Use of extended criteria donor hearts in combined heart-kidney transplant confers greater risk of mortality

Abstract

Extended criteria donors (ECD) hearts have demonstrated acceptable outcomes in select populations. However, their use in patients undergoing simultaneous heart-kidney transplantation (SHKT) has not been explored. This study is assessed the effect of ECD hearts in patients undergoing SHKT vs isolated heart transplants (IHT). The United Network for Organ Sharing (UNOS) database was queried for all adult patients undergoing IHT and SHKT. Patients were stratified by receipt of ECD heart, defined as donor hearts failing to meet established acceptable use criteria. Interaction effects between ECDs and simultaneous kidney transplants were generated. Postoperative outcomes, risk factors, and patient/graft survival were compared across cohorts using Fine-Gray, Kaplan Meier, and Cox Proportional Hazards analyses. Among 26,207 patients included, 1,766 (7%) underwent SHKT. ECD hearts were used in 25% of both IHT and SHKT cohorts. Five-year survival among SHKT/ECD patients (67.3%) was reduced (p < 0.01) compared to SHKT/SDC (80.3%), IHT/ECD (78.1%) and IHT/SCD (80.0%) groups. Among SHKT patients, use of ECD hearts was associated with increased risk (SHR: 1.48; p < 0.01) of renal graft failure compared to SCD hearts. Among SHKT patients, receipt of an ECD heart, and individual ECD criteria (coronary disease and size mismatch >20%), predicted mortality. The interaction effect of receiving both ECD and SHKT predicted mortality and graft failure (HR 1.43; p < 0.01). Patients undergoing SHKT with an ECD heart face greater risks of mortality and graft failure in comparison to those undergoing IHT with ECD hearts. Careful selection of donor organs should be applied to this high-risk cohort.