ISHLT Response to OPTN Proposal to Establish Comprehensive Multi-Organ Allocation Policy

Published 1 October 2025

• OPTN Comment

The International Society for Heart and Lung Transplantation (ISHLT) appreciates the opportunity to review the OPTN proposal “Establish Comprehensive Multi-Organ Allocation Policy.” This initiative represents a significant advancement in the effort to ensure equitable access to transplantation for patients requiring multiple organs.

The proposal outlines a structured prioritization framework based on medical urgency and access to life-sustaining technologies. Specifically, it prioritizes candidates in the following order: Liver Status 1A (adult and pediatric), Heart Status 1/Pediatric 1A, Liver Status 1B, and Lung candidates with a Composite Allocation Score (CAS) exceeding 41 for O donors and 37 for non-O donors.

ISHLT commends OPTN for its thoughtful approach, supports the overarching goals of the proposal and recommends the following improvements:

1. Pulmonary Disease-Driven Multi-Organ Needs
   The proposal demonstrates that candidates requiring lung or heart-lung transplants with high medical urgency scores face elevated risks of death or delisting. Data presented (e.g., Figure 7) indicate that these patients may have mortality risks exceeding those of Heart Status 1 candidates. ISHLT recommends that the committee consider using the medical urgency score, rather than the full CAS, to determine when lung allocation should trigger dual-organ prioritization. This adjustment would enhance alignment with clinical urgency and reduce reliance on blood type stratification.
2. Limitations of the CAS Framework
   The current use of the full CAS score introduces complexity and may not accurately reflect patient acuity, particularly as scores can paradoxically decline as patients deteriorate. Transitioning to urgency-based scoring would eliminate the need for differential thresholds by blood type and better reflect clinical realities. This approachmay be further refined as other organ systems adopt continuous distribution models.
3. Risk Assessment for Specific Patient Populations
   ISHLT urges further evaluation of how well the CAS and urgency measures capture risk in patients with right ventricular (RV) failure due to pulmonary arterial hypertension (PAH) or congenital heart disease. These populations may be underrepresented in current scoring methodologies, necessitating ongoing refinement to improve risk discrimination.
4. Implementation and Monitoring
   Given the inherent complexity of the proposed multi-organ allocation system, ISHLT recommends the development of predictive modeling to assess potential outcomes prior to implementation. Additionally, a clearly defined post-implementation monitoring strategy should be established. Pilot testing with select organ procurement organizations (OPOs) may prove beneficial in evaluating operational workflows. A contingency protocol should also be available to guide allocation during IT system downtimes.
5. Guidance for Exhausted Allocation Tables
   ISHLT suggests that the proposal be supplemented with guidance for OPOs on procedures to follow when allocation tables are exhausted, ensuring consistency and transparency in decision-making.

Conclusion
ISHLT expresses its support for the proposal and acknowledges the substantial effort invested by OPTN in its development. The recommendations outlined above are intended to strengthen the policy’s clinical applicability, equity, and operational feasibility.