Machine perfusion across different donor pathways in heart transplantation: A systematic review and network meta-analysis.

Background: The shortage of donor hearts significantly limits heart transplantation. Innovative machine perfusion strategies have emerged to address the shortcomings of traditional static cold storage after brain death (SCS-DBD), potentially enhancing outcomes and broadening donor eligibility. We performed a systematic review and network meta-analysis to compare the effectiveness of heart transplantation using machine perfusion techniques with conventional SCS-DBD.

Methods: The MEDLINE, Embase, and PubMed databases were systematically searched for articles published between January 2024 and March 2025. Additional relevant studies from 2014-2023 were identified through previous systematic reviews and reference lists. Included were randomized clinical trials and nonrandomized studies evaluating outcomes of heart transplantation methods utilizing hearts from donors after brain death (DBD) and donors after circulatory death (DCD). Meta-analysis was performed examining 30-day and 1-year survival, acute rejection, and primary graft dysfunction.

Results: From 1,758 screened records, 19 studies involving 22,029 patients met the inclusion criteria. No significant differences in 30-day mortality were observed between preservation methods. At 1 year, direct procurement with perfusion of DCD (risk ratio [RR] 0.63 [95% credible interval [CrI] 0.45-0.89]; high certainty) and normothermic regional perfusion of DCD (RR 0.68 [CrI 0.47-0.96]; low certainty) significantly reduced mortality compared with SCS-DBD. Among DBD groups, no mortality differences emerged. Hypothermic oxygenated machine perfusion of DBD significantly reduced severe primary graft dysfunction compared with SCS-DBD (0.27 [0.10-0.63]; high certainty), but acute rejection rates were similar across all methods.

Conclusions: Outcomes of machine perfusion strategies appear noninferior to those of the conventional SCS, proving its potential to broaden the donor pool.