Programmatic Normothermic Machine Perfusion and Association with Liver Transplant Waitlist Outcomes for Patients with Lower Model for End-Stage Liver Disease Score.

Background: Normothermic machine perfusion (NMP) may enhance the use of extended criteria donor livers which might impact waitlist outcomes. Its impact on patients with low Model for End-Stage Liver Disease (MELD) scores, who generally face longer waitlist times, has not been studied. This study aimed to assess the impact of NMP on waitlist and post liver transplantation (LT) outcomes accounting for MELD allocation preference.

Study Design: Adult patients listed for LT at 2 academic centers within the same enterprise (February 4, 2020 to December 31, 2023) were included (1,203; pre-NMP = 635, NMP = 538). Transplant probability and waitlist mortality were analyzed using competing risk analyses.

Results: Patients with listing MELD 20 or less demonstrated improved waitlist time (p < 0.001), transplant incidence (log-rank p < 0.001), and transplant probability (hazard ratio = 1.48, 95% CI 1.29 to 1.71, p < 0.001) with NMP. Open offers were more frequent with NMP and lower MELDs. Low MELD patients demonstrated waitlist cost savings in the NMP era ($36,750 vs $28,867, p = 0.039). Waitlist mortality and post-LT outcomes, survival and costs were not different. Patients with listing MELD greater than 20 demonstrated similar waitlist and posttransplant outcomes and costs in the NMP era. Spline curves show that the lowest MELD patients (<10 points) have experienced the greatest improvement in transplant access. Compared with high MELD, low MELD patients in the NMP era had reduced waitlist mortality (log-rank p < 0.001) and improved post-LT outcomes: inpatient (p < 0.001), 90-day (p = 0.002), and 6-month (p = 0.04) comprehensive complications index.

Conclusions: Programmatic NMP may help improve transplant access for lower MELD patients. This study also supports early transplantation for patients with low MELD scores in the modern era.