Speckle-Tracking Echocardiography for Monitoring Acute Rejection in Transplanted Heart

Background. The diagnosis of acute cellular rejection (ACR) is a major objective in the management of heart transplant recipients. The aim of this study was to assess the utility of speckle-tracking derived parameters in identifying patients at risk of graft rejection. Methods. A prospective, single-center study was carried out involving 45 consecutive heart transplant patients who underwent a total of 220 routine endomyocardial biopsies (EMBs) with correlative echocardiographic examination. Results. No significant ACR (grade 0-1R) was seen in 190 biopsies (81.2% of the ACR-free group), and moderate ACR requiring specific treatment (grade 2R) was detected in 30 biopsies (13.6% of the ACR group). Grade 3R was not observed. All longitudinal left ventricular (LV) and right ventricular (RV) strain parameters were greater in the ACR-free group than in patients with ACR, while no differences were observed between radial and circumferential strain parameters. In our analysis, we selected RV free wall longitudinal strain (RV FW) <= 16.8% and 4-chamber longitudinal strain (4CH LS) <= 13.8%, which related to the presence of ACR requiring treatment. We assigned 1 point for each parameter (minimum 0, maximum 2 points) and derived a new echocardiographic index, the Strain Rejection Score (SRS). Our proposed approach a combination of the 2 abovementioned indices for screening patients at risk of ACR >= 2R, when expressed by a score 2 points, showed good specificity, strong negative predictive value, and the highest area under the curve. Conclusions. Our study demonstrated that combination of 4CH LS and RV FW as a new echocardiographic index, the Strain Rejection Score, can be useful as a noninvasive assessment of ACR during the first year of follow-up after heart transplant.