| Purpose:(1)To evaluate the prognostic value of left ventricular(LV)remodeling parameters in patients with LV aneurysm by gated positron emission tomography(PET)and cardiac magnetic resonance(CMR),combined with number of diseased vessels,and to analyze the independent predictor risk factor for long-term cardiac death,and try to establish a Cox model for predicting cardiac death;(2)to evaluate the impact of myocardial viability and LV remodeling on the long-term cardiac survival in patients with LV aneurysm.Methods:164 consecutive patients(144 men;mean age,58± 9 y,mean LVEF:32%± 9%by PET)underwent gated 99mTc-MIBI SPECT myocardial perfusion imaging,gated18F-FDG PET metabolic imaging,and CMR within 2 weeks were retrospectively enrolled,with a mean follow-up of 3.9 ± 1.4 ys.End diastolic volume(EDV)and end systolic volume(ESV)measured by gated-PET,gated-SPECT and CMR and then corrected for body surface area(BSA),thus EDV index(EDVI)and ESV index(ESVI)were obtained.Myocardial perfusion imaging and metabolic imaging were semi-quantitatively analyzed by 17-segment model and 5-point score system.Summed rest score(SRS)and summed FDG defect score(SFS)were obtained,then,myocardial perfusion-metabolism mismatch score(MMS)was calculated by SRS-SFS.It indicated the amount of myocardial viability.Cardiac death was served as the only end event.Continuous data were expressed as mean ± standard deviation.Mean values of continuous variables were compared by paired Student' s t test or by one-way ANOVA analysis.Categorical variables were expressed as percentages and the Chi square test was used.The Cox proportional hazards regression analysis model was used to identify independent variables for cardiac death by univariate and multivariate analysis.Only variables with a statistically significant(p<0.1)association with the correlation by univariate analysis were included in the multivariate analysis,which was performed by a forward stepwise method.All statistical analyses were performed using SPSS 20.0 Kaplan Meier method was used to obtain the cardiac survival curve,and statistics difference was analyzed by the Log-rank method.Patients were stratified into low risk group and high risk group,according to the myocardial viability(LV-MMS ? 6.0,8.8%of LV),revascularization,three vessel disease and severe left ventricular remodeling(gated PET-ESVI>120 mL/m2).Patients who were treated by revascularization and those without any risk factors were considered as at low risk for cardiac death.Patients with more than or equal to 1 risk factor were considered as at high risk for cardiac death.Results:The median follow-up period was 4.0 years(range:0.1-6.6 years),and there were 25 patients(15.2%)suffered from cardiac death.Multivariate Cox proportional regression analysis showed that independent risk factors for prediction cardiac death include:revascularization(HR 0.210,95%CI:0.073-0.607,p=.004),SFS(HR 1.092,95%CI:1.036-1.151,p=.001),aneurysmal MMS(HR 1.460,95%CI:1.193-1.787,p<.0001),the number of diseased vessels(HR 2.262,95%CI:1.275-4.013,p =.005)and the mount of myocardial infarction(SFS)(HR 3.000,95%CI:1.080-8.334,p =.035).Introduced interaction Cox multi-factor analysis revealed that PET-ESVI was interacted with aneurysmal MMS(HR 1.007,95%CI:1.004-1.011,p<.0001),and was a positive independent risk factor of cardiac death,and the same as,LV-MMS and revascularization had interaction with each other(HR 0.737,95%CI:0.577-0.942,p =.015)and was a negative independent predict risk factor for cardiac death.Diseased vessels(HR 1.784,95%CI:1.017-3.132,p =.044)and SFS(the extent and severity of myocardial infarction)(HR 1.078,95%CI:1.029-1.129,p =.001)after the introduction of interaction,was still an independent risk factor for cardiac death.Kaplan-Meier analysis showed that revascularization therapy alone could improve cardiac survival in comparison with medical therapy(Log Rank x2 = 10.089,p =.001).Patients were divided into 2 subgroups by LV-MMS 6(8.8%/LV),then,revascularization could significantly improve the cardiac survival in patients with LV-MMS ?6 in comparison with medical therapy(Log Rank x2 = 10.258,p =.001),while no statistic difference was observed between patients treated by medical therapy and revascularization in patients with LV-MMS<6(Log Rank x2= 1.980,p =.159),Combined with clinical information,the basic model was established,which was consisted by three parameters:revascularization therapy,myocardial viability(LV-MMS ? 6)and three vessel disease.Patients who were treated by revascularization were at low risk group for cardiac death,and patients without myocardium viability and without 3-vessel disease were at low-risk for cardiac death,the other patients were considered as at high-risk group.Further,ESVI>120 mL/m2(severe left ventricle remodeling)and/or SFS>30(44%/LV)were introduced into the basic model to predict cardiac death.Comparing the area under the ROC curve(AUC)of the different prediction model,the larger of AUC value,it indicates the higher predicted value for cardiac death.AUC of LV-MMS,3-vessel disease and revascularization was 0.708(95%CI:0.588-0.829.AUC of LV-MMS,3-vessel disease,revascularization and SFS>30 was 0.704(95%CI:0.590-0.818).AUC of LV-MMS,3-vessel disease,revascularization,and severe ventricular remodeling was 0.748(95%CI:0.636-0.860).AUC of LV-MMS,3-vessel disease,revascularization,severe ventricular remodeling and SFS>30 was 0.708(95%CI:0.594-0.822).The results suggest that severe left ventricular remodeling could increase predict value of the basic model the predictive value of cardiac death,and myocardial infarction could not.Conclusion:Revascularization could improve the long-term cardiac survival of patients with LV aneurysm and aneurysmal viability,on the other hand,if patients without myocardium viability,patients could be treated by medical therapy.Combination of myocardial viability,three vessel disease,severe left ventricular remodeling,these three positive independent predictor factors with revascularization,a negative independent predictor,to establish a Cox-risk model and could predict the risk of cardiac death in patients with ischemic heart disease with LV aneurysm.The LV remodeling parameter could improve the predict value of the basic model,while the extent of myocardial infarction could not.Thus in patients with LV aneurysm,combination of different information,including myocardial viability,3-vessel disease,the extent of LV remodeling could identify the most risk patients for cardiac death,while revascularization could significantly improve the long-term cardiac survival in these patients.Purpose:(1)To evaluate the prognostic value of left ventricular(LV)remodeling parameters in patients with LV aneurysm by gated single photon emission computed tomography(SPECT),gated positron emission tomography(PET)and cardiac magnetic resonance(CMR);(2)to evaluate the impact of myocardial viability and LV remodeling on the long-term cardiac survival in patients with LV aneurysm.Methods:126 consecutive patients(111 men and 15 women;mean age,56.9± 9.6 y,mean LVEF:32%± 10%by CMR)underwent gated 99mTc-MIBI SPECT myocardial perfusion imaging,gated 18F-FDG PET metabolic imaging,and CMR within two weeks,with a mean follow-up of 3.9 ± 1.5 y.End diastolic volume(EDV)and end systolic volume(ESV)measured by gated-PET,gated-SPECT and CMR and corrected for body surface area(BSA),thus EDV index(EDVI)and ESV index(ESVI)were obtained.Patients were divided into three groups by aneurysmal viability[MMS of aneurysm ? 2.0]and LV remodeling(ESVI by gated-PET>60 mL/m2).Group 1(Viability-,LV remodeling-);Group 2(Viability-,LV remodeling +)and Group 3(Viability+,LV remodeling-/+).Results:ESVI by gated-PET,MMS of aneurysm and summed rest perfusion score of aneurysm by multivariate regression analysis;as well as ESVI by gated-PET(HR 1.024,95%CI:1.011?1.037,p=.0004),MMS of aneurysm(HR 1.284,95%CI:1.051?1.577,p=.015)by interaction analysis were approved being independent predictors for cardiac death(p<.05).The long-term cardiac survival was significantly improved by revascularization in comparison with medical therapy in Group 3(p<.01),but did not significantly differ between Groups 1 and 2.Conclusions:ESVI by gated-PET showed a significant positive predictive value for cardiac death.Patients with viable myocardial aneurysm were most likely at increased risk for cardiac death and coronary revascularization was significantly associated with improved long-term cardiac survival.In contrast,the long-term cardiac survival of patients without LV remodeling and without aneurysmal viability was promising and,thus,could be treated by medical therapy. |
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