Abstract 13094: Association Between Myocardial Strain Using 2d and 3d Speckle-tracking Echocardiography and Diffuse Myocardial Fibrosis in Heart Transplant Recipients

Abstract

Background: Myocardial fibrosis (MF) is a well-described histopathologic featurein patients after heart transplant (HT). The two-dimensional speckle-tracking echocardiography (2D-STE) derived strain has been reported as a noninvasive tool to predict myocardial fibrosis (MF). Nevertheless, the relation between three-dimensional (3D)-myocardial strain and MF, and which directions of strain components correlated best with MF in HT recipients have not been reported. Objective: The study aimed to 1) explore whether diffuse left ventricular (LV) MF defined by cardiovascular magnetic resonance (CMR)- extracellular volume fraction (ECV) is expanded; 2) evaluate the association between LV MF and LV strain measured by 2D- and 3D-STE, and investigate which strain parameter is the more robust predictor of LV MF in patients after HT. Methods: A total of 60 subjects (40 patients after HT and 20 healthy controls) were prospectively enrolled. All subjects underwent the 2D, 3D echocardiography and CMR examination. The LV ejection fraction (EF) was measured by 3D-STE. The LV- global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were measured by 2D- and 3D-STE. And LV diffuse MF was defined by ECV using the modified Look-Locker inversion recovery (MOLLI) sequence. Results: The HT recipients had higher native T1 and ECV than healthy controls (1042.8±35.3ms vs 1006.3±19.6ms, p<0.001; 26.8±3.4% vs 24.6±1.3%, p=0.02). And compared with healthy controls, the 3D-GLS, 3D-GCS, 3D-GRS and 2D-GLS were all lower (p<.005) in the HT recipients. But 3D-LVEF was similar in HT patients and healthy controls. And in the HT group, the increased ECV only correlated with 2D-GLS (r=0.57, p=0.001) and 3D-GLS (r=0.51, p < 0.001), not correlated with 2D- and 3D-GCS, GRS. The separate stepwise multivariate analysis showed that both 2D-GLS (β=0.74, p=0.001) and 3D-GLS (β=0.69, p < 0.001) were independently associated with LVECV. Conclusions: Patients after HT have higher LV MF and reduced LV strain compared with control subjects. Moreover, both 2D- and 3D-GLS are the independent predictor of diffuse LV MF. Therefore, the measurement 2D- and 3D-GLS may be provide a noninvasive assessment of LV MF in the transplanted hearts.