Abstract 13193: Prevalence of Late Gadolinium Enhancement Following Pediatric Heart Transplantation Increases With Time Since Transplantation

Abstract

Introduction: Chronic graft failure in pediatric heart transplant recipients (PHT) is associated with myocardial fibrosis on explanted specimens. Cardiac magnetic resonance imaging (CMR) is a validated, non-invasive method to detect myocardial fibrosis via the presence of late-gadolinium enhancement (LGE). In adult heart transplant recipients, LGE is associated with increased risk of hospitalization and death. We describe LGE on CMR among PHT and its associations with clinical and graft characteristics. Methods: We performed a retrospective chart review of all PHT who underwent CMR over a 6-year period at a single center (81 CMR studies, 59 unique patients). Two independent reviewers assessed the presence and distribution of LGE using the AHA 17-segment model. Clinical history and CMR-derived volumetry/ejection fraction were obtained; differences between LGE+ and LGE- PHT were evaluated. Results: Mean age at CMR was 14.8±4.6y; mean time since transplant was 7.3±5.0y. CMR indication was routine surveillance (without active rejection or history of cardiac allograft vasculopathy) in 63% (51/81) of studies. LGE was present in 36% (29/81). LGE patterns included: posterior hinge-point 27% (22/81), lateral wall 15% (12/81), and extensive, involving >4 AHA segments, 7% (6/81) (Figure). Reviewing initial CMR per PHT (n=59), LGE+ patients were older (17 vs. 13y; p=0.001), with greater time since transplant (8.3 vs. 5.7y; p= 0.041). They demonstrated increased indexed LV end-systolic volume (35 vs. 29 ml/m2; p=0.011) and decreased LV ejection fraction (56.2 vs 60.6%; p=0.015). There were no significant differences in history of moderate/severe rejection or cardiac allograft vasculopathy. Conclusions: LV LGE was seen in about a third of PHT patients, more commonly in older patients with longer time since transplantation. Grafts with LGE show remodeling with lower LV ejection fraction. CMR-derived LGE may improve surveillance of chronic graft failure in PHT.