Heart Retransplantation in the Modern Era: Trends in Characteristics and Outcomes

S. Feng¹, A. Kilic², B. Shou¹, A. Kalra¹, A. Oak¹, W. Liu^1
1Divison of Cardiothoracic Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA, Baltimore, Maryland ²The Johns Hopkins Hospital, Baltimore, Maryland

Purpose: Heart retransplantation is a higher risk procedure compared to primary heart transplant (HT). Despite being associated with worse outcomes,1,2 heart retransplantation in the modern era lacks comprehensive trend analysis. Thus, we examined trends in heart retransplant recipient characteristics and outcomes in the United States from 2000 to 2023.

Methods: We identified all adult heart retransplants from 1/1/2000 to 6/30/2023 in the United Network for Organ Sharing database. We categorized retransplants into three “eras” with consideration of the October 2018 allocation criteria change for HT: 1/1/2000-12/31/2010 (Era 1), 1/1/2011-10/17/2018 (Era 2), and 10/18/2018-6/30/2023 (Era 3). Baseline characteristics were compared using Chi-squared testing for categorical variables and Wilcoxon rank-sum tests for continuous variables. One-year post-transplant survival was evaluated using Cox proportional hazards regression. Multivariable analyses were adjusted for demographic and illness severity covariates including recipient age, sex, body mass index, diabetes, smoking history, chronic steroid use, mechanical ventilation, interval after primary transplant, ischemic time, extended donor criteria, dialysis, and waitlist and post-operative extracorporeal membrane oxygenation (ECMO) use.

Results: Of 54,807 heart transplants (HTs), 1,698 (3.1%) were retransplants. Among retransplant recipients (median age=45 years, 64.1% male), median survival was 12.3 years compared to 13.2 years for primary transplant. Over the study period, median body mass index increased from 25.8 kg/m² (IQR 22.5-29.3) to 26.6 kg/m² (23.4-30.3) (p=0.014). Similarly, incidence of diabetes increased from 23% (n=148) to 31% (n=147) (p=0.005). History of malignancy rose from 8% (n=48) to 13% (n=62) (p=0.007). The proportion of retransplants due to primary graft failure and acute rejection decreased from 9.6% (n=61) to 8.7% (n=41) and 4.6% (n=30) to 3.0% (n=14), respectively, while retransplants due to chronic rejection increased from 10.4% (n=67) to 12.7% (n=60). These differences were not significant after multivariable adjustment (p=0.53 and p=0.23, respectively). Hospital length of stay and post-retransplant stroke and dialysis increased significantly (Table). Median time between initial and retransplant increased from 8.9 years (3.9-13.0) to 10.6 years (4.9-16.4) between Eras 1 and 2 (p < 0.001) but remained similar between Eras 2 and 3 (10.6 years vs. 10.5 years, p< 0.001). Compared to Era 1, 1-year survival after heart retransplant improved in Era 3 (aHR 0.53 [95% CI: 0.35-0.80], p=0.003), with no significant difference between Eras 1 and 2 (p=0.608) (Figure).

Conclusion: Overall, one-year survival after heart retransplant improved between 2000-2023, though improvement was not significant between Eras 1 and 2. Median time between initial transplant and retransplant has remained stable since 2018. Post-transplant dialysis and stroke rates have increased significantly since 2000. Further research into factors underlying these trends is necessary.

Identify the source of the funding for this research project: N/A