The modified US heart allocation system improves transplant rates and decreases status upgrade utilization for patients with hypertrophic cardiomyopathy
Section snippets
Study design and population
We performed a retrospective cohort study of adult (≥18 years old) patients listed for single-organ heart transplant between October 17, 2013 and September 4, 2020 using the UNOS database. Repeat heart transplants and patients without HCM were excluded. This study was approved by the University of Pennsylvania Institutional Review Board.
The study population was divided by listing date into two eras. Era 1 spanned October 17, 2013 to October 17, 2018 and Era 2 spanned October 18, 2018 to
Results
During the study period, 648 patients who were listed for heart transplant met inclusion criteria. Era 1 included 436 (67.3%) patients and Era 2 included 212 (32.7%). Of those listed in Era 1, 75 patients crossed into Era 2 while on the waitlist and had their outcomes censored at October 17, 2018. Average follow-up time in Era 1 was greater than in Era 2 (Era 1: 225.5±291.4 vs Era 2: 128.6±150.1 days, p<0.001).
Discussion
In this study, we found that the new UNOS heart allocation system has led to an increase in one-year transplant rates, a decrease in status upgrade utilization, and reduced waitlist times with no significant change in waitlist mortality. Following the implementation, post-transplant survival rates remained high for HCM patients.3 These findings coincide with the goals of the new system, contrary to predictions by experts who raised concerns in the past.8,10
While era-based confounding is
Conclusions
The new UNOS heart allocation system has produced favorable outcomes for patients with hypertrophic cardiomyopathy with significantly improved transplant rates, shortened waitlist times, and reduced need for status upgrades with unchanged waitlist mortality. These patients continued to experience excellent long-term post-transplant outcomes in the new allocation system.
Author contributions
CF, MH, and PA conceived the project. CF, with support from MH, designed the study, carried out the analysis, and drafted the manuscript. All authors aided in interpreting the results, revising manuscript drafts, and contributed to the final manuscript.
Disclosure statement
The authors have no financial disclosures or conflicts of interest.
Acknowledgments
The authors have no funding or other acknowledgements.
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