Diagnostic value of myocardial strain using two-dimensional speckle-tracking echocardiography in acute cardiac allograft rejection: A systematic review and meta-analysis

Background Two-dimensional speckle-tracking echocardiography (2D STE) has been demonstrated to have certain diagnostic utility in heart transplantation (HTX) patients with acute cardiac allograft rejection (ACAR). The aim of the systematic review and meta-analysis was to evaluate the diagnostic value of common strain parameters for ACAR in HTX patients. Methods After conducting a database search, we selected studies evaluating left ventricular global longitudinal strain (GLS), circumferential strain (CS), radial strain (RS), and free wall right ventricular longitudinal strain (RV FW) in rejection group vs rejection-free group. Results After reviewing 886 publications, seven studies were finally included in the meta-analysis, representing the data of 1173 pairs of endomyocardial biopsy and echocardiographic examination. Heart transplantation patients with rejection had significantly lower GLS than rejection-free subjects (weighted mean difference -2.32 (95% CI, -3.41 to -1.23; P < .001). Heart transplantation patients with rejection had significantly lower CS than rejection-free subjects (weighted mean difference -2.49 (95% CI, -4.05 to -0.91; P = .0019). In addition, HTX patients with rejection also had significantly lower RV FW (weighted mean difference -4.90 (95% CI, -6.15 to -3.65; P < .001). Conclusions The meta-analysis and systematic review demonstrate that myocardial strain parameters derived from 2D STE may be useful in detecting ACAR in HTX patients. The present results provide encouraging evidence to consider the routine use of GLS, CS, and RV FW as markers of graft function involvement during ACAR.