Outcomes of Mechanical Circulatory Support for Severe Primary Graft Dysfunction After DBD versus DCD Heart Transplantation

Abstract

<h3>Purpose</h3> Severe primary graft dysfunction (PGD) is defined by need for mechanical circulatory support (MCS) after heart transplantation. Severe PGD is associated with increased short-term mortality but reported outcomes vary widely. The mechanism of PGD may differ for hearts donated after brainstem-determined death (DBD) and circulatory-determined death (DCD). The purpose of this study was to determine whether there are differences in PGD outcomes between DBD and DCD heart transplants. <h3>Methods</h3> We undertook a retrospective, observational study of all heart transplants performed at our institution since the onset of the DCD heart transplant programme (May 2015 to June 2021). Baseline donor and recipient characteristics were recorded. Outcome measures included duration of MCS, length of intensive care (ICU) stay, total length of hospital stay (LOS) and 90-day mortality. <h3>Results</h3> 280 heart transplants were performed during the study period, including 192 DBD and 88 DCD heart transplants. The overall incidence of severe PGD was 11.8% (n=33). These patients were initially supported with VA ECMO (n=28, 84.9%) or CentriMag RVAD (n=5, 15.1%), of which 6 patients (18.2%) were later converted from ECMO to CentriMag RVAD/BiVAD. The incidence of PGD was similar for DBD (n=21, 10.9%) and DCD (n=12, 13.6%) heart transplants (p=0.541). There were no significant differences in baseline characteristics between DBD and DCD groups. There were no significant differences in outcomes between DBD and DCD groups, including median duration (in days) of MCS (5 vs 6, p=0.679), ICU stay (22 vs 20.5, p=0.881) or total LOS (46 vs 48.5, p=0.454). 90-day mortality was 57.1% in the DBD group and 33.3% in the DCD group (p=0.188). <h3>Conclusion</h3> In one of the world's largest cohorts of DCD heart transplantation, we have not seen a significant difference in PGD incidence or outcomes between DBD and DCD heart transplant patients. The potential lower 90-day mortality in the DCD group may suggest that the natural history of PGD after DCD heart transplantation is more favourable compared with PGD seen after DBD heart transplantation.