Abstract 19397: Changing Risk of Rejection After Pediatric Heart Transplant Over Time
Introduction: Due to limited and conflicting data regarding the risk of late rejection in pediatric heart recipients in the contemporary era, the practice of long-term surveillance endomyocardial biopsy (EMB) remains controversial.
Hypothesis: We assessed the hypothesis that rejection risk in pediatric patients declines steadily over time after transplant.
Methods: We retrospectively reviewed all EMBs performed at a single institution from 5/1995-9/2015. We defined significant cellular rejection as ≥2R (2004 ISHLT Grade) or ≥3A (1990 ISHLT Grade). We fit a logistic regression model with robust standard errors to characterize rejection risk over six time intervals (categorized as 0-2 years in 6-month intervals, 2-5 years, and 5+ years), accounting for demographics, CHD diagnosis, and number of prior positive EMB. We additionally estimated the unadjusted association of prior biopsies and rejection risk.
Results: A total of 5131 EMB were performed on 220 patients with a median age at transplant of 10.2 (IQR 2.2, 14.6) years. Patients underwent a median of 22 EMB (IQR 13, 31). Ninety-five (43%) patients experienced at least one rejection episode post-transplant, and among these patients, the median time to first rejection was 14 (IQR 2, 28) months. Based on our model, 75% of the EMB had a probability of rejection below 0.04. Compared to the 1.5-2yr interval, rejection risk was significantly lower in both the 2-5 and 5+ year intervals (Table). Each additional prior positive biopsy was associated with a 1.6x increase in odds of rejection (CI 1.5-1.8, P<0.001).
Conclusions: In conclusion, the risk of identifying rejection in biopsies peaks within the first two years post-transplant and declines considerably thereafter. Previous episodes of rejection are associated with significantly increased risk of future rejection. These findings may help to focus the practice of long-term surveillance biopsy on those patients at greatest risk of rejection.
Author Disclosures: D.M. Peng: None. V. Ding: None. T. Khalapyan: None. P.D. Carter: None. J.C. Dykes: None. D.N. Rosenthal: None. C.S. Almond: None. S.A. Hollander: None. M. Desai: None. D.B. McElhinney: None.
- © 2016 by American Heart Association, Inc.