Ice-cold storage or controlled hypothermia to preserve marginal grafts in high-risk heart transplantation

Background: To evaluate the effectiveness of the Paragonix SherpaPak cardiac transport system (PSP) compared to the standard ice-cold storage (ICS) in extended-criteria donor grafts implanted in high-risk recipients. Methods: Data of all HTx at the University Centers of Udine and Bologna, between January 2020 and December 2023, employing extended-criteria donors in high-risk HTx conditions were retrospectively analyzed. Patient outcomes and complications after HTx were assessed. Endomyocardial biopsies were performed in donor hearts immediately after retrieval (T0), before implantation (T1) and at reperfusion (T2) to evaluate signs of myocardial damage. Results: Overall, 90 patients who had heart transplantation (HTx) with a donor graft preserved with either ICS (n = 60) or PSP (n = 30) were included in the study. The 30-day mortality was 3% in both groups (p = 0.99), and 1-year survival 90% and 88% (p = 0.89) for recipients transplanted with PSP and ICS preserved grafts. Rates of moderate-to-severe graft dysfunction and bradi-arrhythmias for PSP and ICS groups were 7% versus 20% (p = 0.08), and 3% versus 15% (p = 0.09). Histologically, severe degrees of cellular and endothelial damage were absent in all PSP grafts while severe degree of contraction bands were higher in ICS hearts at T2. Conclusions: In high-risk donor–recipient matching, donor heart preservation with PSP seems to show a tendency toward better graft protection.