Role of Echocardiographic Deformation Indices in Predicting Mild Forms of Rejection in Heart Transplantation Recipients

Abstract

Background: Endomyocardial biopsy (EMB) is currently the method of choice for the definite diagnosis of acute allograft heart rejection after transplantation. But, it is somewhat invasive and expensive and, on occasion, gives rise to serious complications. To find a non-invasive method for the identification of acute allograft rejection, we compared the results between EMB according to the criteria of the international society of heart and lung transplantation (ISHLT) and myocardial deformation indices (color-coded tissue Doppler imaging (TDI)-derived strain and strain rate (SR) imaging). Methods: In 31 heart transplantation recipients followed up in our transplant clinic, EMB was achieved with a time lapse of 3 to 12 months after heart transplantation and color-coded TDI was performed during a 24-hour period after the biopsy procedure. The peak values of systolic strain and SR were determined in all 12 segments of the left ventricle (LV) except the apical segments. Results: All the 31 heart transplantation patients were included in the study. According to the ISHLT’s criteria, 13 EMB samples revealed grade IR rejection and only 1 biopsy sample revealed grade IIR. ROC curve analysis was used for all the 12 LV segments. There were no meaningful correlations between the TDI-derived mean strain and SR values and the EMB results. The only meaningful correlation was between the SR of the infero-basal segment and the pathology result. The area under the curve was 0.73 (P = 0.024). Conclusions: Our results did not reveal a meaningful correlation between TDI-derived strain and SR and EMB results, but colorcoded TDI-derived strain and SR imaging might have a complementary role for the identification of higher grades of acute allograft rejection in heart transplantation recipients. In our study, 1 EMB sample revealed grade IIR and no biopsy sample revealed grade IIIR; thus, a better assessment of the role of strain and SR imaging in predicting rejection requires further research with higher numbers of patients including higher grades of acute allograft rejection and novel techniques of stain rate imaging like speckle-tracking 2D strain imaging.