# Kidney Donor Risk Index and Cardiovascular Complications in a Long-Term Follow-Up Observation

## TL;DR

This study shows that the Kidney Donor Risk Index predicts long-term kidney function and cardiovascular complications in European kidney transplant recipients, especially younger patients.

## Contribution

The study validates the KDRI's predictive value for cardiovascular events in a European cohort and highlights its relevance for younger transplant recipients.

## Key findings

- Higher KDRI values correlate with worse early and long-term kidney graft function.
- KDRI quartiles show a significant increasing trend in post-transplant cardiovascular complications in recipients under 50 years old.
- Higher KDRI kidneys are associated with worse recipient survival prognosis despite not being used for allocation in Poland.

## Abstract

Background: The suitability of the Kidney Donor Risk Index (KDRI) has not been fully validated in the European population. The aim of this study was to evaluate the value of the KDRI in predicting kidney graft function and cardiovascular events (CVEs) in a Polish cohort of kidney transplant recipients (KTRs). Methods: In this retrospective study kidney graft function and CVEs were analyzed among 1420 patients transplanted between 1999 and 2017 and followed until 2021. The KDRI was calculated according to the formula proposed by Rao. Patients were assigned into quartiles (Qs) of KDRI values. Results: Patients in Q4 were older, with higher BMI, longer cold ischemia time (CIT), and a greater rate of ischemic heart disease at the transplantation. The KDRI value determined both early and long-term graft function. During a median follow-up period of 91 months, at least one cardiovascular event was noted in 227 (16.0%) kidney transplant recipients. There was a significant increasing trend for the occurrence of post-transplant CV complications along the consecutive KDRI quartiles (χ2 = 7.3; p < 0.01) among kidney transplant patients younger than 50 years at the time of transplantation. Conclusions: The KDRI is an adequate prognostic tool also for the European population. Despite the KDRI not being used for allocation in Poland we found that kidneys with a higher KDRI are allocated to recipients with worse survival prognosis. The quality of kidneys from a deceased donor may be related to the occurrence of post-transplant cardiovascular complications in recipients younger than 50 years at the transplantation, including those without history of comorbidities such as diabetes or cardiovascular disease.