Outcomes of Induction Therapy with Rabbit Anti-Thymocyte Globulin in Heart Transplant Recipients: A Single Center Retrospective Cohort Study

Abstract

BackgroundInduction immunosuppression is used in transplantation to prevent early acute rejection. The survival benefit of rabbit anti-thymocyte globulin (rATG) induction has not been established yet. We sought to determine the role of rATG in preventing rejection and improving overall survival.Material/MethodsA retrospective cohort study was conducted from 2005 to 2009 and data of consecutive 268 heart transplant recipients were reviewed.ResultsThe data of 144 patients who received induction with rATG were compared to 124 patients who did not. Although overall survival was not different between the 2 groups (P=0.12), there was a significant difference in restricted mean survival time (RMST) at 5 years (RMST=4.8 months; 95% CI: 1.0–8.6, P=0.01) and 10 years (RMST=10.4 months; 95% CI: 1.6–19.3, P=0.02) in favor of the non-induced patients. No difference was observed between induced and non-induced patients who developed de novo donor specific antibodies. There was a significant difference in median days to first rejection in favor of the induced group (P<0.001).ConclusionsInduction with rATG adds no survival benefit in heart transplant recipients. Patients who did not receive induction therapy had higher life expectancy at 5 years and 10 years. Although there was significant delay in the first rejection episode in favor of the rATG induced group, no difference was observed in donor specific antibodies. This study indicates a need for separate analysis of peri-transplantation co-morbidities and mainly the incidence of acute kidney injury, which could affect long-term survival.

Retrospective Evaluation of Rabbit Antithymocyte Globulin Induction in Heart Transplant Patients

“…Compared with previous studies, it contained more granular data to examine the differences in efficacy and safety for various rATG doses in heart transplantation. 14,18,19,20 There was no difference between the overall incidence of any grade ACR between partial or full induction. Furthermore, there was no statistically significant difference in the cumulative incidence of ACR grade ≥2 between partial and full rATG induction; however, there appears to be a trend toward more rejection grade ≥2 with total rATG doses <4.5 mg/kg, which may have been influenced by the higher incidence of grade 3A rejection seen with partial rATG induction.…”

“…A trend toward higher mortality was similarly seen for patients who received <4.5 mg/kg of rATG (HR 1.56, 95% CI: 0.95-2.56). 14 Jarmi et al 19 also demonstrated no survival difference when comparing rATG induction to no induction.…”

“…Compared with previous studies, it contained more granular data to examine the differences in efficacy and safety for various rATG doses in heart transplantation. 14 , 18 , 19 , 20 …”

Rabbit Antithymocyte Globulin Induction in Heart Transplant Recipients at High Risk for Rejection

“… 7 , 11 Moreover, reports from 2018 and 2019 suggest increased mortality with the use of LDA induction with rATG. 12 , 13 Of interest will be the results of an ongoing pilot randomized study of LDA induction with rATG in heart transplantation (NCT03292861). 19 Thus, as of May 2020, conflicting data supporting its use and its high cost explain why LDA induction is not universally adopted.…”