Abstract 15622: Cost-Effectiveness of Pediatric Heart Transplantation Across a Positive Crossmatch

Abstract

Introduction: Allosensitized children listed with a requirement for a negative prospective crossmatch (XM) have a high risk of death awaiting heart transplantation (HTx). Previously we found that acceptance of the first suitable organ offer for these patients, regardless of the possibility of a +XM, results in a survival benefit at all times after listing, including post-HTx. The cost-effectiveness of this strategy is unknown. Methods: We used a Markov-state transition model with a 10 yr time horizon to compare survival, costs, and utility (i.e. quality of life) for 2 waitlist strategies for sensitized candidates: requiring a negative prospective XM (WAIT) vs. accepting the first suitable organ offer (TAKE). Model data were derived from OPTN status 1A pediatric HTx listings from 1999-2009, the PHTS and HCUP KIDS databases, and other published sources. We assumed no possibility of a +XM in the wait strategy and that the probability of a +XM in the take strategy was equal to the pre-transplant PRA. Results: At base case, TAKE was dominant; it cost less ($122,856) and gained more (1.04) quality-adjusted life-years (QALYs) than WAIT. In sensitivity analyses varying all model parameters individually over clinically plausible ranges, TAKE remained dominant or favored (using a $100,000/QALY cost-effectiveness threshold) except when the probability of HTx for TAKE was <55% over 2 years (base case value 67%). After adjustment of the model so that waitlist probabilities of death and delisting were equal in both strategies (while maintaining the lower probability of HTx associated with WAIT), TAKE remained dominant. WAIT was no longer dominated if mortality after HTx across a +XM was >30%/year (equivalent to median post-HTx survival of <3 yrs); yet even at the extreme assumption of 100% 1-year mortality after HTx across a +XM for TAKE, the wait strategy was not cost effective ($350,097/QALY). CONCLUSIONS: Among sensitized status 1A pediatric HTx candidates, we found that taking the first suitable organ offer is less costly and results in greater survival than awaiting HTx across a negative prospective XM. This suggests that HTx should not be denied based on sensitization status alone.