Early elevated donor-derived cell-free DNA levels in heart transplant recipients following precision-controlled cardiac transport system or ice-cooled organ transport.

Abstract

Recent innovations in temperature-controlled cardiac transportation allow for static hypothermic preservation of transplant organs during transportation. We assessed differences in donor-derived cell-free DNA (dd-cfDNA) using the SherpaPak cardiac transport system (SCTS) and traditional ice transportation. Single-organ heart transplant recipients between January 2020 and January 2022 were included if they had dd-cfDNA measures ≤6weeks post-transplant along with the baseline biopsy at 6weeks as part of the surveillance protocol and no biopsy-confirmed rejection ≤90 days. Elevated dd-cfDNA ≥.20% were compared between groups using logistic regression including a subject effect. Of 65 hearts transplanted, 30 were transported with SCTS and 35 on ice. Recipient characteristics were similar between groups. Donors in the SCTS group were older (34vs. 40 years, p=.04) with a longer total ischemic time (171vs. 212 min, p=.002). Recipients in the SCTS group had a greater risk of elevated dd-cfDNA unadjusted and adjusted for donor age, and prolonged ischemic times>3.5h (Unadjusted odds ratio: 4.9, 95%-CI: 1.08-22.5, p=.039 and Adjusted odds ratio: 5.5, 95%-CI: 1.03-29.6, p=.046). Primary graft dysfunction rates and 1-year mortality were comparable between groups. Elevated dd-cfDNA in patients procured with SCTS may indicate that graft injury was not negated relative to ice transport. However, there were no clinical differences noted in short or long-term outcomes including mortality despite a longer ischemic time in the SCTS group.