Impact of patient characteristics and comorbidity profile on activation of patients on the kidney transplantation waiting list

Cardiovascular disease in waitlisted hemodialyzed patients

BACKGROUND

Cardiovascular diseases are one of the major limitations in the evaluation of potential kidney transplantation. The study aimed to assess cardiovascular status, including cardiovascular risk factors in waitlisted hemodialyzed patients.

MATERIAL AND METHODS

From the population of 5,068 hemodialyzed patients (60% men), we included 449 waitlisted and 4,619 not considered for potential kidney transplantation. We assessed demographic data, basal biochemical data, and cardiovascular disease prevalence.

RESULTS

Waitlisted patients (262 males) were significantly younger when compared to non-listed patients (2,718 males); 53.2 ± 14.2 vs. 67.2 ± 3.3 years (p < 0.001), had lower Charlson comorbidity score (3.33 ± 1.52 vs. 4.42 ± 1.93, p < 0.001), lower BMI (26.3±.5.07 vs. 27.7 ± 6.15 kg/m2, p < 0.001), with lower prevalence of cardiovascular disease (46.5% vs. 66.8%, p < 0.001), diabetes (20.5% vs. 37,8%, p < 0.001). The prevalence of hypertension was similar in both groups (94.7% vs. 92.7%, NS). Blood pressure was significantly higher in waitlisted patients relative to non-waitlisted (143 ± 16 mmHg vs. 140 ± 17 mm Hg, p < 0.001 for systolic blood pressure and 80 ± 9 mmHg vs. 75 ± 9 mmHg, p < 0.001 for diastolic blood pressure). Ultrafiltration was also higher in waitlisted population over non-waitlisted (31.3 ± 12.7 mL/kg per HD session vs. 28.4 ± 12.6 mL/kg per HD session, p < 0.001). Mean dialysis vintage, the mean number of hypotensive medications (mean 2.5), the prevalence of apparent treatment-resistant hypertension, and eKt/V were similar, as well as sex distribution.

CONCLUSION

Waitlisted patients are a much healthier population, with fewer comorbidities but blood pressure control not meeting target ranges for the present guidelines. The low number of hypotensive medications should be reassessed and the treatment of hypertension may require further attention.

Identifying when racial and ethnic disparities arise along the continuum of transplant care: a national registry study

Background

Fewer minoritized patients with end-stage kidney disease (ESKD) receive kidney transplantation (KT); efforts to mitigate disparities have thus far failed. Pinpointing the specific stage(s) within the transplant care continuum (being informed of KT options, joining the waiting list, to receiving KT) where disparities emerge among each minoritized population is pivotal for achieving equity. We therefore quantified racial and ethnic disparities across the KT care continuum.

Methods

We conducted a retrospective cohort study (2015-2020), with follow-up through 12/10/2021. Patients with incident dialysis were identified using the US national registry data. The exposure was race and ethnicity (Asian, Black, Hispanic, and White). We used adjusted modified Poisson regression to quantify the adjusted prevalence ratio (aPR) of being informed of KT, and cause-specific hazards models to calculate adjusted hazard ratios (aHR) of listing, and transplantation after listing.

Findings

Among 637,951 adults initiating dialysis, the mean age (SD) was 63.8 (14.6), 41.8% were female, 5.4% were Asian, 26.3% were Black, 16.6% were Hispanic, and 51.7% were White (median follow-up in years [IQR]:1.92 [0.97-3.39]). Black and Hispanic patients were modestly more likely to be informed of KT (Black: aPR = 1.02, 95% confidence interval [CI]:1.01-1.02; Hispanic: aPR = 1.03, 95% CI: 1.02-1.03) relative to White patients. Asian patients were more likely to be listed (aHR = 1.18, 95% CI: 1.15-1.21) but less likely to receive KT (aHR = 0.56, 95% CI: 0.54-0.58). Both Black and Hispanic patients were less likely to be listed (Black: aHR = 0.87, 95% CI: 0.85-0.88; Hispanic: aHR = 0.85, 95% CI: 0.85-0.88) and receive KT (Black: aHR = 0.61, 95% CI: 0.60-0.63; Hispanic: aHR = 0.64, 95% CI: 0.63-0.66).

Interpretation

Improved characterization of the barriers in KT access specific to each racial and ethnic group, and the interventions to address these distinct challenges throughout the KT care continuum are needed; our findings identify specific stages most in need of mitigation.

Funding

National Institutes of Health.

Impact of type 2 diabetes mellitus on kidney transplant rates and clinical outcomes among waitlisted candidates in a single center European experience

Despite type 2 diabetes mellitus (T2D) is commonly considered a detrimental factor in dialysis, its clear effect on morbidity and mortality on waitlisted patients for kidney transplant (KT) has never been completely elucidated. We performed a retrospective analysis on 714 patients admitted to wait-list (WL) for their first kidney transplant from 2005 to 2010. Clinical characteristics at registration in WL (age, body mass index -BMI-, duration and modality of dialysis, underlying nephropathy, coronary artery -CAD- and/or peripheral vascular disease), mortality rates, and effective time on WL were investigated and compared according to T2D status (presence/absence). Data about therapy and management of T2D were also considered. At the time of WL registration T2D patients (n = 86) were older than non-T2D (n = 628) (58.7 ± 8.6 years vs 51.3 ± 12.9) with higher BMI (26.2 ± 3.8 kg/m² vs 23.8 ± 3.6), more frequent history of CAD (33.3% vs 9.8%) and peripheral vascular disease (25.3% vs 5.8%) (p < 0.001 for all analyses). Considering overall population, T2D patients had reduced survival vs non-T2D (p < 0.001). Transplanted patients showed better survival in both T2D and non-T2D groups despite transplant rate are lower in T2D (75.6% vs 85.8%, p < 0.001). T2D was also associated to similar waiting time but longer periods between dialysis start and registration in WL (1.6 years vs 1.2, p = 0.008), comorbidity-related suspension from WL (571 days vs 257, p = 0.002), and increased mortality rate (33.7% vs 13.9% in the overall population, p < 0.001). In T2D patients admitted to WL, an history of vascular disease was significantly associated to low patient survival (p = 0.019). In conclusion, T2D significantly affects survival also on waitlisted patients. Allocation policies in T2D patients may be adjusted according to increased risk of mortality and WL suspension due to comorbidities.

Renal Replacement Knowledge and Preferences for African Americans With Chronic Kidney Disease

BACKGROUND

Renal replacement therapies (RRT) other than in-centre haemodialyses are underutilised by African Americans with end-stage renal disease (ESRD) even though they are associated with reduced costs, morbidity and mortality as well as improved quality of life for patients.

OBJECTIVES

To understand African American patients' knowledge of RRT options and how patient, provider and system-factors contribute to knowledge and preferences. Participants' interviews were conducted at the University of Chicago Medical Center with African American patients with chronic kidney disease (CKD). The final analysis included 28 interviews; 22 patients had CKD not yet on dialysis or having received a transplant, while 6 had reached ESRD and were receiving treatment for kidney failure. Approach Transcripts were uploaded into NVivo8 for coding. Thematic analysis was used for data interpretation.

RESULTS

Four themes were identified: (1) limited knowledge of home modalities and deceased donor options, (2) CKD patients gave little thought to choosing RRT options, (3) CKD patients relied on doctors for treatment decisions, and (4) while patients reported knowledge of living kidney donation transplants (LKDT), it did not translate to receiving an LKDT.

CONCLUSION

African Americans face significant knowledge and access barriers when deciding on their RRT treatment. Even patients with advanced CKD were still in the early stages of RRT selection. Understanding the knowledge gaps and barriers patients face will inform our subsequent intervention to educate and motivate patients to increase CKD self-care and improve communication between patients, their families and their providers about different RRT treatments.

High Cardiovascular Risk Profile in Young Patients on the Kidney Transplant Waiting List

BACKGROUND

Cardiovascular complications are the leading causes of morbidity and mortality in patients with end-stage renal disease. The risk profile very often contributes to their death while on the waiting list. Most studies have been carried out in older patients with end-stage renal disease, reflecting the general dialysis population. The aim of this study was to analyze the risk profile in young patients with advanced chronic kidney disease on the kidney transplant waiting list.

METHODS

This was a retrospective, single-center study of 748 patients on the kidney transplant waiting list at the University Hospital Essen, Germany. Clinical and laboratory parameters were collected between 2015 and 2016.

RESULTS

Of 748 patients (62% male), the median age was 48 years. Hypertension, coronary heart disease, and diabetes mellitus were the leading comorbidities, and their frequency rose significantly with age. Their median laboratory values did not differ significantly depending on age except for albumin. Hyperuricemia was quite common in our population with a prevalence of about 75% in women and 50% in men throughout all age groups. A total of 26.6% of the patients between 18 and 35 years of age had advanced anemia (hemoglobin < 10 g/dL), and thus they were affected most frequently. Elevated C-reactive protein serum levels were observed in 37.2% of the patients. Regarding the lipid profile, we observed that HDL cholesterol was within the normal range in only among 51.9% of men and 44.3% of women.

CONCLUSIONS

Cardiovascular risk factors are quite common in our cohort and affect young patients similarly.

Inequalities and outcomes: end stage kidney disease in ethnic minorities

Background

The international evidence about outcomes of End Stage Kidney Disease (ESKD) for ethnic minorities was reviewed to identify gaps and make recommendations for researchers and policy makers.

Methods

Nine databases were searched systematically with 112 studies from 14 different countries included and analysed to produce a thematic map of the literature.

Results

Reviews (n = 26) highlighted different mortality rates and specific causes between ethnic groups and by stage of kidney disease associated with individual, genetic, social and environmental factors. Primary studies focussing on uptake of treatment modalities (n = 19) found ethnic differences in access. Research evaluating intermediate outcomes and quality of care in different treatment phases (n = 35) e.g. dialysis adequacy, transplant evaluation and immunosuppression showed ethnic minorities were disadvantaged. This is despite a survival paradox for some ethnic minorities on dialysis seen in studies of longer term outcomes (n = 29) e.g. in survival time post-transplant and mortality. There were few studies which focussed on end of life care (n = 3) and ethnicity.

Gaps identified were: limited evidence from all stages of the ESKD pathway, particularly end of life care; a lack of system oriented studies with a reliance on national routine datasets which are limited in scope; a dearth of qualitative studies; and a lack studies from many countries with limited cross country comparison and learning.

Conclusions

Differences between ethnic groups occur at various points and in a variety of outcomes throughout the kidney care system. The combination of individual factors and system related variables affect ethnic groups differently indicating a need for culturally intelligent policy informed by research to prevent disadvantage.

Outcomes of end-stage renal disease patients on the waiting list for deceased donor kidney transplantation: A single-center study

Background

Kidney transplantation is an effective renal replacement therapy for patients with end-stage renal disease (ESRD). In this study, we assessed the impact of the baseline characteristics and comorbidities of ESRD patients on the probability of deceased donor kidney transplantation (DDKT) and evaluated the morbidity and mortality during the time spent waiting.

Methods

The study population consisted of 544 ESRD patients on the waiting list for DDKT at Chungnam National University Hospital in South Korea between February 2000 and October 2015. The patients were observed from the date of transplantation list registration to the date of transplantation. Baseline characteristics and comorbidities were investigated together with new-onset comorbidities that occurred during the waiting time.

Results

Diabetes mellitus (39.0%), hypertension (25.2%), and glomerulonephritis (21.3%) were the three most common causes of ESRD in this study, and coronary artery disease (9.4%) was the most common comorbidity. The 115 patients (19.3%) who underwent DDKT had a mean waiting time of 1,711 days (768–2,654 days or 4.68 years [2.10–7.27]). Blood groups other than type O, peritoneal dialysis, and nondiabetic ESRD were significantly associated with a higher likelihood of DDKT. Infection was the leading cause of death and the most common comorbidity that arose during the waiting time. Patients who experienced cardiovascular events during the waiting time showed a lower transplant rate compared with those who did not.

Conclusion

The prevalence of comorbidities was high in renal transplantation candidates. During the often-long waiting time, new comorbidities may occur, with long-term sequelae limiting access to kidney transplantation or resulting in death.

Peripheral Vascular Disease and Death in Southern European Kidney Transplant Candidates: A Competing Risk Modeling Approach

BACKGROUND

The association between peripheral vascular disease (PVD) and survival among kidney transplant (KT) candidates is uncertain.

METHODS

We assessed 3851 adult KT candidates from the Andalusian Registry between 1984 and 2012. Whereas 1975 patients received a KT and were censored, 1876 were on the waiting list at any time. Overall median waitlist time was 21.2 months (interquartile range, 11-37.4). We assessed the association between PVD and mortality in waitlisted patients using a multivariate Cox regression model, with a competing risk approach as a sensitivity analysis.

RESULTS

Peripheral vascular disease existed in 308 KT candidates at waitlist entry. The prevalence of PVD among nondiabetic and diabetic patients was 4.5% and 25.3% (P < 0.0001). All-cause mortality was higher in candidates with PVD (45% vs 21%; P < 0.0001). Among patients on the waiting list (n = 1876) who died (n = 446; 24%), 272 (61%) died within 2 years after listing. Cumulative incidence of all-cause mortality at 2 years in patients with and without PVD was 23% and 6.4%, respectively (P < 0.0001); similar differences were observed in patients with and without diabetes. By competing risk models, PVD was associated with a 1.9-fold increased risk of mortality (95% confidence interval [95% CI], 1.4-2.5). This association was stronger in waitlisted patients without cardiac disease (subhazard ratio, 2.2; 95% CI, 1.6-3.1) versus those with cardiac disorders (subhazard ratio, 1.5; 95% CI, 0.9-2.5). No other significant interactions were observed. Similar results were seen after excluding diabetics.

CONCLUSIONS

Peripheral vascular disease is a strong predictor of mortality in KT candidates. Identification of PVD at list entry may contribute to optimize targeted therapeutic interventions and help prioritize high-risk KT candidates.

Survey of Canadian Kidney Transplant Specialists on the Management of Morbid Obesity and the Transplant Waiting List

Background:

Obesity is associated with increased surgical complications and long-term cardiovascular mortality. Studies of access in kidney transplantation have found a bias against obese patients on the wait-listing.

Objective:

To determine the current state of clinical practice for the management of obesity in kidney transplantation.

Design:

A survey in two versions, PDF and traditional paper, composed of categorical questions.

Setting:

A pan-Canadian survey of transplant nephrologists and surgeons.

Methods:

The survey PDF was distributed electronically to the Kidney Group of the Canadian Society of Transplantation. A shorter, hardcopy version was distributed subsequently at a national transplant meeting.

Results:

There were 47 responses, including almost every Canadian adult transplant program. Most (81%) reported the use of a body mass index limit for access to the waiting list. However, only 40% reported a strict enforcement. There were several instances of intra-hospital disagreements regarding the use of a policy, among the centers with multiple responses. The body mass index limit was most commonly 40 kg/m² (62%), followed by 35 kg/m² (36%). Despite the body mass index limit, few centers (30%) reported having a weight management program. The reported experience with bariatric surgery was small, though nearly all replied that they would refer to a bariatric specialist in the future.

Limitations:

This national survey provides a broad assessment of clinical practice. The distinction between an official policy and informal clinical tendencies is difficult. The results cannot be used to support any specific limit or policy.

Conclusions:

This survey found that the body mass index limit for access to the kidney transplant waiting list was common in Canada. Several inconsistencies suggest a lack of official policy. To achieve equity in access, clear guidelines for obesity should be established and enforced. Bariatric surgery has the promise of rapid weight loss. Resource allocation to study obesity in transplant patients will be essential.

Transplanting the elderly: Balancing aging with histocompatibility

Across the world, the proportions of senior citizens (i.e. those ≥65years) increase rapidly and are predicted to constitute over 25% of the general population by 2050. In 2012 already 48% of the population with end stage renal disease (ESRD) was aged 65years or older. Transplantation is considered the preferred treatment option for ESRD offering survival advantage over long-term dialysis in the majority of patients. Indeed, acceptable outcomes have been documented for selected patients over the age of 70years or even cases over 80years. The reality of organ scarcity and prolonged waiting times for a deceased donor kidney transplantation, however, indicate that at best 50% of the selected elderly may have realistic expectations to receive a timely transplant offer. By choice or medical selection, access to transplantation also decreases with increasing age. In order to expedite the chance for elderly to receive a kidney transplant dedicated allocation systems have been developed. These allocation systems, like the Eurotransplant Senior Program (ESP), support preferential local allocation of kidneys from older donors to older patients in order to match recipient and graft life while disregarding histocompatibility for HLA antigens. The consequence has been more acute rejection episodes and an increase in immunosuppressive load. In the elderly, the most common cause of graft loss is death with functioning graft and death from infectious diseases is one of the dominant causes. The Eurotransplant Senior DR-compatible Program (ESDP) was designed to further improve the perspective of successful transplantation in the elderly in terms of life and quality of life by re-introducing matching criteria for HLA-DR in the old-for-old algorithm.