptakes in the heart,liver,and lungs were measured,and heart/liver and heart/lung ratios over time were calculated.Dynamic SPECT studies were performed in 4 normal swine and 1 AMI-swine using cadmium zinc telluride-SPECT (CZT-SPECT).List mode acquisitions were immediately started and continued for 15 min after intravenous injection of approximately 370 MBq 99Tcm-TEBO and 99Tcm-3SP.The injection of two radiotracers in the same swine was completed within 2 d.The radioactivity uptakes in heart and liver were measured,and heart/liver ratio was calculated.Image quality was also evaluated.Paired t test was used to analyze the data.Results The radiochemical purity of 99Tcm-TEBO or 99Tcm-3SP were both above 95％.The initial heart uptake of 99Tcm-3SP was very close to that of 99Tcm-TEBO (planar image,2 min postinjection:309.32× 103 vs 314.13 × 103 counts/MBq;SPECT image,2 min postinjection (corrected):7.96±0.87 vs 8.24± 1.53,t =0.277,P＞0.05),but the myocardial retention time was much longer than that of 99Tcm-TEBO (planar image,20 min postinjection:218.67× 103 vs 143.19× 103 counts/MBq;SPECT image,15 min postinjection (corrected):6.76±0.45 vs 5.06±0.33,t =-12.412,P =0.001).The uptake of liver and heart/liver ratio between 99Tcm-TEBO and 99Tcm-3SP were similar (t values:-1.332-1.101,all P＞0.05 within 15 min).SPECT MPI images demonstrated uniform tracer distribution with clearly visualizable myocardial boundary in normal myocardium and intense perfusion defect in infarct myocardium.High quality SPECT images could be obtained in any of the 5 min imaging windows over the first 15 min after injection of 99Tcm-3SP in normal swine and AMI-swine.Conclusion 99Tcm-3SP is a promising 99 Tcm-labeled radiotracer for fast-MPI considering its high heart uptake,long myocardial retention time (20 min postinjection) and superior SPECT image quality.
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Objective@#To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections.@*Methods@#A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise reduction (NR), NR+ scatter correction (SC), NR+ SC+ resolution recovery (RR)), NR+ SC+ RR+ attenuation correction (AC; total corrections, TC). Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality (R2) and fraction blood volume (FBV) to assess the quality of modeling. Rest MBF (RMBF), stress MBF (SMBF) and myocardial flow reserve (MFR) quantified from no correction (NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear regression analysis were used to analyze the data.@*Results@#Compared to TC, NC showed the lowest R2 (rest: 0.69, stress: 0.78; z values: 4.78 and 4.78, both P<0.01) and highest FBV (rest: 0.37, stress: 0.40; z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR (z values: 1.27 and -3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values: from -4.55 to 1.27, all P<0.01). NR and NR+ SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+ SC, NR+ SC+ RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1.129-1.308, and Bland-Altman plots demonstrated positive biases (0.60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70, -0.11, -0.05, 0.01).@*Conclusion@#Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pinhole CZR-SPECT.
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Objective To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections. Methods A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise re-duction ( NR) , NR+scatter correction ( SC) , NR+SC+resolution recovery ( RR) ) , NR+SC+RR+attenua-tion correction ( AC;total corrections, TC) . Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality ( R2 ) and fraction blood volume ( FBV) to assess the quality of modeling. Rest MBF ( RMBF) , stress MBF ( SMBF) and myocardial flow reserve ( MFR) quantified from no correc-tion ( NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear re-gression analysis were used to analyze the data. Results Compared to TC, NC showed the lowest R2( rest:0.69, stress:0.78;z values:4.78 and 4.78, both P<0.01) and highest FBV ( rest:0.37, stress:0.40;z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR ( z values:1.27 and-3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values:from -4.55 to 1.27, all P<0.01). NR and NR+SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+SC, NR+SC+RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1. 129-1. 308, and Bland-Altman plots demonstrated positive biases (0. 60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70,-0.11,-0.05, 0.01). Conclusion Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pin-hole CZR-SPECT.
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Objective To evaluate the effect of anticoagulant therapy by pulmonary ventilation/perfusion (V/Q) imaging in chronic thromboembolic pulmonary hypertension (CTEPH) patients.Methods Thirtysix CTEPH patients (16 males,20 females,average age:(53.8±13.8) years) diagnosed by pulmonary angiography from January 2013 to December 2015 were included in this retrospective study.All patients received anticoagulant therapy for more than 6 months.They underwent pulmonary V/Q imaging before and 6 months after anticoagulant therapy.The numbers of pulmonary segments with perfusion defect,percentage of perfusion defect score (PPDs) and pulmonary arterial systolic pressure (PASP) before and after anticoagulant therapy were measured by echocardiography.Pair t test was used for data analysis.Results Before anticoagulant therapy,there were 319 pulmonary segments with perfusion defect in 36 CTEPH patients,8.9± 3.4 on average,and reduced to 8.4+3.6 after anticoagulant therapy (t =3.101,P＜0.01).The PPDs before and after anticoagulant therapy were (43.3±19.7)％ and (40.8±+20.5)％ (t=2.364,P＜0.05).In the subgroup of 9 patients with improved pulmonary perfusion,the PASP significantly decreased from (68.7±27.3)to (56.1 +±34.8) mmHg (1 mm Hg =0.133 kPa;t =2.465,P＜ 0.05) after anticoagulant therapy.In contrast,in the subgroup of 27 patients with no improved pulmonary perfusion,the PASP before and after anticoagulant therapy were (71.3±26.9) and (76.7±35.0) mmHg respectively (t=-1.511,P＞0.05).Conclusion Pulmonary V/Q imaging is a reliable method for evaluating the changes of pulmonary perfusion before and after anticoagulant therapy,and it is valuable for assessing the effect of anticoagulant therapy in CTEPH patients.
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Objective To prospectively compare cadmium-zinc-telluride (CZT) SPECT gated myocardial perfusion imaging (GMPI),conventional SPECT MPI and cardiac MRI for the assessment of left ventricular volume and ejection fraction in patients with heart failure.Methods From July 2016 to October 2016,a total of 35 patients (27 males,8 females,average age:(52.7±14.9) years) with heart failure were consecutively included.All patients underwent CZT SPECT GMPI,conventional SPECT GMPI and cardiac MRI within 7 d.LVEDV,LVESV and LVEF of three imaging modalities were calculated.One-way analysis of variance,Pearson correlation analysis and Bland-Altman analysis were used.Results CZT SPECT showed excellent correlation with conventional SPECT for LVEDV,LVESV and LVEF (r values:0.983,0.986 and 0.910,respectively;all P＜0.001).Bland-Altman analysis revealed good agreement between CZT SPECT and conventional SPECT for LVEDV,LVESV and LVEF.The correlation between CZT SPECT and cardiac MRI for LVEDV,LVESV and LVEF were all significant (r values:0.864,0.896 and 0.836,respectively;all P＜0.001).Compared with cardiac MRI,CZT SPECT showed systemic underestimation of LVEDV and LVESV and good agreement of LVEF by Bland-Altman analysis.Conclusions CZT SPECT has high clinical value for patients with heart failure.Despite underestimating LVEDV and LVESV,it correlated well with cardiac MRI.It also has a good agreement with conventional SPECT on left ventricular volume and LVEF.
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Objective: To dynamically evaluate left ventricular perfusion, global and local functional changes during left ventricular aneurysm (LVA) formation and to explore the relationship between the size of LVA and LVEF, LVESV, LVEDV by gated99mTc-MIBI SPECT (GSPECT) and gated18F-FDG PET metabolic (GPET) imaging in experimental pigs. Methods: LVA model was established by occlusion of left circumlfex artery (LCX) and placing an Ameroid constrictor at the proximal end of left anterior descending artery (LAD) in a total of 16 Chinese mini-pigs. At the 1st, 4th and 8th weeks of surgery, the changes of total perfusion defect (TPD), LVA formation and LVEF, LVESV, LVEDV were dynamically evaluated by GSPECT and GPET; the relationships between the size of LVA and LVEF, LVESV, LVEDV were analyzed respectively.Results: There were 5 pigs died in surgery and 2 died at the 1st week of modeling. According to golden (pathological) standard, 9 animals successfully ifnished the dynamic imaging study. At the 1st week of (basic) modeling, 4 animals formed large LVA, 2 formed small LVA at the apex and 3 without LVA formation. At the 4th and 8th weeks of modeling, dynamic imaging presented that the animals with large LVA had gradually increased range and degree of perfusion defect, LVEDV, LVESV, while gradually decreased LVEF; the above indexes were relatively stable in animals with small or none LVA. In addition, the size of LVA was related to LVEF (r=-7.26), LVEDV (r=0.855) and LVESV (r=0.825), allP<0.05. Conclusion: In experimental pigs, at the beginning of LVA formation, large range and severe perfusion defect may cause large aneurysm, the LV functional damage and remodeling may gradually increase and the prognosis is poor; in contrast, the animals with small or none LVA have better prognosis and usually without ventricular remodeling; which implies that in acute phase of LVA formation, the size of aneurysm may predict the trend of global LV systolic function and remodeling at the early stage.
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Objective: To assess the impact of viable myocardium in left ventricular aneurysm (LVA) and ventricular arrhythmia on prognosis of LVA patients. Methods: A total of one hundred and sixty LVA patients who received99Tcm-MIBI SPECT and18F-FDG PET were enrolled, including 139 male and 21 female with the mean age of (58 ± 10) years.There were 42 (26.3%) patients combining ventricular arrhythmia. LVEDV, LVESV and LVEF were detected. Semi-quantitative analysis of myocardium perfusion imaging was conducted, viable myocardium in aneurysm was deifned as the perfusion-metabolism mismatch score (MMS) ≥ 2.0. According to myocardium viability, the patients were divided into 2 groups: No viability group,n=97 and With viability group,n=63;based on ventricular arrhythmia, the patients were divided into another 4 groups: Group①, viability-, ventricular arrhythmia-, n=68, Group②, viability-, ventricular arrhythmias+,n=29, Group③, viability+, ventricular arrhythmias-,n=50 and Group④, viability+,ventricular arrhythmias+,n=13. The average follow-up time was (50 ± 7) months, the end point was cardiac death. The survival curve was obtained by Kaplan-Meier method and survival rates were compared by Log-rank analysis. Results: The mean LVEF in 160 patients was (34 ± 11) %, cardiac death occurred in 19 (11.9%) patients. Long-term survival rates in Groups①,② and③ were 94.1%, 89.7% and 86.0%, respectively,P>0.05; while in Group④, the survival rate was 61.5%, which was lower than the other 3 groups,P=0.004. Multivariate Cox regression analysis showed that female (HR=5.101, 95% CI 1.853-14.044, P=0.002), GPET-ESV (HR=1.009, 95% CI 1.002-1.015,P=0.013), interaction between MMS and ventricular arrhythmia (HR=1.368, 95%CI 1.113-1.681,P=0.003) were independent risk factors for cardiac death;while surgical treatment (HR=0.199, 95% CI 0.054-0.742,P=0.016) could decrease the risk of cardiac death. Conclusion: Patients with viable aneurysm and ventricular arrhythmia had poor long-term prognosis; while early and active treatment is needed for them (surgery with anti-arrhythmic therapy).