Effects of Donor Age and Cold Ischemia on Liver Transplantation Outcomes According to the Severity of Recipient Status

BACKGROUND: Prolonged cold ischemic time (CIT) and increased donor age are well-known factors negatively influencing outcomes after liver transplantation (LT). AIMS: The aim of this study was to evaluate whether the magnitude of their negative effects is related to recipient model for end-stage liver disease (MELD) score. METHODS: This retrospective study was based on a cohort of 1402 LTs, divided into those performed in low-MELD (<10), moderate-MELD (10–20), and high-MELD (>20) recipients. RESULTS: While neither donor age (p = 0.775) nor CIT (p = 0.561) was a significant risk factor for worse 5-year graft survival in low-MELD recipients, both were found to yield independent effects (p = 0.003 and p = 0.012, respectively) in moderate-MELD recipients, and only CIT (p = 0.004) in high-MELD recipients. However, increased donor age only triggered the negative effect of CIT in moderate-MELD recipients, which was limited to grafts recovered from donors aged ≥46 years (p = 0.019). Notably, utilization of grafts from donors aged ≥46 years with CIT ≥9 h in moderate-MELD recipients (p = 0.003) and those with CIT ≥9 h irrespective of donor age in high-MELD recipients (p = 0.031) was associated with particularly compromised outcomes. CONCLUSIONS: In conclusion, the negative effects of prolonged CIT seem to be limited to patients with moderate MELD receiving organs procured from older donors and to high-MELD recipients, irrespective of donor age. Varying effects of donor age and CIT according to recipient MELD score should be considered during the allocation process in order to avoid high-risk matches.