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Published on: July 18, 2014
Bridge to Heart Transplant With Temporary Mechanical Circulatory Support: Trends and Outcomes in the 2018 Allocation
Ander Dorken-Gallastegi1, Yeahwa Hong1,2, Nicholas R Hess2
1From the Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Insights
The 2018 UNOS heart policy significantly increased temporary mechanical circulatory support (tMCS) use, leading to reduced waitlist mortality and more heart transplants for patients needing advanced circulatory support.
Area of Science:
- Cardiology
- Transplantation Medicine
- Medical Policy
Background:
- The United Network for Organ Sharing (UNOS) 2018 heart allocation policy was implemented to address high waitlist mortality in patients requiring temporary mechanical circulatory support (tMCS).
- Evaluating the impact of this policy on national trends and patient outcomes is crucial for understanding its effectiveness.
Purpose of the Study:
- To assess national trends in the utilization of tMCS among adult patients waitlisted for isolated heart transplantation.
- To analyze waitlist mortality, transplantation rates, and post-transplant outcomes following the UNOS 2018 policy change.
Main Methods:
- Utilized the UNOS database to identify adult patients waitlisted for isolated heart transplantation between the pre- and post-policy change periods.
- Analyzed the prevalence of tMCS, 90-day waitlist mortality, 90-day transplantation incidence, and 1-year post-transplant mortality.
- Employed adjusted statistical models to compare outcomes between patients on tMCS and those not on support.
Main Results:
- The prevalence of tMCS increased from 7.4% to 22.4% after the 2018 policy change, with a proportional rise in Impella use.
- Patients on tMCS demonstrated significantly lower adjusted odds of waitlist mortality and higher adjusted incidence of transplantation.
- Extracorporeal membrane oxygenation (ECMO) support was associated with the highest 90-day waitlist mortality but also the highest transplantation incidence in the post-policy cohort.
Conclusions:
- The UNOS 2018 heart allocation policy led to a threefold increase in tMCS use as a bridge to heart transplantation.
- tMCS utilization under the new policy is associated with improved waitlist survival and increased transplant rates.
- While ECMO presents higher risks, it also facilitated transplantation for critically ill patients under the revised policy.
Abstract:
The United Network for Organ Sharing (UNOS) 2018 heart allocation policy prioritizes patients receiving temporary mechanical circulatory support (tMCS) given the high waitlist mortality rate of this group. This study evaluates national trends and waitlist outcomes for patients receiving tMCS under the UNOS 2018 allocation policy. Adult patients waitlisted for isolated heart transplantation were included using the UNOS database. The prevalence of tMCS, 90 day waitlist mortality, 90 day incidence of transplantation, and posttransplant 1 year mortality were analyzed. A total of 27,343 patients were waitlisted during the study period (pre-policy change: 13,004 vs . post-policy change: 14,339). The prevalence of tMCS increased from 7.4% (n: 956) to 22.4% (n: 3,186) after the policy change ( p < 0.001). The use of Impella increased proportionally among tMCS modalities. Patients on tMCS had lower adjusted odds of waitlist mortality ( p < 0.001), higher adjusted incidence of transplantation ( p < 0.001), and similar posttransplant mortality ( p = 0.10) under the 2018 policy. Patients on extracorporeal membrane oxygenation (ECMO) support had the highest odds of 90 day waitlist mortality ( p < 0.05) but also the highest incidence of transplantation in the post-policy change cohort ( p < 0.05). In conclusion, the use of tMCS as bridge to heart transplantation increased threefolds and is associated with lower waitlist mortality and higher incidence of transplantation following the UNOS 2018 allocation policy change.
