Abstract
1186
Objectives: Left ventricular systolic dyssynchrony(LVSD) is an important factor leading to cardiac dysfunction and poor prognosis in patients with coronary heart disease(CAD). Phase analysis of gated single photon emission computed tomography (SPECT) image data is increasingly appreciated as a tool for quantifying LVSD. Additionly,the extent of viable myocardium(Mismatch)and scar (Match) can accurately be assessed by 99mTc-SPECT myocardial perfusion imaging (MPI)combing with 18F-FDG positron emission tomography (PET) myocardial metabolic imaging . Previous study demonstrated that dyssynchrony parameter values may be spuriously increased by scar. However, the relationship between viable myocardium and LVSD has not been adequately evaluated. The purpose of this study is to explore the relationship between viable myocardium and LVSD in patients with CAD.
Methods: Ninety-one CAD patients ready for revascularization and seventy-four healthy volunteers (control group) underwent resting GMPI were included in this study. In addition, the CAD group underwent 18F-FDG PET myocardial metabolic imaging the next day.The LVSD parameters including phase histogram bandwidth (BW) and phase standard deviation (SD) were obtained by Cedars-Sinai quantitative gated SPECT (QGS) phase analysis technique, and LV cardiac function was also measured[LV end-diastolic volume(LVEDV) and end-systolic volume (LVESV),left ventricular ejection fraction(LVEF)]. The extent of myocardial perfusion defect (Extent),Mismatch,scar were analyzed by the Quantitative (QPS) software combining 18F-FDG PET and SPECT MPI imaging . The value of BW and SD were compared between CAD and the control groups. LVSD was defined when the BW exceeded the abnormality threshold derived from a normal control group (threshold =mean±2s for normal BW), dividing the CAD patients into into two groups: left ventricular systolic synchrony group and dyssynchrony group. The clinical data ,LV cardiac function parameters,Mismatch and scar were compared between the two groups and further to identify independent predictors for LVSD.
Results: (1) The BW [(69.3±42.2)°vs.(37.2±11.7)°] and SD [(20.7±12.3)°vs.(11.8±5.4)°] were significantly higher and the LVEF [(47.9±15.8)%vs.(68.9±9.5)%]was significantly lower in CAD group than in the normal control group (all p<0.001). (2) Dyssynchrony (BW > 60.6°) prevalence was 40.6%,(37/91)in CAD patients. Compared with the synchrony group, LVEF [(35.5±14.1)%vs.(56.6±10.2)%,P<0.001]was significantly lower, while the hypertension prevalence ,NYHA classification ,history of myocardial infarction, LVEDV ,LVESV , Mismatch and scar were significantly higher in dyssynchrony group (all P <0.001). (3) Multivariate logistic regression analysis revealed that the Mismatch was an independent risk factor for LVSD in CAD patients (OR=1.097 ,95% CI:0.713-0.905,P=0.019) . (4) The cut-off value of Mismatch is 6.5%,(percentage LV aera) had a 78.9% sensitivity and 77.8% specificity (AUC 0.809) for predicting LVSD.
Conclusion: The extent of viable myocardium is an independent risk factor for LVSD in CAD patients.The viable myocardium (蠅 6.5% LV area ) can predict LVSD in patients with CAD. Research Support: (1)The Project supported by National Natural Science Foundation of China (81471690); (2)The Key Development Foundation of Jiangsu Province (BE2015635); (3)The Major Project of Changzhou Municipal Bureau of Health Science and technology(ZD201409)