Comparison of survival outcomes in preemptive versus non-preemptive kidney transplant recipients.

Background: There are conflicting results regarding survival in preemptive versus non-preemptive kidney transplant recipients. The present study aimed to estimate the risk of death in preemptive versus non-preemptive kidney transplant recipients.

Materials and methods: In the present retrospective cohort study, all end-stage renal disease (ESRD) patients who underwent kidney transplantation between 1996 and 2021 in referral kidney transplantation centers in Isfahan province were investigated. In total, 499 patients who received dialysis before kidney transplantation (non-preemptive) and 168 patients who received no dialysis before kidney transplantation (preemptive) were included in the final analysis. Data regarding demographic and clinical variables including sex, age, body mass index (BMI), follow-up duration, immunosuppressive regimen change, kidney donor type, underlying causes of ESRD, and comorbidities before and after kidney transplantation were collected.

Results: The mean age was 55.47 ± 15.53 years in preemptive and 54.87 ± 14.69 years in non-preemptive patients (P = 0.65). Mortality rates were 24.44/1000 person-years of follow-up for preemptive and 18.25/1000 person-years of follow-up for non-preemptive patients (P = 0.013). In the crude model of Cox regression analysis, preemptive kidney transplant recipients had a significantly higher risk of mortality compared to non-preemptive kidney transplant recipients (hazard ratio [HR] = 1.59; 95% confidence interval [CI]: 1.09-2.33; P = 0.015). However, the association attenuated and became insignificant after adjustment for confounders, including age, BMI, immunosuppressive regimen change, kidney donor type, and comorbidities (HR = 1.35; 95% CI: 0.92-1.99; P = 0.12).

Conclusion: The results of the present study indicated that there is no independent association between preemptive kidney transplantation and increased risk of mortality.