Kidney transplantation in older recipients: Preemptive high KDPI kidney vs lower KDPI kidney after varying dialysis vintage

Outcomes Using High KDPI Kidneys in Recipients Over 65 y of Age

BACKGROUND

Kidney transplantation has been shown to improve life expectancy when compared with remaining on dialysis. However, there is an ever-expanding shortage of available organs for transplantation. The use of high kidney donor profile index (KDPI; >85) kidneys is 1 strategy to address this shortage. The current study aims to evaluate the advantage of accepting a high KDPI versus a low KDPI kidney (KDPI ≤85) in patients 65 y or older.

METHODS

A single-center retrospective review of all patients, ages 65 y or older, who underwent deceased donor kidney transplantation between 2010 and 2020 was performed. Outcomes and wait times of recipients undergoing low KDPI (KDPI ≤85) versus high KDPI (KDPI >85) kidney transplantation were compared. Significance was defined as P < 0.05.

RESULTS

Four hundred ninety-two patients were identified; 317 (64.4%) were men with a median age at transplantation of 69 y. Four hundred five patients received low KDPI kidneys, whereas the remaining received high KDPI grafts. High KDPI kidneys were procured from older donors (60 versus 47, P < 0.001) and had shorter cold ischemic time (25.0 versus 28.3 h, P = 0.01) compared with low KDPI kidneys. There was no significant difference in graft and patient survival between low and high KDPI recipients, with 85.1% and 86.2% grafts functioning at a follow-up of 4.85 (2.9-7.0) y, respectively. Pretransplant wait time was significantly shorter in the high KDPI group (2.7 [1.8-4.1] versus 3.5 [2.3-4.8] y; P = 0.004).

CONCLUSIONS

In patients 65 y or older undergoing deceased donor kidney transplantation, high KDPI kidneys may offer shorter pretransplant waiting times without compromising graft or patient survival.

The Use of Kidneys With Lower Longevity From Deceased Donors to Improve Access to Preemptive Renal Transplantation for Elderly Patients: A Qualitative Study

Background

There is a gap between the number of patients waiting for a transplant and the number of kidneys available. Some deceased donor kidneys are currently nonutilized, as medical teams fear that they will experience suboptimal graft survival. However, these organs could provide an acceptable therapeutic option if they were allocated for preemptive kidney transplantation in elderly candidates.

Objective

This project aims to gather patients' perspectives on the allocation of kidneys with lower longevity for preemptive kidney transplantation in elderly patients.

Design

Individual interviews.

Setting

The Center hospitalier de l'Université de Montréal (CHUM) chronic kidney disease (CKD) clinic.

Participants

Patients aged between 64 and 75 years with CKD G4-5 ND, followed at the CHUM and who have not initiated dialysis yet.

Methods

Between March and July 2023, we conducted 14 individual interviews with patients aged between 64 and 75 years who had CKD G4-5 ND and were followed at the CHUM. The interviews were digitally recorded and transcribed. Thematic analysis was conducted.

Results

Most participants were in favor of using kidneys with lower longevity to increase their access to transplantation, improve their quality of life, enable accelerated transplantation, and avoid dialysis. Patients also wanted to be engaged in the decision-making process, underlining the importance of informed consent. Although the use of kidneys with lower longevity offers the hope of returning to "normal" life, some patients were concerned about the risk of reduced graft survival and the need for a subsequent kidney transplant. In these cases, patients were interested in using mitigation strategies, such as prioritization for kidney transplantation from standard donors in case of early graft loss associated with receiving kidneys with lower longevity. They also recommended the development of a separate waiting list for patients consenting to preemptive transplantation with kidneys with lower longevity.

Limitations

This study was conducted in only 1 nephrology clinic in the province of Quebec with French-speaking patients. Consequently, the results may not be generalizable to other populations, including ethnic minorities.

Conclusion

The use of kidneys with lower longevity for preemptive kidney transplantation appears to be an interesting option for elderly kidney transplant candidates. However, patient information and participation in the decision-making process are essential. Moreover, organ donation organizations and transplant programs should develop a separate waitlist for transplant candidates who have preconsented to receive organ offers of deceased donor kidneys with lower longevity.

Trial registration

Not registered.

Expanding Access to High KDPI Kidney Transplant for Recipients Aged 60 y and Older: Cost Utility and Survival

Background

Modern organ allocation systems are tasked with equitably maximizing the utility of transplanted organs. Increasing the use of deceased donor organs at risk of discard may be a cost-effective strategy to improve overall transplant benefit. We determined the survival implications and cost utility of increasing the use of marginal kidneys in an older adult Canadian population of patients with end-stage kidney disease.

Methods

We constructed a cost-utility model with microsimulation from the perspective of the Canadian single-payer health system for incident transplant waitlisted patients aged 60 y and older. A kidney donor profile index score of ≥86 was considered a marginal kidney. Donor- and recipient-level characteristics encompassed in the kidney donor profile index and estimated posttransplant survival scores were used to derive survival posttransplant. Patients were followed up for 10 y from the date of waitlist initiation. Our analysis compared the routine use of marginal kidneys (marginal kidney scenario) with the current practice of limited use (status quo scenario).

Results

The 10-y mean cost and quality-adjusted life-years per patient in the marginal kidney scenario were estimated at $379 485.33 (SD: $156 872.49) and 4.77 (SD: 1.87). In the status quo scenario, the mean cost and quality-adjusted life-years per patient were $402 937.68 (SD: $168 508.85) and 4.37 (SD: 1.87); thus, the intervention was considered dominant. At 10 y, 62.8% and 57.0% of the respective cohorts in the marginal kidney and status quo scenarios remained alive.

Conclusions

Increasing the use of marginal kidneys in patients with end-stage kidney disease aged 60 y and older may offer cost savings, improved quality of life, and greater patient survival in comparison with usual care.

Predicting Kidney Transplantation Outcomes from Donor and Recipient Characteristics at Time Zero: Development of a Mobile Application for Nephrologists

(1) Background: We report on the development of a predictive tool that can estimate kidney transplant survival at time zero. (2) Methods: This was an observational, retrospective study including 5078 transplants. Death-censored graft and patient survivals were calculated. (3) Results: Graft loss was associated with donor age (hazard ratio [HR], 1.021, 95% confidence interval [CI] 1.018-1.024, p < 0.001), uncontrolled donation after circulatory death (DCD) (HR 1.576, 95% CI 1.241-2.047, p < 0.001) and controlled DCD (HR 1.567, 95% CI 1.372-1.812, p < 0.001), panel reactive antibody percentage (HR 1.009, 95% CI 1.007-1.011, p < 0.001), and previous transplants (HR 1.494, 95% CI 1.367-1.634, p < 0.001). Patient survival was associated with recipient age (> 60 years, HR 5.507, 95% CI 4.524-6.704, p < 0.001 vs. < 40 years), donor age (HR 1.019, 95% CI 1.016-1.023, p < 0.001), dialysis vintage (HR 1.0000263, 95% CI 1.000225-1.000301, p < 0.01), and male sex (HR 1.229, 95% CI 1.135-1.332, p < 0.001). The C-statistics for graft and patient survival were 0.666 (95% CI: 0.646, 0.686) and 0.726 (95% CI: 0.710-0.742), respectively. (4) Conclusions: We developed a mobile app to estimate survival at time zero, which can guide decisions for organ allocation.

Evaluating Cost-Effectiveness in Using High-Kidney Donor Profile Index Organs

A more granular donor kidney grading scale, the kidney donor profile index (KDPI), has recently emerged in contradistinction to the standard criteria donor/expanded criteria donor framework. In this paper, we built a Markov decision process model to evaluate the survival, quality-adjusted life years (QALY), and cost advantages of using high-KDPI kidneys based on multiple KDPI strata over a 60-month time horizon as opposed to remaining on the waiting list waiting for a lower-KDPI kidney. Data for the model were gathered from the Scientific Registry of Transplant Recipients and the United States Renal Data System Medicare parts A, B, and D databases. Of the 129,024 phenotypes delineated in this model, 65% of them would experience a survival benefit, 81% would experience an increase in QALYs, 87% would see cost-savings, and 76% would experience cost-savings per QALY from accepting a high-KDPI kidney rather than remaining on the waiting list waiting for a kidney of lower-KDPI. Classification and regression tree analysis (CART) revealed the main drivers of increased survival in accepting high-KDPI kidneys were wait time ≥30 months, panel reactive antibody (PRA) <90, age ≥45 to 65, diagnosis leading to renal failure, and prior transplantation. The CART analysis showed the main drivers of increased QALYs in accepting high-kidneys were wait time ≥30 months, PRA <90, and age ≥55 to 65.

Intention-to-treat Analysis of Patients Aged 70 Years and Older Awaiting Kidney Transplantation in Post-Kidney Allocation System Era

BACKGROUND

The US population is aging, and so the number of patients treated for end-stage renal disease is on the rise. In the United States, 38% of people over 65 y old have chronic kidney disease. There continues to be a reluctance of clinicians to consider older candidates for transplant, including early referrals.

METHODS

We conducted a retrospective analysis of the Organ Procurement and Transplantation Network database of all adults ≥70 y old undergoing kidney transplants from December 1, 2014, to June 30, 2021. We compared patient and graft survival in candidates who were transplanted while on hemodialysis versus preemptive with a living versus deceased donor kidney transplant.

RESULTS

In 2021, only 43% of the candidates listed for transplant were preemptive. In an intention-to-treat analysis from the time of listing, candidate survival was significantly improved for those transplanted preemptively versus being on dialysis (hazard ratio 0.59; confidence interval, 0.56-0.63). All donor types, donor after circulatory death, donor after brain death, and living donor, had a significant decrease in death over remaining on the waiting list. Patients who were on dialysis or transplanted preemptively with a living donor kidney had significantly better survival than those receiving a deceased donor kidney. However, receiving a deceased donor kidney significantly decreased the chance of death over remaining on the waiting list.

CONCLUSIONS

Patients ≥70 y old who are transplanted preemptively, whether with a deceased donor or a living donor kidney, have a significantly better survival than those who are transplanted after initiating dialysis. Emphasis on timely referral for a kidney transplant should be placed in this population.

What are the benefits of preemptive versus non-preemptive kidney transplantation? A systematic review and meta-analysis

Opting for a preemptive kidney transplant (PKT) can help avoid costs and morbidity associated with dialysis. However, while multiple studies have shown clinical benefits of PKT, other studies have not demonstrated this, leading to controversy in the literature regarding the exact benefits of PKT. Therefore, this study aimed to determine the clinical outcomes of PKT versus non-preemptive kidney transplantation (nPKT) in adult patients. Multiple databases were searched up to May 4, 2022. Independent reviewers selected studies for inclusion and extracted relevant data. Risk of bias was assessed using the Downs and Black checklist. Eighty-seven studies including 859,715 adult kidney transplant patients were included the review. The risk of patient death (relative risk [95% confidence interval] 0.74 [0.60-0.91]) was significantly lower in PKT versus nPKT patients for living donor (LD) transplants, whereas the risk of overall graft loss was significantly lower in PKT compared to nPKT patients for both LD (0.72 [0.62-0.83]) as well as deceased donor (DD) transplants (0.80 [0.69-0.92]). The evidence suggests that LD PKT patients have a lower risk of patient death and graft loss compared to nPKT patients, and DD PKT patients have a lower risk of graft loss than nPKT patients.

Preemptive living donor kidney transplantation: Access, fate, and review of the status in Egypt

BACKGROUND

Preemptive living donor kidney transplantation (PLDKT) is recommended as the optimal treatment for end-stage renal disease.

AIM

To assess the rate of PLDKT among patients who accessed KT in our center and review the status of PLDKT in Egypt.

METHODS

We performed a retrospective review of the patients who accessed KT in our center from November 2015 to November 2022. In addition, the PLDKT status in Egypt was reviewed relative to the literature.

RESULTS

Of the 304 patients who accessed KT, 32 patients (10.5%) had preemptive access to KT (PAKT). The means of age and estimated glomerular filtration rate were 31.7 ± 13 years and 12.8 ± 3.5 mL/min/1.73 m2, respectively. Fifty-nine patients had KT, including 3 PLDKTs only (5.1% of total KTs and 9.4% of PAKT). Twenty-nine patients (90.6%) failed to receive PLDKT due to donor unavailability (25%), exclusion (28.6%), regression from donation (3.6%), and patient regression on starting dialysis (39.3%). In multivariate analysis, known primary kidney disease (P = 0.002), patient age (P = 0.031) and sex (P = 0.001) were independent predictors of achievement of KT in our center. However, PAKT was not significantly (P = 0.065) associated with the achievement of KT. Review of the literature revealed lower rates of PLDKT in Egypt than those in the literature.

CONCLUSION

Patient age, sex, and primary kidney disease are independent predictors of achieving living donor KT. Despite its non-significant effect, PAKT may enhance the low rates of PLDKT. The main causes of non-achievement of PLDKT were patient regression on starting regular dialysis and donor unavailability or exclusion.

The Benefits of Preemptive Transplantation Using High-Kidney Donor Profile Index Kidneys

BACKGROUND

The Kidney Donor Profile Index (KDPI) is a percentile score summarizing the likelihood of allograft failure: A KDPI ≥85% is associated with shorter allograft survival, and 50% of these donated kidneys are not currently used for transplantation. Preemptive transplantation (transplantation without prior maintenance dialysis) is associated with longer allograft survival than transplantation after dialysis; however, it is unknown whether this benefit extends to high-KDPI transplants. The objective of this analysis was to determine whether the benefit of preemptive transplantation extends to recipients of transplants with a KDPI ≥85%.

METHODS

This retrospective cohort study compared the post-transplant outcomes of preemptive and nonpreemptive deceased donor kidney transplants using data from the Scientific Registry of Transplant Recipients. 120,091 patients who received their first, kidney-only transplant between January 1, 2005, and December 31, 2017, were studied, including 23,211 with KDPI ≥85%. Of this cohort, 12,331 patients received a transplant preemptively. Time-to-event models for the outcomes of allograft loss from any cause, death-censored graft loss, and death with a functioning transplant were performed.

RESULTS

Compared with recipients of nonpreemptive transplants with a KDPI of 0%-20% as the reference group, the risk of allograft loss from any cause in recipients of a preemptive transplant with KDPI ≥85% (hazard ratio [HR], 1.51; 95% confidence interval [CI], 1.39 to 1.64) was lower than that in recipients of nonpreemptive transplant with a KDPI ≥85% (HR, 2.39; 95% CI, 2.21 to 2.58) and similar to that of recipients of a nonpreemptive transplant with a KDPI of 51%-84% (HR, 1.61; 95% CI, 1.52 to 1.70).

CONCLUSIONS

Preemptive transplantation is associated with a lower risk of allograft failure, irrespective of KDPI, and preemptive transplants with KDPI ≥85% have comparable outcomes with nonpreemptive transplants with KDPI 51%-84%.

Evaluation of technical urinary tract complications in kidney transplantation recipients with a prolonged dialysis history

BACKGROUND

The kidney transplant waiting list continues to expand, resulting in prolonged dialysis times exceeding 8 years before transplantation in some regions. The relationship between long-term dialysis and urinary tract complications after kidney transplant remains largely unexplored. This study aims to evaluate post-kidney transplant complications in patients with a history of prolonged dialysis.

METHODS

A single-center, retrospective cohort study of patients maintained on dialysis ≥8 years before kidney transplant between January 2000 and July 2020 was conducted. Clinical variables, including demographics and comorbidities, were reviewed. The primary objective was the development of a technical urinary tract complication. Secondary outcomes included any postoperative complication by type, stratified by medical and surgical complications.

RESULTS

Overall, 376 patients met the inclusion criteria. The mean pre-kidney transplant dialysis time was 10.2 ± 2.6 years. The majority (65.7%) of the study participants were anuric. Four patients (1.1%) experienced a urine leak, and 8 patients (2.1%) had a ureteral stricture. Any complication was observed in 111 (29.5%) patients, with urinary tract infections being the most common. Urinary catheters remained in place for a median of 4 (3, 5) days. Drains were commonly used (62.8%) for a median of 5 (4, 6) days.

CONCLUSION

In our large, single-center experience with kidney transplants in high-risk patients with prolonged dialysis and anuria, the technical urinary tract complications rate remained low. With the current literature consisting of small cohorts and having relatively short pre-kidney transplant dialysis periods, our analysis addresses the shortcomings of the literature while suggesting that this patient population may not truly be "high risk."

Incidence, predictors, and outcomes of early hospital readmissions after kidney transplantation: Systemic review and meta-analysis

BACKGROUND

Early hospital readmission (EHR) within 30 days after kidney transplantation is a significant quality indicator of transplant centers and patient care. This meta-analysis aims to evaluate the incidence, predictors, and outcomes of EHR after kidney transplantation.

METHODS

We comprehensively searched the databases, including PubMed, Cochrane CENTRAL, and Embase, from inception until December 2021 to identify studies that assessed incidence, risk factors, and outcome of EHR. The outcomes included death-censored graft failure and mortality. Data from each study were combined using the random effect to calculate the pooled incidence, mean difference (MD), odds ratio (OR), and hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

A total of 17 studies were included. The pooled EHR incidence after kidney transplant was 24.4% (95% CI 21.7-27.3). Meta-analysis showed that recipient characteristics, including older recipient age (MD 2.05; 95% CI 0.90-3.20), Black race (OR 1.31; 95% CI 1.11, 1.55), diabetes (OR 1.32; 95% CI 1.22-1.43), and longer dialysis duration (MD 0.85; 95% CI 0.41, 1.29), donor characteristics, including older donor age (MD 2.02; 95% CI 0.93-3.11), and transplant characteristics, including delayed graft function (OR 1.75; 95% CI 1.42-2.16) and longer length of hospital stay during transplantation (MD 1.93; 95% CI 0.59-3.27), were significantly associated with the increased risk of EHR. EHR was significantly associated with the increased risk of death-censored graft failure (HR 1.70; 95% CI 1.43-2.02) and mortality (HR 1.46; 95% CI 1.27-1.67) within the first year after transplantation.

CONCLUSION

Almost one-fourth of kidney transplant recipients had EHR within 30 days after transplant, and they had worse post-transplant outcomes. Several risk factors for EHR were identified. This calls for future research to develop and implement for management strategies to reduce EHR in high-risk patients.

Beyond Graft Survivl: A National Cohort Study Quantifying the Impact of Increasing Kidney Donor Profile Index on Recipient Outcomes 1 Year Post-transplantation

Background.

The reporting of a locally validated kidney donor profile index (KDPI) began in Australia in 2016. Across diverse populations, KDPI has demonstrated utility in predicting allograft survival and function. A metric that incorporates both elements may provide a more comprehensive picture of suboptimal recipient outcomes.

Methods.

A retrospective cohort study of adult kidney transplant recipients in Australia (January 2009 to December 2014) was conducted. Conventional recipient outcomes and a composite measure of suboptimal outcome (1-y allograft failure or estimated glomerular filtration rate [eGFR] <30 mL/min) were evaluated across KDPI intervals (KDPI quintiles and 5-point increments in the KDPI 81–100 cohort). The impact of increasing KDPI on allograft function (1-y eGFR) and a suboptimal outcome was explored using multivariable regression models, adjusting for potential confounding factors.

Results.

In 2923 donor kidneys eligible for analysis, median KDPI was 54 (interquartile range [IQR], 31–77), and Kidney Donor Risk Index was 1.39 (IQR, 1.03–1.67). The median 1-y eGFR was 52.74 mL/min (IQR, 40.79–66.41 mL/min). Compared with the first quintile reference group, progressive reductions in eGFR were observed with increasing KDPI and were maximal in the fifth quintile (adjusted β-coefficient: −27.43 mL/min; 95% confidence interval, –29.44 to –25.42; P < 0.001). A suboptimal outcome was observed in 359 recipients (12.3%). The adjusted odds for this outcome increased across quintiles from a baseline of odds ratio of 1.00 (first quintile) to odds ratio of 11.68 (95% confidence interval, 6.33-21.54, P < 0.001) in the fifth quintile cohort.

Conclusions.

Increases in donor KDPI were associated with higher probabilities of a suboptimal outcome and poorer baseline allograft function, particularly in the KDPI > 80 cohort. These findings may inform pretransplant discussions with potential recipients of high-KDPI allografts.

What Are the Burden, Causes, and Costs of Early Hospital Readmissions After Kidney Transplantation?

Introduction:

Kidney transplant recipients are at risk for complications resulting in early hospital readmission. This study sought to determine the incidences, risk factors, causes, and financial costs of early readmissions.

Design:

This single-centre cohort study included 1461 kidney recipients from 1 Jul 2004 to 31 Dec 2012, with at least 1-year follow-up. Early readmission was defined as hospitalization within 30 or 90-days postdischarge from transplant admission. Associations between various parameters and 30 and 90-days posttransplant were determined using multivariable Cox proportional hazards models. The hospital-associated costs of were assessed.

Results:

The rates of early readmission were 19.4% at 30 days and 26.8% at 90 days posttransplant. Mean cost per 30-day readmission was 11 606 CAD. Infectious complications were the most common reasons and resulted in the greatest cost burden. Factors associated with 30 and 90-days in multivariable models were recipient history of chronic lung disease (hazard ratio or HR 1.78 [95%CI: 1.14, 2.76] and HR 1.68 [1.14, 2.48], respectively), median time on dialysis (HR 1.07 [95% CI: 1.01, 1.13]and HR 1.06 [95% CI: 1.01, 1.11], respectively), being transplanted preemptively (HR 1.75 [95% CI: 1.07, 2.88] and HR 1.66 [95% CI: 1.07, 2.57], respectively), and having a transplant hospitalization lasting of and more than 11 days (HR 1.52 [95% CI: 1.01, 2.27] and HR 1.65 [95% CI: 1.16, 2.34], respectively).

Discussion:

Early hospital readmission after transplantation was common and costly. Strategies to reduce the burden of early hospital readmissions are needed for all patients.

Marginal kidney transplantation: the road less traveled

PURPOSE OF REVIEW

Kidney transplantation indisputably confers a significant survival advantage and a better quality of life compared with dialysis, however, because of the increasing demand for kidney transplantation many patients continue to wait prolonged periods for kidney transplantation. The first step to alleviate the shortage is to reduce the discard rate by utilizing more marginal kidneys. This review studied the recent literature on marginal kidney transplantation.

RECENT FINDINGS

More than 60% of high-KDPI kidneys are discarded. Despite the increase in posttransplant costs, use of high KDPI transplants suggests a gain in survival years, thus making marginal kidney transplant cost effective. Furthermore, recent evidence suggests that marginal kidney transplantation shows a survival benefit compared with remaining in the waitlist and minimizes the kidney discard rate.

SUMMARY

Transplantation with marginal kidneys provides a survival benefit over dialysis or waiting for a low-KDPI kidney. As a result, clinicians should strongly consider transplantation of marginal kidneys as opposed to waiting for a better offer.