Biventricular Myocardial Strain Correlates With Myocardial Fibrosis In Patients With End-stage Dilated Cardiomyopathy:A Study Using Three-dimensional Speckle Tracking Echocardiography

Purpose To evaluate the accuracy of biventricular strain by three-dimensional speckle tracking echocardiography(3D-STE)in predicting myocardial fibrosis in patients with end-stage dilated cardiomyopathy(DCM)undergoing heart transplantation.Methods We enrolled 35 patients with end-stage DCM undergoing echocardiography before heart transplantation.Left ventricular(LV)global longitudinal strain(GLS),global circumferential strain(GCS),global radial strain(GRS)and right ventricular(RV)free wall longitudinal strain(LS)were measured by 3D-STE.LV and RV ejection fraction(EF)were obtained from cardiac magnetic resonance(CMR).LV and RV tissue samples were obtained from all patients who underwent heart transplantation and 5 donors without cardiac diseases,All myocardial tissue samples were performed by Masson staining.Image-pro Plus 6.0 software was used to semi-automatic quantify the ratio of the fibrotic area to the total sample area(Collagen volume fraction,CVF%)to determine the extent of myocardial fibrosis.Results(1)Compared with the control group,the degree of myocardial fibrosis in DCM was significantly increased in both LV and RV of the DCM group(p <0.05).There was no significant difference between LV CVF and RV CVF in the control group(p=0.437).LV CVF was higher than RV CVF in DCM group,the difference was statistically significant(p=0.037).(2)In DCM group,LV CVF strongly correlated with GLS(r = 0.74,p <0.001),modestly with GRS(r =-0.66,p<0.001),weakly with GCS(r = 0.44,p<0.01),but not with CMR-derived LVEF;(3)RV CVF was strongly associated with RV free wall LS(r =0.71;p< 0.001),modestly with RV FAC(r=-0.57? p<0.01),weakly with TAPSE and RV length(r =-0.377;p=0.026;r =-0.360;p =0.034),but not with CMR-derived RVEF.(4)Stepwise multivariate analysis showed that LV GLS(?=0.798,p< 0.001)and RV free wall LS(?= 0.752,p< 0.0001)were independent predictors of LV and RV myocardial fibrosis respectively.Conclusion: Both left and right ventricular myocardial fibrosis increased significantly in patients with end-stage DCM.LV GLS and RV free wall LS is the most accurate LV and RV global function measure that correlates with myocardial fibrosis in patients with end-stage DCM.