Related Experiment Video
Updated: Oct 10, 2026
A Rat Lung Transplantation Model of Warm Ischemia/Reperfusion Injury: Optimizations to Improve Outcomes
Published on: October 28, 2021
The Impact of Composite Allocation Score Implementation on Waitlist Outcomes and Post-Transplant Survival in Lung
Vikram Krishna1, Allen A Razavi1, Brian Lim1
1Department of Cardiac Surgery, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA.
Background:
The Lung Composite Allocation Score (CAS) was implemented in March 2023. While early evaluations showed no adverse effect of CAS on short-term survival for primary transplants, its impact on re-transplantation remains unknown.
Methods:
We identified all adult patients from the United Network of Organ Sharing database who underwent lung transplantation between January 2017 and March 2025. The primary outcomes were one-year post-transplant survival compared between primary and re-transplant recipients and one-year post-transplant survival among re-transplant recipients compared across three eras: Era 1 (2017-2019), Era 2 (2020-March 9, 2023), and Era 3 (CAS, March 9, 2023-March 2025).
Results:
Among 21,569 patients, 665 (3.1%) underwent re-transplantation. Compared to primary transplants, re-transplant recipients required more pre-operative ECMO (8.7% vs 3.6%, p<0.001) and more ventilator support (11.4% vs 2.7%, p<0.001). Re-transplants had significantly worse 1-year survival (79.3% [75.9-82.3] vs 89.2% [88.7-89.6], aHR 2.18 [1.79-2.64], p<0.001). Among re-transplants, there were no differences in 1-year survival across eras (Era 1: 79.4% [73.4-84.2]; Era 2: 79.1% [73.5-83.7], aHR 0.96 [0.63-1.45], p=0.85; Era 3: 80.1% [72.4-85.9], aHR 0.70 [0.42-1.17], p=0.18). The waitlist times across eras were similar (p=0.28). However, Era 3 recipients had longer donor travel distances and longer donor ischemic times (both p<0.001). There were no differences in waitlist mortality or transplant rates for re-transplants between eras (p>0.05).
Conclusions:
Re-transplant rates, waitlist times, and one-year survival were unchanged across eras. However, the limited CAS-era cohort precludes conclusions regarding equivalence, and larger studies with longer follow-up are needed.
