Right Ventricular Dysfunction as an Echocardiographic Measure of Acute Rejection Following Heart Transplantation in Children

Noninvasive biomarkers of acute allograft rejection (AAR) following orthotopic heart transplantation (OHT) are needed. The aim of this study was to investigate the accuracy of echocardiographic (ECHO) right ventricular (RV) global functional and resistance indices in the detection of AAR. This retrospective chart review included children with biopsy-proven AAR (grade >= 2R cellular or CD4 + antibody-mediated rejection) following OHT and an ECHO within 12 h of the biopsy. ECHO measures: (a) ratio of systolic to diastolic duration (S/D), (b) RV myocardial performance index (MPI) and (c) tricuspid regurgitant gradient to RV outflow tract velocity time integral ratio (TRG/VTI), were derived at baseline, during AAR and at two follow-ups. Sixteen patients [56% male, mean (SD) age at OHT 3.5 (4.3) years] had 16 AAR episodes. S/D (1.15 vs. 1.60, p < 0.01), RV MPI (0.19 vs. 0.39, p < 0.01) and TRG/VTI (1.05 vs. 1.7, p = 0.01) deteriorated during AAR and, except for diastolic duration, improved significantly at first follow-up. The negative predictive values for S/D, RV MPI and TRG/VTI at cutoffs of 1.3, 0.31 and 1.3 were 97, 97 and 87%, respectively. RV S/D, MPI and TRG/VTI deteriorated during AAR. Their excellent negative predictive values suggest that their incorporation in surveillance may obviate the need for routine biopsies.