Nationwide Variability in the Use of Induction Immunosuppression for
Adult Heart Transplantation
Abstract
Background: Institutional factors have been shown to impact outcomes
following orthotopic heart transplantation (OHT). This study evaluated
center variability in the utilization of induction therapy for OHT and
its implications on clinical outcomes. Methods: Adult OHT patients
between 2010 and 2018 were identified from the UNOS registry. Transplant
centers were stratified based on their rates of induction therapy
utilization. Mixed-effects logistic regression models were created with
drug-treated rejection within 1-year as primary endpoint and individual
centers as random parameter. Risk-adjusted Cox regression was used to
evaluate patient-level mortality outcomes. Results: In 17,524 OHTs
performed at 100 centers, induction therapy was utilized in 48.6%
(n=8411) with substantial variability between centers (IQR 21.4 –
79.1%).There were 36, 30, and 34 centers in the low (<29%),
intermediate (29-66%), and high (>67%) induction
utilization terciles groups, respectively. Induction therapy did not
account for the observed variability in the treated rejection rate at
1-year among centers after adjusting for donor and recipient factors
(p=0.20). No differences were observed in postoperative outcomes among
induction utilization centers groups (all, p>0.05).
Furthermore, there was a weak correlation between the percentage of
induction therapy utilization at the center-level and recipients found
to have moderate (r=0.03) or high (r=0.04) baseline risks for acute
rejection at 1-year. Conclusions: This analysis demonstrates there is
substantial variability in the use of induction therapy among OHT
centers. In addition, there was a minimal correlation with baseline
recipient risk or 1-year rejection rates, suggesting a need for
better-standardized practices for induction therapy use in OHT.