Waitlist mortality and post transplant survival amongst non-extracorporeal membrane oxygenation high-urgency heart transplant recipients before and after the 2018 policy change

Abstract

Objective

The adult heart allocation policy changed from a 3- to 6-tiered system in 2018, more precisely stratifying high-urgency patients. Many studies examined the effects on patients classified as Status 1 or those with implantable devices, especially extracorporeal membrane oxygentation (ECMO), however, few have analyzed other high-urgency cohorts. This study's purpose is to compare waitlist and midterm outcomes of non-ECMO high-urgency patients before and after the policy change.

Methods

All high-risk (Status 1A, 1, 2, 3) non-ECMO adult patients listed for isolated heart transplantation were identified using the United Network for Organ Sharing database and split based on the October 18, 2018, policy change date into era 1 (7/2014-7/2018) and era 2 (1/2019-1/2023). Categorical and continuous variables were assessed using χ² and t tests, respectively. Waitlist mortality was analyzed using competing risk regression whereas Kaplan-Meier curves assessed posttransplant survival.

Results

Candidates from era 2 demonstrated greater rates of comorbidities like pulmonary hypertension (65% vs 67%, P = .007) and greater need for support with inotropes (39% vs 47%, P < .001) and intra-aortic balloon pump (12% vs 42%, P < .001). Yet, candidates from era 2 had significantly decreased waitlist time (71 vs 19 days, P < .001) and waitlist mortality (19% vs 7%, P < .001) whereas Kaplan-Meier 3-year survival (86% vs 85%, P = .42) remained similar.

Conclusions

Among non-ECMO high-urgency heart transplant recipients, candidates from era 2 demonstrated greater clinical acuity but improved waitlist mortality and equivalent midterm survival. These findings reassure that the 2018 policy change did not compromise outcomes amongst this high-urgency cohort, despite favoring patients bridged with ECMO.