Effect of the UNOS policy change on rates of rejection, infection and hospital readmission following heart transplantation.

BACKGROUND: The 2018 adult heart allocation policy sought to improve waitlist risk stratification, reduce waitlist mortality and increase organ access. This system prioritized patients at greatest risk for waitlist mortality, especially individuals requiring temporary mechanical circulatory support (tMCS). Post-transplant complications are significantly higher in patients on tMCS before transplantation, and early post-transplant complications impact long-term mortality. We sought to determine if policy change affected early post-transplant complication rates of rejection, infection and hospitalization.

METHODS: We included all adult, heart-only, single-organ heart transplant recipients from the UNOS registry with pre-policy (PRE) individuals transplanted between 11/1/2016 to 10/31/2017 and post-policy (POST) between 11/1/2018 to 10/31/2019. We used a multivariable logistic regression analysis to assess the effect of policy change on post-transplant rejection, infection, and hospitalization. Two COVID-19 eras (2019-2020, 2020-2021) were included in our analysis.

RESULTS: The majority of baseline characteristics were comparable between PRE and POST era recipients. The odds of treated rejection (p=0.8), hospitalization (p=0.69), and hospitalization due to rejection (p=0.76) and infection (p=0.66) were similar between PRE and POST eras; there was a trend towards reduced odds of rejection (p=0.08). In both COVID eras, there was a clear reduction in rejection and treated rejection with no effect on hospitalization for rejection or infection. Odds of all-cause hospitalization was increased in both COVID eras.

CONCLUSION: The UNOS policy change improves access to heart transplantation for higher acuity patients without increasing early post-transplant rates of treated rejection or hospitalization for rejection or infection, factors which portend risk for long-term post-transplant mortality.