Graft Rejection and Survival in Patients Undergoing Multi-Organ Heart Transplantation

Abstract

Purpose Graft rejection and related complications remain leading causes of death in heart transplantation. Here we compare rates of graft rejection and survival in the following transplantation groups: heart-only, heart-lung, heart-kidney, and heart-liver. Methods Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research Database, we retrospectively reviewed heart transplants performed from January 1988 to September 2020. Graft survival was assessed with Kaplan-Meier method and compared by log-rank test. Univariate and multivariate Cox regression analyses were performed to assess hazard ratios. Rejection rates were compared with logistic regression. Results A total of 80,058 patients were included in this study. We found increased risk of graft failure in heart-lung patients and reduced risk in heart-kidney and heart-liver transplants: HR 1.87 (95% 1.75-1.99, p <0.001), HR 0.89 (95% 0.82-0.96, p <0.01), and 0.80 (95% 0.66-0.98, p <0.05), respectively. Rejection rates were lowest in heart-liver transplants, followed by heart-kidney, and heart-lung transplants: OR 0.88 (95% 0.85-0.92, p <0.001), OR 0.91 (95% 0.9-0.93, p <0.001), and OR 0.96 (95% 0.93-1, p <0.05), respectively. These results were consistent in multivariate analysis. Adjusting for donor age, recipient age, and ethnicity found increased risk of graft failure in heart-lung recipients while heart-kidney and heart-liver recipients possessed lower risk: HR 2.01 (95% 1.88-2.14, p <0.001), HR 0.84 (95% 0.78-0.91, p<0.001), and HR 0.80 (95% 0.65-0.97, p <0.05), respectively. Conclusion Heart-lung graft survival is significantly depressed in relation to all other examined groups. Rejection rates are lowest in heart-liver transplants, though all multi-organs showed reduced risk relative to heart-only transplants. More studies are needed to account for confounding and validate these findings prospectively. Graft rejection and related complications remain leading causes of death in heart transplantation. Here we compare rates of graft rejection and survival in the following transplantation groups: heart-only, heart-lung, heart-kidney, and heart-liver. Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research Database, we retrospectively reviewed heart transplants performed from January 1988 to September 2020. Graft survival was assessed with Kaplan-Meier method and compared by log-rank test. Univariate and multivariate Cox regression analyses were performed to assess hazard ratios. Rejection rates were compared with logistic regression. A total of 80,058 patients were included in this study. We found increased risk of graft failure in heart-lung patients and reduced risk in heart-kidney and heart-liver transplants: HR 1.87 (95% 1.75-1.99, p <0.001), HR 0.89 (95% 0.82-0.96, p <0.01), and 0.80 (95% 0.66-0.98, p <0.05), respectively. Rejection rates were lowest in heart-liver transplants, followed by heart-kidney, and heart-lung transplants: OR 0.88 (95% 0.85-0.92, p <0.001), OR 0.91 (95% 0.9-0.93, p <0.001), and OR 0.96 (95% 0.93-1, p <0.05), respectively. These results were consistent in multivariate analysis. Adjusting for donor age, recipient age, and ethnicity found increased risk of graft failure in heart-lung recipients while heart-kidney and heart-liver recipients possessed lower risk: HR 2.01 (95% 1.88-2.14, p <0.001), HR 0.84 (95% 0.78-0.91, p<0.001), and HR 0.80 (95% 0.65-0.97, p <0.05), respectively. Heart-lung graft survival is significantly depressed in relation to all other examined groups. Rejection rates are lowest in heart-liver transplants, though all multi-organs showed reduced risk relative to heart-only transplants. More studies are needed to account for confounding and validate these findings prospectively.