Predictors of Long-Term Outcomes After Liver Transplantation Depending on the Length of Cold Ischemia Time

• Overall survival after liver transplantation is worse when the cold ischemia time (CIT) exceeds 496 minutes. • In patients with CIT ≥496 minutes who are aged >60 years, the number of transfused red blood cells and fresh frozen plasma have been shown to be risk factors for worse survival. • Interestingly, the predictors that were not CIT dependent were the recipient model for end-stage liver disease, body mass index, and donor variables (age, sodium level, and transaminase activities). Cold ischemia time (CIT) is one of the most significant variables affecting graft survival after liver transplantation. The aim of this study was to identify other predictors of worse graft survival depending on the duration of cold ischemia. This retrospective cohort study included data of liver transplant recipients and donors in the period from 2014 to 2019. A total of 724 patients were analyzed after excluding retransplatations and urgent operations. Using receiver operating characteristic analysis, we identified CIT value which divides into 2 clinically different subgroups with respect to 5-year graft loss. Within those 2 subgroups, we performed Cox proportional hazard analysis with time to graft loss as endpoint. The optimal cut-off point for CIT was identified as 496 minutes. Model of end-stage liver disease score, recipient body mass index, and donor sodium concentration showed no significant effect on time to graft loss in either subgroup. For 3 factors we observed a significant effect on time to graft loss in subgroup CIT ≥496 min: transfused red cell concentrate units (hazard ratio [HR] 1.05; 95% confidence interval [CI] 1.00-1.09; P = .02), transfused fresh frozen plasma units (HR 1.04; 95% CI 1.00-1.08; P = .08), and a recipient age of >60 years (HR 1.81; 95% CI 1.10-2.98; P = .02). Predictive ability of well-known risk factors for worse outcomes after liver transplantation depend on the length of cold ischemia.