KIDNEY DONOR RISK INDEX CORRELATES WITH THE WORSE RECIPIENTS AND GRAFTS SURVIVAL IN A POLISH COHORT

Abstract BACKGROUND AND AIMS Kidney transplant outcomes are the result of a combination of different factors, including donor factors, that influence graft allocation. Kidney Donor Risk Index (KDRI) quantifies the donor risk and is used to predict the outcome of a kidney transplantation from a deceased donor in the US. However, its value in the European populations has not yet been well established. The aim of this retrospective study was to evaluate the correlation between KDRI and recipient cardiovascular events as well as kidney graft and overall survival in a Polish cohort. METHOD We conducted a retrospective single-center cohort study of 813 adult patients who received deceased donor kidney transplant (KTx) at the Hospital of Medical University of Silesia, Katowice, Poland between January 2010 and December 2017 and were followed until December 2021. Living donor recipients as well as multiple organs transplantations were excluded. KDRI was calculated according to formula proposed by Rao and patients were divided into quartiles of KDRI values. Kidney graft function was analyzed using the estimated glomerular filtration rate (eGFR) using MDRD formula at 3, 6 and 12 months after KTx and every 12 months thereafter. Cardiovascular (CVE) events such as cardiac death, stroke, myocardial infarction, and acute coronary syndrome were monitored throughout the study period. The correlation between KDRI and eGFR was calculated using the Pearson test. Kaplan–Meier survival method and Mantel-Cox analysis were performed in order to analyze the impact of the KDRI categories on graft loss, death censored graft survival and patient outcomes (CVE and death from any cause). RESULTS There was no statistical difference in the pretransplant dialysis vintage, duration of pretransplant hypertension, residual diuresis or history of cardio-vascular events between the patients receiving kidneys from different KDRI quartile groups. Patients in Q1 group were significantly younger (47.3 ± 12.8 versus 54.5 ± 12.7 years, P < 0.001) and have a shorter cold ischemia time (16.8 ± 6.5 versus 19.5 ± 6.4 h, P< 0.01) compared with the Q4 KDRI patients. The mean eGFR was significantly higher in the highest KDRI quartile compared with the lowest one throughout the study (66 ± 21 versus 43 ± 16 mL/min, P < 0.001 at month 3; 68 ± 21 versus 44 ± 1 5 mL/min, P < 0.001 at month 12; 66 ± 20 versus 43 ± 14 mL/min, P < 0.001 at month 48, respectively). A significant negative correlation was found between KDRI and eGFR throughout (r = −0.43, P < 0.001 at month 3 to r = −0.45, P < 0.001 at month 48, ). There was a statistically significant difference in death censored kidney graft survival (P = 0.01) among the four KDRI quartile groups displayed with the Kaplan–Meier curves in Figure 1. There was a significant difference in CVE-free survival (P < 0.001) between the quartiles (displayed on the Kaplan–Meier curve in Figure 2). CONCLUSION 1. In patients after kidney transplantation KDRI correlates with the worse graft and patients outcomes. 2. KDRI may be an adequate and valuable prognostic tool for Polish population of kidney graft recipients.