ISHLT Response to OPTN Modify Heart Policy for Pediatric Candidates and Intended Blood Group Incompatible (ABOi) Offers

Published 8 March 2023

  • Advanced Heart Failure & Transplantation
  • OPTN Comment
  • Pediatrics

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ISHLT Level of Support:
Support the Policy
Read the OPTN Comment

The International Society for Heart and Lung Transplantation (ISHLT) appreciates the opportunity to provide feedback on the “Modify Heart Policy for Intended Incompatible Blood Type (ABOi) Offers to Pediatric Candidates ” OPTN special public comment.

ISHLT Supports this proposal with the following comments:

  • Expanding access to ABO incompatible (ABOi) transplant for heart transplant young children beyond titers of 1:16 and 2 years of age is overdue. Current literature provides evidence for equal outcomes in children beyond current (arbitrary) limits with evidence of partially better outcomes (lower rate of rejection and infection) in young children after ABOi than ABO compatible (ABOc) transplantation. ISHLT supports liberalizing the approach to allow centers to include lower urgency listed patients, generally higher titers (standard approach in Canada up to 1:32 with no mandated limits) and selected patients of higher age and/or titers.
  • In heart transplant, limiting the applicability of ABOi to higher risk patients and the ABOc allocation policy pursued until 2016 in the US disadvantages patients given the shorter wait times (with associated risk of pre-transplant deterioration and complications) especially for blood group O recipients clearly evidenced in recent publications in the US and other jurisdictions.
  • The evidence in pediatric lung and heart lung transplantation is much more limited with very little clinical data published or shared. Liberalizing the policy to include these patients will allow centers to proceed after individual consideration and thereby fortify the evidence basis for this approach to be safe. While there is no immunological reason to assume ABOi lung or heart lung transplant would be less safe than heart alone in young children, at present the available clinical data does not allow a clear conclusion on safety or long-term outcomes for these patients.
  • We recommend the addition of lung non-utilization rates as well as post-transplant survival for ABOi vs ABOc lung and heart-lung recipients to the post-implementation monitoring.