Heart-Kidney and Heart-Liver Transplantation Provide Immunoprotection to the Cardiac Allograft

Abstract

Background: Prior single-center studies suggest that kidney and liver allografts are immunoprotective toward transplanted hearts. The broader effects of the simultaneous transplantation of kidney or liver on protection from rejection are unclear. Methods: The United Network for Organ Sharing database for heart transplantation was queried from 1987 to 2015 and stratified into patients undergoing heart-liver transplantation (HLT) (n = 192), heart-kidney transplantation (HKT) (n = 1,174), and heart-only transplantation (HT) (n = 61,471). Perioperative and follow-up data were compared between HT versus HLT and HT versus HKT groups using analysis of variance (continuous), chi-square test (categorical), and Kaplan-Meier curves (survival). Results: HKT patients were older (51.2 ± 13.4 years of age) compared with HT patients (45.6 ± 19.2 years of age; p < 0.0001), with higher rate of diabetes (33.8% versus 14.8%; p < 0.0001) and dialysis (49.7% versus 2.1%; p < 0.0001). HKT (46.2%) and HLT (49.5%) patients had more urgent need for transplantation (status 1A) compared with HT patients (32%; p < 0.0001). Acute rejection episodes before discharge were lower in the HLT group (7.1% versus 3.1%; p = 0.03). Ten-year patient survivals were similar for HT (53.6%) versus HKT (56.7%) (p = 0.13) versus HLT (60.4%) (p = 0.09). Treatment for rejection during the first posttransplant year was lower in HLT (2.1%) and HKT (8.4%) compared with HT (17.4%) (p < 0.0001 for both). Cox multivariate analysis showed that cardiac allograft survival was improved in HKT (odds ratio, 0.58; 95% confidence interval [CI], 0.49 to 0.70; p < 0.0001). Additionally, HKT (hazard ratio, 0.52; 95% CI, 0.45 to 0.60; p < 0.0001) and HLT (hazard ratio, 0.24; 95% CI, 0.15 to 0.39; p < 0.0001) were associated with improved freedom from rejection. Conclusions: Nationally, HKT and HLT have equivalent postoperative outcomes as HT. Simultaneous kidney or liver transplantation confers an improved clinical and immunologic outcome.