Machine Perfusion for Recovery of Brain Death Donor Hearts From Extended Distances.

The emerging ex vivo machine perfusion (MP) enables the extension of ex situ intervals, potentially expanding the heart transplant (OHT) donor pool. From October 18, 2018, to June 30, 2023, isolated OHT using donation after brain death (DBD) from extended distances (>500 miles) were identified in the United Network for Organ Sharing database, and categorized into cold storage (non-MP, N = 1,212) and MP group (N = 152). The MP utilization rate for DBD hearts from extended distances surged from 0% in 2018 to 27.7% in 2023. Recipient characteristics including listing status were similar except for history of cardiac surgery (non-MP, 32% vs. MP, 41%, p = 0.019). The travel distance was longer in MP group (696 vs. 894 miles, p < 0.001), as was donor organ preservation time (4.42 vs. 6.27 hours, p < 0.001). One-year survival was similar between groups (non-MP, 93.0 ± 0.8% vs. MP, 90.5 ± 2.9%, p = 0.23). In multivariable Cox hazards models, MP was not associated with mortality (hazard ratio, 1.19; p = 0.60). Among MP cohort, survival was comparable between hearts transported between 500-999 miles (N = 112) and those over 1,000 miles (N = 40). The utilization of MP for DBD heart recovery allows for safe DBD recovery from extended distance with comparable survival to cold storage.