Introduction: In Liver Transplantation (LT), the average age of both donor and recipient have been steadily increasing in the last years. However, the effect of the interaction of donor and recipient age on outcomes after LT is poorly understood, resulting in non-uniform matching strategies across centers. We explore the effect of donor and recipient age interaction and its impact on patient and graft survival after LT.
Methods: The relationship between donor, recipient demographics, transplant characteristics, and patient and graft survival were explored at uni- and multivariable Cox regression in 849 consecutive LT performed between 1/2000-12/2015. The variable ‘age’ was introduced in the model as both continuous and categorical. Data are expressed as median (IQR).
Results: Donor age was 52y (41-62) and 12% were Donation after Circulatory Death donors with a total Warm Ischemia Time of 19min (15-25). Recipients, aged 57y (49-64), were transplanted with a labMELD of 15 points (11-23) for HCC (30%) and post-ethyl cirrhosis (21%) as main indication. With a median follow-up of 11.4y (95%CI: 10.9-11.9) patient and graft survival at 5y was 75.6% and 71.5%, respectively. Donor age had no impact on patient and graft survival after LT, in particular donor older than 70y did not influence long-term outcomes (HR: 0.87, 95%CI: 0.54-1.39, p=0.55 for patient survival; HR: 0.78, 95%CI: 0.50-1.19, p=0.25 for graft survival). Recipient age independently increased the risk of death after transplantation (HR: 1.03, 95%CI 1.02-1.05, p=0.0001), but the interaction product of donor and recipient age was irrelevant (HR: 1; 95%CI: 0.99-1.001, p=0.88). The adjusted negative effect of recipient age on patient survival was significant already at 6 months (HR: 1.06, 95%CI: 1.03-1.09, p=0.0001) and at 1y post-LT (HR: 1.05, 95%CI: 1.03-1.08; p<0.0001). After stratification of recipient age, the adjusted risk of death became significant for patients aged 61-70y (HR: 1.84, 95%CI: 1.24-2.74, p=0.003) and maximal for recipients older than 70y (HR: 1.96, 95%CI: 1.03-3.72, p=0.04). Matching donors older than 70y to recipients older than 70y did not vary the risk of death (HR: 0.49, 95%CI: 0.17-1.39, p=0.18). Graft survival was not affected by recipient age (HR: 1, 95%CI: 0.93-1.05, p=0.89).
Discussion: recipient age, and not donor age, is an independent risk factor for patient’s death after LT and every 10y increases the risk by 30%. In particular, recipients older than 70y have an almost 2-fold risk of dying. Although older patients might have shorter life expectancy, the negative effect of recipient age is significant already at 6 month post-LT. Age might be irrelevant in the decision making while matching donors and recipients as no synergic interaction was observed. Conclusions: older donors are safe but recipients older than 70y have a risk of death post-LT almost doubled. Strategies matching young donors to older recipients do not reduce their increased risk of death.