Evaluating outcomes of preemptive kidney transplant in patients over 65 using high-KDPI kidneys compared to non-preemptive recipients

Background: Utilizing kidneys with a Kidney Donor Profile Index (KDPI) score above 85 could be beneficial, especially in End-Stage Kidney Disease (ESKD) patients older than 65. Our study aimed to assess the outcomes of preemptive kidney transplants (KT) in these patients over 65 receiving high KDPI kidneys (≥ 85) and compare the outcomes to the non-preemptive kidney recipients. Methods and materials: This retrospective cohort analyzed the SRTR database for KTs that were performed in the United States from January 2000 to May 2023. This study includes patients older than 65 years old who received only deceased donor KTs, excluding those waitlisted or with prior organ transplants and missing in KDPI scoring. Participants were categorized into four groups: high KDPI preemptive, low KDPI preemptive, high KDPI non-preemptive, and low KDPI non-preemptive. Time-to-event models were used to assess death censored graft loss, and death, adjusting for recipients and donors variables. Results: A total of 47,077 patients aged 65 years and older were included. The median age of the study population was 69 (interquartile rang: 66 – 72) years old and the median follow-up time was 3.1 years. In multivariable Cox regression model, high KDPI non-preemptive transplantation was associated with the worst survival for death censored allograft failure compared to the low KDPI preemptive group, in the presence of confounding variables (HR: 2.89 95% CI: 2.58–3.24). This was followed by the high KDPI preemptive group (HR: 1.88, 95% CI: 1.54–2.30) and low KDPI non-preemptive group (HR: 1.52, 95% CI: 1.37–1.68). Similarly, the high KDPI non-preemptive group had the worst patients’ survival outcomes (HR: 1.80, 95% CI: 1.61–2.02), followed by the low KDPI non-preemptive (HR: 1.47, 95% CI: 1.33–1.63), and the high KDPI preemptive group (HR: 1.28, 95% CI: 1.05–1.57). Conclusion: Older patients can benefit from KT, even when receiving a high-KDPI kidney. Long-term patient survival in older individuals who received high-KDPI kidneys is comparable to low-KDPI recipients. Additionally, preemptive KT led to better outcomes, even in high KDPI cases, underscoring the importance of transplant timing.