Characteristics of patients and facility of peritoneal dialysis in Korea: Results from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) Korea

BACKGROUND

Varying peritoneal dialysis (PD)-related clinical outcomes have been reported in different countries. As a participant of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS), this study investigated the characteristics of Korean PD patients, PD facilities and the incidence rates of clinical outcomes including mortality and PD-related outcomes.

METHODS

From July 2019 to December 2021, a total of 766 Korean PD patients were included for analysis. Poisson regression analysis was used to explore the incidence rates of various clinical events including mortality, modality transfer, exit site or catheter tunnel infection and peritonitis.

RESULTS

Among the 766 patients (median age 55.5 years, males 59.5%), 276 were incident and 490 were prevalent PD patients. The incidence rates of events were as follows: all-cause mortality (0.048), modality transfer (0.051), exit site or catheter tunnel infection (0.054) and peritonitis (0.136) events per person year. The most common causative organism for exit site or tunnel infection was staphylococcus species (47%) and that for peritonitis was streptococcus (28%) followed by staphylococcus (27%) species.

CONCLUSIONS

Up to now, PDOPPS Korea has recruited 766 Korean PD patients and started documentation of major PD-related outcomes which occurred during the follow-up period. The overall incidence rates of clinical outcomes in Korean PD patients were relatively favourable. There was no statistically significant difference in the incidence rates of clinical outcomes according to both facility and patient factors.

Transition between peritoneal dialysis modalities: Impact on blood pressure levels and drug prescription in a national multicentric cohort

BACKGROUND

Hypertension is a leading cause of kidney failure, affects most dialysis patients and associates with adverse outcomes. Hypertension can be difficult to control with dialysis modalities having differential effects on sodium and water removal. There are two main types of peritoneal dialysis (PD), automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD). It is unknown whether one is superior to the other in controlling blood pressure (BP). Therefore, the aim of our study was to analyse the impact of switching between these two PD modalities on BP levels in a nationally representative cohort.

METHODS

This was a cohort study of patients on PD from 122 dialysis centres in Brazil (BRAZPD II study). Clinical and laboratory data were collected monthly throughout the study duration. We selected all patients who remained on PD at least 6 months and 3 months on each modality at minimum. We compared the changes in mean systolic/diastolic blood pressures (SBP/DBP) before and after modality transition using a multilevel mixed-model where patients were at first level and their clinics at the second level.

RESULTS

We analysed data of 848 patients (814 starting on CAPD and 34 starting on APD). The SBP decreased by 4 (SD 22) mmHg when transitioning from CAPD to APD (p < 0.001) and increased by 4 (SD 21) mmHg when transitioning from APD to CAPD (p = 0.38); consistent findings were seen for DBP. There was no significant change in the number of antihypertensive drugs prescribed before and after transition.

CONCLUSIONS

Transition between PD modalities seems to directly impact on BP levels. Further studies are needed to confirm if switching to APD could be an effective treatment for uncontrolled hypertension among CAPD patients.

High volume online hemodiafiltration: a global perspective and the Brazilian experience

Online hemodiafiltration (HDF) is a rapidly growing dialysis modality worldwide. In Brazil, the number of patients with private health insurance undergoing HDF has exceeded the number of patients on peritoneal dialysis. The achievement of a high convection volume was associated with better clinical imprand patient - reported outcomes confirming the benefits of HDF. The HDFit trial provided relevant practical information on the implementation of online HDF in dialysis centers in Brazil. This article aims to disseminate technical information to improve the quality and safety of this new dialysis modality.

Dapagliflozin and Blood Pressure in Patients with Chronic Kidney Disease and Albuminuria

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors decrease blood pressure in patients with type 2 diabetes, but the consistency and magnitude of blood pressure lowering with dapagliflozin in patients with chronic kidney disease (CKD) is unknown. We conducted a prespecified analysis of the DAPA-CKD trial to investigate the effect of dapagliflozin on systolic blood pressure (SBP) in patients with CKD, with and without type 2 diabetes.

METHODS

A total of 4304 adults with baseline estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio (UACR) 200-5000 mg/g were randomized to either dapagliflozin 10 mg or placebo once daily; median follow-up was 2.4 years. The primary endpoint was a composite of sustained ≥50% eGFR decline, end-stage kidney disease, or death from a kidney or cardiovascular cause. Change in SBP was a prespecified outcome.

RESULTS

Baseline mean (SD) SBP was 137.1 mmHg (17.4). By Week 2, dapagliflozin compared to placebo reduced SBP by 3.6 mmHg (95% CI 2.8-4.4 mmHg), an effect maintained over the duration of the trial (2.9 mmHg, 2.3-3.6 mmHg). Time-averaged reductions in SBP were 3.2 mmHg (2.5-4.0 mmHg) in patients with diabetes and 2.3 mmHg (1.2-3.4 mmHg) in patients without diabetes. The time-averaged effect of dapagliflozin on diastolic blood pressure (DBP) was 1.0 mmHg (0.6-1.4 mmHg); 0.8 mmHg (0.4-1.3 mmHg) in patients with diabetes and 1.4 mmHg (0.7-2.1 mmHg) in patients without diabetes. Benefits of dapagliflozin on the primary composite and secondary endpoints were evident across the spectrum of baseline SBP and DBP.

CONCLUSION

In patients with CKD and albuminuria, randomization to dapagliflozin was associated with modest reductions in systolic and diastolic BP.

Haemoglobin trajectories in chronic kidney disease and risk of major adverse cardiovascular events

BACKGROUND

The trajectories of haemoglobin in patients with chronic kidney disease (CKD) have been poorly described. In such patients, we aimed to identify typical haemoglobin trajectory profiles and estimate their risks of major adverse cardiovascular events (MACE).

METHODS

We used 5-year longitudinal data from the CKD-REIN cohort patients with moderate to severe CKD enrolled from 40 nationally representative nephrology clinics in France. A joint latent class model was used to estimate, in different classes of haemoglobin trajectory, the competing risks of (i) MACE + defined as the first event among cardiovascular death, non-fatal myocardial infarction, stroke or hospitalization for acute heart failure, (ii) initiation of kidney replacement therapy (KRT) and (iii) non-cardiovascular death.

RESULTS

During the follow-up, we gathered 33 874 haemoglobin measurements from 3011 subjects (median, 10 per patient). We identified five distinct haemoglobin trajectory profiles. The predominant profile (n = 1885, 62.6%) showed an overall stable trajectory and low risks of events. The four other profiles had nonlinear declining trajectories: early strong decline (n = 257, 8.5%), late strong decline (n = 75, 2.5%), early moderate decline (n = 356, 11.8%) and late moderate decline (n = 438, 14.6%). The four profiles had different risks of MACE, while the risks of KRT and non-cardiovascular death consistently increased from the haemoglobin decline.

CONCLUSION

In this study, we observed that two-thirds of patients had a stable haemoglobin trajectory and low risks of adverse events. The other third had a nonlinear trajectory declining at different rates, with increased risks of events. Better attention should be paid to dynamic changes of haemoglobin in CKD.

International variations in serum PTH and calcium levels and their mortality associations in peritoneal dialysis patients: Results from PDOPPS

BACKGROUND

Mineral bone disorder (MBD) in chronic kidney disease (CKD) is associated with high symptom burden, fractures, vascular calcification, cardiovascular disease and increased morbidity and mortality. CKD-MBD studies have been limited in peritoneal dialysis (PD) patients. Here, we describe calcium and parathyroid hormone (PTH) control, related treatments and mortality associations in PD patients.

METHODS

We used data from eight countries (Australia and New Zealand (A/NZ), Canada, Japan, Thailand, South Korea, United Kingdom, United States (US)) participating in the prospective cohort Peritoneal Dialysis Outcomes and Practice Patterns Study (2014-2022) among patients receiving PD for >3 months. We analysed the association of baseline PTH and albumin-adjusted calcium (calciumAlb) with all-cause mortality using Cox regression, adjusted for potential confounders, including serum phosphorus and alkaline phosphatase.

RESULTS

Mean age ranged from 54.6 years in South Korea to 63.5 years in Japan. PTH and serum calciumAlb were measured at baseline in 12,642 and 14,244 patients, respectively. Median PTH ranged from 161 (Japan) to 363 pg/mL (US); mean calciumAlb ranged from 9.1 (South Korea, US) to 9.8 mg/dL (A/NZ). The PTH/mortality relationship was U-shaped, with the lowest risk at PTH 300-599 pg/mL. Mortality was nearly 20% higher at serum calciumAlb 9.6+ mg/dL versus 8.4-<9.6 mg/dL. MBD therapy prescriptions varied substantially across countries.

CONCLUSIONS

A large proportion of PD patients in this multi-national study have calcium and/or PTH levels in ranges associated with substantially higher mortality. These observations point to the need to substantially improve MBD management in PD to optimise patient outcomes.

LAY SUMMARY

Chronic kidney disease-mineral bone disorder (MBD) is a systemic condition, common in dialysis patients, that results in abnormalities in parathyroid hormone (PTH), calcium, phosphorus and vitamin D metabolism. A large proportion of peritoneal dialysis (PD) patients in this current multi-national study had calcium and/or PTH levels in ranges associated with substantially higher risks of death. Our observational study design limits our ability to determine whether these abnormal calcium and PTH levels cause more death due to possible confounding that was not accounted for in our analysis. However, our findings, along with other recent work showing 48-75% higher risk of death for the one-third of PD patients having high phosphorus levels (>5.5 mg/dL), should raise strong concerns for a greater focus on improving MBD management in PD patients.

Nephrologists' perspectives on communication and decision-making regarding technique survival in peritoneal dialysis: an international qualitative interview study

OBJECTIVES

Peritoneal dialysis (PD) allows patients increased autonomy and flexibility; however, both infectious and non-infectious complications may lead to technique failure, which shortens treatment longevity. Maintaining patients on PD remains a major challenge for nephrologists. This study aims to describe nephrologists' perspectives on technique survival in PD.

DESIGN

Qualitative semistructured interview study. Transcripts were thematically analysed.

SETTING AND PARTICIPANTS

30 nephrologists across 11 countries including Australia, the USA, the UK, Hong Kong, Canada, Singapore, Japan, New Zealand, Thailand, Colombia and Uruguay were interviewed from April 2017 to November 2019.

RESULTS

We identified four themes: defining patient suitability (confidence in capacity for self-management, ensuring clinical stability and expected resilience), building endurance (facilitating access to practical support, improving mental well-being, optimising quality of care and training to reduce risk of complications), establishing rapport through effective communications (managing expectations to enhance trust, individualising care and harnessing a multidisciplinary approach) and confronting fear and acknowledging barriers to haemodialysis (preventing crash landing to haemodialysis, facing concerns of losing independence and positive framing of haemodialysis).

CONCLUSION

Nephrologists reported that technique survival in PD is influenced by patients' medical circumstances, psychological motivation and positively influenced by the education and support provided by treating clinicians and families. Strategies to enhance patients' knowledge on PD and communication with patients about technique survival in PD are needed to build trust, set patient expectations of treatment and improve the process of transition off PD.

Efficacy and Safety of Dapagliflozin in Patients With Chronic Kidney Disease Across the Spectrum of Frailty

BACKGROUND

A sizeable proportion of patients with chronic kidney disease (CKD) are reported to be frail. Here we examined the safety and efficacy of dapagliflozin in patients with CKD by frailty level.

METHODS

Adults with CKD, with/without type 2 diabetes, with an estimated glomerular filtration rate (eGFR) of 25-75 mL/min/1.73 m2, and urinary albumin-to-creatinine ratio 200-5 000 mg/g were randomized to dapagliflozin (10 mg/day) or placebo. The primary endpoint was a composite of sustained ≥50% eGFR decline, end-stage kidney disease (ESKD), or death from kidney or cardiovascular (CV) causes.

RESULTS

Frailty index (FI), assessed by Rockwood cumulative deficit approach, was calculable in 4 303/4 304 (99.9%) patients: 1 162 (27.0%) in not-to-mildly frail (FI ≤0.210), 1 642 (38.2%) in moderately frail (FI 0.211-0.310), and 1 499 (34.8%) in severely frail categories (FI >0.311). Dapagliflozin reduced the risk of the primary composite endpoint across all FI categories (hazard ratios [95% confidence interval {CI}]: 0.50 [0.33-0.76], 0.62 [0.45-0.85], and 0.64 [0.49--0.83], respectively; p-interaction = 0.67). Results were similar for secondary outcomes including kidney composite outcome (sustained ≥50% eGFR decline, ESKD or death from kidney cause; p-interaction = 0.44), CV endpoint (heart failure hospitalization or CV death; p-interaction = 0.63), and all-cause mortality (p-interaction p = .42). Results were consistent when using FI as a continuous variable. Occurrence of serious adverse events was numerically lower in patients receiving dapagliflozin versus placebo in all FI categories (16.9% vs 20.1%, 26.3% vs 30.7%, and 42.9% vs 47.8%, in not-to-mildly, moderately, and severely frail categories, respectively).

CONCLUSIONS

The relative benefit of dapagliflozin for all outcomes was consistent across all frailty categories, with no difference in associated safety.

Glucose-lowering treatment pathways of individuals with chronic kidney disease and type 2 diabetes according to the Kidney Disease: Improving Global Outcomes 2012 risk classification

AIMS

To describe treatment pathways for key glucose-lowering therapies in individuals with chronic kidney disease (CKD) and type 2 diabetes (T2D) using retrospective data from DISCOVER CKD (NCT04034992).

METHODS

Data were extracted from the UK Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics data (2008-2020) and the US integrated Limited Claims and Electronic Health Records Database (LCED; 2012-2019). Eligible individuals were aged ≥18 years with CKD, identified by two consecutive estimated glomerular filtration rate (eGFR) measures (15-<75 mL/min/1.73 m2 ; 90-730 days apart; index date was the second measurement) and T2D. Chronological treatment pathways for glucose-lowering therapies prescribed on or after CKD index to end of follow-up were computed. Median time and proportion of overall follow-up time on treatment were described for each therapy by database and by eGFR and urinary albumin-to-creatinine ratio (UACR) categories.

RESULTS

Of 36,951 and 4339 eligible individuals in the CPRD and LCED, respectively, median baseline eGFR was 67.8 and 64.9 mL/min/1.73 m2 ; 64.2 and 63.9% received metformin prior to index; and median (interquartile range) time on metformin during follow-up was 917 (390-1671) and 454 (192-850) days (accounting for ~75% of follow-up time in both databases). The frequency of combination treatment increased over time. There were trends towards decreased metformin prescriptions with decreasing eGFR and increasing UACR within each eGFR category.

CONCLUSIONS

Individuals with CKD and T2D had many combinations of therapies and substantial follow-up time on therapy. These results highlight opportunities for improved CKD management.

CKD-Associated Pruritus and Clinical Outcomes in Nondialysis CKD

Rationale & Objective

Itching is a frequent symptom experienced by people with chronic kidney disease (CKD). We investigated the associations of CKD-associated pruritus (CKD-aP) with clinical outcomes.

Study Design

This was a longitudinal cohort study.

Setting & Participants

Patients from Brazil, France, and the United States enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) from 2013 to 2021, an international prospective cohort study of adults with nondialysis dependent CKD, and an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2 were included.

Exposure

CKD-aP was self-reported by response to the question: "During the past 4 weeks, to what extent were you bothered by itchy skin?"

Outcomes

The outcomes were as follows: CKD progression, kidney replacement therapy (KRT) initiation, mortality, hospitalization, cardiovascular events, infection events.

Analytical Approach

Associations with time-to-event outcomes were investigated using Cox proportional hazards models adjusted for potential confounders.

Results

There were 4,410 patients from 91 clinics with a median age of 69 years and a median eGFR at patient questionnaire completion of 29 (21-38) mL/min/1.73 m2. The proportion of patients not at all, somewhat, moderately, very much, and extremely bothered by itchy skin was 49%, 27%, 13%, 7%, and 3%, respectively. Patients with more advanced stages of CKD, older age, and greater comorbidities reported to be more likely bothered by itchy skin. Among patients at least moderately bothered, 23% were prescribed at least 1 pharmacotherapy (35% in the United States, 19% in France, 4% in Brazil), including antihistamine (10%), gabapentin (6%), topical corticosteroids (4%), pregabalin (3%), or sedating antihistamine (3%). The HR (95% CI) for patients extremely (vs not at all) bothered was 1.74 (1.11-2.73) for all-cause mortality, 1.56 (1.11-2.18) for all-cause hospitalization, and 1.84 (1.22-2.75) for cardiovascular events. As CKD-aP severity increased, patients also had higher rates of infection events (P = 0.04); CKD-aP severity was not associated with KRT initiation (P = 0.20) or CKD progression (P = 0.87).

Limitations

The limitations were 25% nonresponse rate, recall bias, and residual confounding factors.

Conclusions

These results demonstrate a strong association between severe itch and clinical outcomes, providing the nephrology community new insights into the possible adverse consequences of CKD-aP in individuals with nondialysis CKD, and warrant further exploration.

Plain-Language Summary

Chronic kidney disease-associated pruritus (CKD-aP) is a common disturbing symptom of chronic kidney disease (CKD). This article analyzes longitudinal data from the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) to describe prevalence of CKD-aP in 4,410 individuals with nondialysis CKD, and its association with clinical outcomes. We found that 51% of the surveyed population were bothered by pruritus. CKD-aP was more prevalent in those with more advanced stages of CKD, older age, and with more comorbid conditions. Compared to those not at all bothered by pruritus, those who were extremely bothered had a higher risk of all-cause mortality, hospitalizations, and cardiovascular events. Severity of CKD-aP was not associated with CKD progression or initiation of kidney replacement therapy.

Trends and perspectives for improving quality of chronic kidney disease care: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) affects over 850 million people globally, and the need to prevent its development and progression is urgent. During the past decade, new perspectives have arisen related to the quality and precision of care for CKD, owing to the development of new tools and interventions for CKD diagnosis and management. New biomarkers, imaging methods, artificial intelligence techniques, and approaches to organizing and delivering healthcare may help clinicians recognize CKD, determine its etiology, assess the dominant mechanisms at given time points, and identify patients at high risk for progression or related events. As opportunities to apply the concepts of precision medicine for CKD identification and management continue to be developed, an ongoing discussion of the potential implications for care delivery is required. The 2022 KDIGO Controversies Conference on Improving CKD Quality of Care: Trends and Perspectives examined and discussed best practices for improving the precision of CKD diagnosis and prognosis, managing the complications of CKD, enhancing the safety of care, and maximizing patient quality of life. Existing tools and interventions currently available for the diagnosis and treatment of CKD were identified, with discussion of current barriers to their implementation and strategies for improving the quality of care delivered for CKD. Key knowledge gaps and areas for research were also identified.

Conservative Kidney Management Practice Patterns and Resources in the United States: A Cross-Sectional Analysis of CKDopps (Chronic Kidney Disease Outcomes and Practice Patterns Study) Data

Rationale & Objective

Conservative kidney management (CKM) is a viable treatment option for many patients with chronic kidney disease. However, CKM practices and resources in the United States are not well described. We undertook this study to gain a better understanding of factors influencing uptake of CKM by describing: (1) characteristics of patients who choose CKM, (2) provider practice patterns relevant to CKM, and (3) CKM resources available to providers.

Study Design

Cross-sectional study.

Setting & Participants

This study is a cross-sectional analysis of data from US nephrology clinics enrolled in the chronic kidney disease Outcomes and Practice Patterns Study (CKDopps) collected between 2014 and 2020. Data for this study includes chart-abstracted characteristics of patients with an estimated glomerular filtration rate ≤30mL/min/1.73m2 (n=1018) and available information on whether a decision had been made to pursue CKM at the time of kidney failure, patient (n=407) reports of discussions about forgoing dialysis, and provider (n=26) responses about CKM delivery and available resources in their health systems.

Analytical Approach

Descriptive statistics were used to report patient demographics, clinical information, provider demographics, and clinic characteristics.

Results

Among data from 1018 patients, 68 (7%) were recorded as planning for CKM. These patients were older, had more comorbidities, and were more likely to require assistance with transfers. Of the 407 patient surveys, 18% reported a conversation about forgoing dialysis with their nephrologist. A majority of providers felt comfortable discussing CKM; however, no clinics had a dedicated clinic or protocol for CKM.

Limitations

Inconsistent survey terminology and unlinked patient and provider responses.

Conclusions

Few patients reported discussion of forgoing dialysis with their providers and even fewer anticipated a choice of CKM on reaching kidney failure. Most providers were comfortable discussing CKM, but practiced in clinics that lacked dedicated resources. Further research is needed to improve the implementation of a CKM pathway.

Plain-Language Summary

For older comorbid adults with kidney failure, conservative kidney management (CKM) can be an appropriate treatment choice. CKM is a holistic approach with treatment goals of maximizing quality of life and preventing progression of chronic kidney disease (CKD) without initiation of dialysis. We investigated US CKM practices and found that among 1018 people with CKD, only 7% were planning for CKM. Of 407 surveyed patients, 18% reported a conversation with their provider about forgoing dialysis. In contrast, most providers felt comfortable discussing CKM; however, none reported working in an environment with a dedicated CKM clinic or protocol. Our data show the need for further CKM education in the United States as well as dedicated resources for its delivery.

Utility of the Kidney Failure Risk Equation and Estimated GFR for Estimating Time to Kidney Failure in Advanced CKD

RATIONALE & OBJECTIVE

The Kidney Failure Risk Equation (KFRE) predicts the 2-year risk of kidney failure for patients with chronic kidney disease (CKD). Translating KFRE-predicted risk or estimated glomerular filtration rate (eGFR) into time to kidney failure could inform decision making for patients approaching kidney failure.

STUDY DESIGN

Retrospective cohort.

SETTING & PARTICIPANTS

CKD Outcomes and Practice Patterns Study (CKDOPPS) cohort of patients with an eGFR<60mL/min/1.73m2 from 34 US nephrology practices (2013-2021).

EXPOSURE

2-year KFRE risk or eGFR.

OUTCOME

Kidney failure defined as initiation of dialysis or kidney transplantation.

ANALYTICAL APPROACH

Accelerated failure time (Weibull) models used to estimate the median, 25th, and 75th percentile times to kidney failure starting from KFRE values of 20%, 40%, and 50%, and from eGFR values of 20, 15, and 10mL/min/1.73m2. We examined variability in time to kidney failure by age, sex, race, diabetes status, albuminuria, and blood pressure.

RESULTS

Overall, 1,641 participants were included (mean age 69±13 years; median eGFR of 28mL/min/1.73m2 [IQR 20-37mL/min/1.73 m2]). Over a median follow-up period of 19 months (IQR, 12-30 months), 268 participants developed kidney failure, and 180 died before reaching kidney failure. The median estimated time to kidney failure was widely variable across patient characteristics from an eGFR of 20mL/min/1.73m2 and was shorter for younger age, male sex, Black (versus non-Black), diabetes (vs no diabetes), higher albuminuria, and higher blood pressure. Estimated times to kidney failure were comparably less variable across these characteristics for KFRE thresholds and eGFR of 15 or 10mL/min/1.73m2.

LIMITATIONS

Inability to account for competing risks when estimating time to kidney failure.

CONCLUSIONS

Among those with eGFR<15mL/min/1.73m2 or KFRE risk>40%), both KFRE risk and eGFR showed similar relationships with time to kidney failure. Our results demonstrate that estimating time to kidney failure in advanced CKD can inform clinical decisions and patient counseling on prognosis, regardless of whether estimates are based on eGFR or the KFRE.

PLAIN-LANGUAGE SUMMARY

Clinicians often talk to patients with advanced chronic kidney disease about the level of kidney function expressed as the estimated glomerular filtration rate (eGFR) and about the risk of developing kidney failure, which can be estimated using the Kidney Failure Risk Equation (KFRE). In a cohort of patients with advanced chronic kidney disease, we examined how eGFR and KFRE risk predictions corresponded to the time patients had until reaching kidney failure. Among those with eGFR<15mL/min/1.73m2 or KFRE risk > 40%), both KFRE risk and eGFR showed similar relationships with time to kidney failure. Estimating time to kidney failure in advanced CKD using either eGFR or KFRE can inform clinical decisions and patient counseling on prognosis.

Regional Variation in Hemoglobin Distribution Among Individuals With CKD: the ISN International Network of CKD Cohorts

Introduction

Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in whom a single therapeutic range for hemoglobin is recommended. We sought to compare the distribution of hemoglobin across international nondialysis CKD populations and evaluate predictors of hemoglobin.

Methods

In this cross-sectional study, hemoglobin distribution was evaluated in each cohort overall and stratified by sex and estimated glomerular filtration rate (eGFR). Relationships between candidate predictors and hemoglobin were assessed from linear regression models in each cohort. Estimates were subsequently pooled in a random effects model.

Results

A total of 58,613 participants from 21 adult cohorts (median eGFR range of 17-49 ml/min) and 3 pediatric cohorts (median eGFR range of 26-45 ml/min) were included with broad geographic representation. Hemoglobin values varied substantially among the cohorts, overall and within eGFR categories, with particularly low mean hemoglobin observed in women from Asian and African cohorts. Across the eGFR range, women had a lower hemoglobin compared to men, even at an eGFR of 15 ml/min (mean difference 5.3 g/l, 95% confidence interval [CI] 3.7-6.9). Lower eGFR, female sex, older age, lower body mass index, and diabetic kidney disease were all independent predictors of a lower hemoglobin value; however, this only explained a minority of variance (R2 7%-44% across cohorts).

Conclusion

There are substantial regional differences in hemoglobin distribution among individuals with CKD, and the majority of variance is unexplained by demographics, eGFR, or comorbidities. These findings call for a renewed interest in improving our understanding of hemoglobin determinants in specific CKD populations.

Archetypal sustained low-efficiency daily diafiltration (SLEDD-f) for critically ill patients requiring kidney replacement therapy: towards an adequate therapy

Sustained low-efficiency dialysis is a hybrid form of kidney replacement therapy that has gained increasing popularity as an alternative to continuous forms of kidney replacement therapy in intensive care unit settings. During the COVID-19 pandemic, the shortage of continuous kidney replacement therapy equipment led to increasing usage of sustained low-efficiency dialysis as an alternative treatment for acute kidney injury. Sustained low-efficiency dialysis is an efficient method for treating hemodynamically unstable patients and is quite widely available, making it especially useful in resource-limited settings. In this review, we aim to discuss the various attributes of sustained low-efficiency dialysis and how it is comparable to continuous kidney replacement therapy in efficacy, in terms of solute kinetics and urea clearance, and the various formulae used to compare intermittent and continuous forms of kidney replacement therapy, along with hemodynamic stability. During the COVID-19 pandemic, there was increased clotting of continuous kidney replacement therapy circuits, which led to increased use of sustained low-efficiency dialysis alone or together with extra corporeal membrane oxygenation circuits. Although sustained low-efficiency dialysis can be delivered with continuous kidney replacement therapy machines, most centers use standard hemodialysis machines or batch dialysis systems. Even though antibiotic dosing differs between continuous kidney replacement therapy and sustained low-efficiency dialysis, reports of patient survival and renal recovery are similar for continuous kidney replacement therapy and sustained low-efficiency dialysis. Health care studies indicate that sustained low-efficiency dialysis has emerged as a cost-effective alternative to continuous kidney replacement therapy. Although there is considerable data to support sustained low-efficiency dialysis treatments for critically ill adult patients with acute kidney injury, there are fewer pediatric data, even so, currently available studies support the use of sustained low-efficiency dialysis for pediatric patients, particularly in resource-limited settings.

Unveiling the Clinical Benefits of High-Volume Hemodiafiltration: Optimizing the Removal of Medium-Weight Uremic Toxins and Beyond

Dialysis treatment has improved the survival of patients with kidney failure. However, the hospitalization and mortality rates remain alarmingly high, primarily due to incomplete uremic toxin elimination. High-volume hemodiafiltration (HDF) has emerged as a promising approach that significantly improves patient outcomes by effectively eliminating medium and large uremic toxins, which explains its increasing adoption, particularly in Europe and Japan. Interest in this therapy has grown following the findings of the recently published CONVINCE study, as well as the need to understand the mechanisms behind the benefits. This comprehensive review aims to enhance the scientific understanding by explaining the underlying physiological mechanisms that contribute to the positive effects of HDF in terms of short-term benefits, like hemodynamic tolerance and cardiovascular disease. Additionally, it explores the rationale behind the medium-term clinical benefits, including phosphorus removal, the modulation of inflammation and oxidative stress, anemia management, immune response modulation, nutritional effects, the mitigation of bone disorders, neuropathy relief, and amyloidosis reduction. This review also analyzes the impact of HDF on patient-reported outcomes and mortality. Considering the importance of applying personalized uremic toxin removal strategies tailored to the unique needs of each patient, high-volume HDF appears to be the most effective treatment to date for patients with renal failure. This justifies the need to prioritize its application in clinical practice, initially focusing on the groups with the greatest potential benefits and subsequently extending its use to a larger number of patients.

Enhancing healthcare quality and outcomes for peritoneal dialysis patients in Thailand: An evaluation of key performance indicators and PDOPPS cohort representativeness

AIM

To assess whether the peritoneal dialysis (PD) centres included in the Peritoneal Dialysis Outcomes and Practise Patterns Study (PDOPPS) in Thailand are representative of other PD centres in the country, based on 8 key performance indicators (KPIs 1-8).

METHODS

A retrospective analysis was conducted comparing PD-related clinical outcomes between PD centres included in the PDOPPS (the PDOPPS group) and those not included (the non-PDOPPS group) from January 2018 to December 2019. Logistic regression analysis was used to identify predictors associated with achieving the target KPIs.

RESULTS

Of 181 PD centres, 22 (12%) were included in the PDOPPS. PD centres in the PDOPPS group were larger and tended to serve more PD patients than those in the non-PDOPPS group. However, the process and outcome KPIs (KPIs 1-8) were comparable between the 2 groups. Large hospitals (≥120 beds), providing care to ≥100 PD cases and having experience for >10 years were independent predictors of achieving the peritonitis rate target of <0.5 episodes/year. Most PD centres in Thailand showed weaknesses in off-target haemoglobin levels and culture-negative peritonitis rate.

CONCLUSIONS

The PD centres included in Thai PDOPPS were found to be representative of other PD centres in Thailand in terms of clinical outcomes. Thus, Thai PDOPPS findings may apply to the broader PD population in Thailand.

Constipation and clinical outcomes in peritoneal dialysis: Results from Thailand PDOPPS

BACKGROUND

Patient-reported outcome measures (PROMs) are widely recognized as valuable predictors of clinical outcomes in peritoneal dialysis (PD). Our study aimed to explore the connections between patient-reported constipation and clinical outcomes.

METHODS

We assessed constipation in patients across 22 facilities participating in the Thailand Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) from 2014 to 2017. Constipation diagnosis utilized objective assessment tools such as the Bristol stool form scale (BSFS) and a self-reported questionnaire known as the constipation severity score (CSS). The BSFS is a 7-level scale that visually inspects feces based on texture and morphology, while the CSS measures constipation duration and severity using a 5-point Likert scale for various factors. We employed Cox proportional hazards model regression to determine the associations between constipation and clinical outcomes, including mortality, hemodialysis (HD) transfer and peritonitis.

RESULTS

Among 975 randomly selected PD patients from 22 facilities, 845 provided written informed consent, and 729 completed CSS questionnaire. Constipation was prevalent in the PD population (13%), particularly among older patients, those who were caregiver dependent, had diabetes and poorer nutritional status (indicated by lower time-averaged serum albumin, potassium, creatinine and phosphate concentrations). Twenty-seven percent of which experiencing symptoms of constipation for over a year. Notably, self-reported constipation at baseline was significantly associated with a shorter time to first peritonitis and higher rates of peritonitis and death. However, no significant association was found between constipation and HD transfer after adjusting for various factors, including age, gender, PD vintage, comorbidities, shared frailty by study sites and serum albumin.

CONCLUSION

Patient-reported constipation independently correlated with increased risks of peritonitis and all-cause mortality, though no such correlation was observed with HD transfer. These findings underscore the need for further investigation to identify effective interventions for constipation in PD patients.

The Role of Expert Opinion in Projecting Long-Term Survival Outcomes Beyond the Horizon of a Clinical Trial

INTRODUCTION

Clinical trials often have short follow-ups, and long-term outcomes such as survival must be extrapolated. Current extrapolation methods often produce a wide range of survival values. To minimize uncertainty in projections, we developed a novel method that incorporates formally elicited expert opinion in a Bayesian analysis and used it to extrapolate survival in the placebo arm of DAPA-CKD, a phase 3 trial of dapagliflozin in patients with chronic kidney disease (NCT03036150).

METHODS

A summary of mortality data from 13 studies that included DAPA-CKD-like populations and training on elicitation were provided to six experts. An elicitation survey was used to gather the experts' 10- and 20-year survival estimates for patients in the placebo arm of DAPA-CKD. These estimates were combined with DAPA-CKD mortality and general population mortality (GPM) data in a Bayesian analysis to extrapolate long-term survival using seven parametric distributions. Results were compared with those from standard frequentist approaches (with and without GPM data) that do not incorporate expert opinion.

RESULTS

The group expert-elicited estimate for 20-year survival was 31% (lower estimate, 10%; upper estimate, 40%). In the Bayesian analysis, the 20-year extrapolated survival across the seven distributions was 14.9-39.1%, a range that was 2.4- and 1.6-fold smaller than those produced by the frequentist methods (0.0-56.9% without and 0.0-39.2% with GPM data).

CONCLUSIONS

Using expert opinion in a Bayesian analysis provided a robust method for extrapolating long-term survival in the placebo arm of DAPA-CKD. The method could be applied to other populations with limited survival data.

International practice patterns of dyslipidemia management in patients with chronic kidney disease under nephrology care: is it time to review guideline recommendations?

BACKGROUND

In contrast to guidelines related to lipid therapy in other areas, 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend conducting a lipid profile upon diagnosis of chronic kidney disease (CKD) and treating all patients older than 50 years without defining a target for lipid levels. We evaluated multinational practice patterns for lipid management in patients with advanced CKD under nephrology care.

METHODS

We analyzed lipid-lowering therapy (LLT), LDL- cholesterol (LDL-C) levels, and nephrologist-specified LDL-C goal upper limits in adult patients with eGFR < 60 ml/min from nephrology clinics in Brazil, France, Germany, and the United States (2014-2019). Models were adjusted for CKD stage, country, cardiovascular risk indicators, sex, and age.

RESULTS

LLT treatment differed significantly by country, from 51% in Germany to 61% in the US and France (p = 0.002) for statin monotherapy. For ezetimibe with or without statins, the prevalence was 0.3% in Brazil to 9% in France (< 0.001). Compared with patients not taking lipid-lowering therapy, LDL-C was lower among treated patients (p < 0.0001) and differed significantly by country (p < 0.0001). At the patient level, the LDL-C levels and statin prescription did not vary significantly by CKD stage (p = 0.09 LDL-C and p = 0.24 statin use). Between 7-23% of untreated patients in each country had LDL-C ≥ 160 mg/dL. Only 7-17% of nephrologists believed that LDL-C should be < 70 mg/dL.

CONCLUSION

There is substantial variation in practice patterns regarding LLT across countries but not across CKD stages. Treated patients appear to benefit from LDL-C lowering, yet a significant proportion of hyperlipidemia patients under nephrologist care are not receiving treatment.

Proton-Pump Inhibitors and Serum Concentrations of Uremic Toxins in Patients with Chronic Kidney Disease

Use of proton-pump inhibitors (PPIs) is common in patients with chronic kidney disease (CKD). PPIs and many uremic toxins (UTs) are eliminated by the kidney's tubular organic anion transporter system. In a cross-sectional study, we sought to evaluate the association between PPI prescription and serum concentrations of various UTs. We studied a randomly selected sub-group of participants in the CKD-REIN cohort (adult patients with a confirmed diagnosis of CKD and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²) with available frozen samples collected at baseline. PPI prescription was recorded at baseline. Serum concentrations of 10 UTs were measured using a validated liquid chromatography tandem mass spectrometry technique. Multiple linear regression was performed, with the log UT concentration as the dependent variable. Of the 680 included patients (median age: 68 years; median eGFR: 32 mL/min/1.73 m²), 31% had PPI prescriptions at baseline. Patients using PPIs had higher levels of certain UTs in comparison to other patients, including total and free indoxyl sulfate (IS), total and free p-cresylsulfate, total and free p-cresylglucuronide (PCG), phenylacetylglutamine (PAG), free kynurenine, and free hippuric acid. After adjustment for baseline co-morbidities, number of co-prescribed drugs, and laboratory data, including eGFR, associations between PPI prescription and elevated serum concentrations of free and total IS, free and total PCG, and PAG remained significant. Our results indicate that PPI prescription is independently associated with serum UT retention. These findings are interesting to better understand the factors that may modulate serum UT concentration in CKD patients, however, they will need to be confirmed by longitudinal studies.

CVOT Summit 2022 Report: new cardiovascular, kidney, and glycemic outcomes

The 8th Cardiovascular Outcome Trial (CVOT) Summit on Cardiovascular, Kidney, and Glycemic Outcomes was held virtually on November 10-12, 2022. Following the tradition of previous summits, this reference congress served as a platform for in-depth discussion and exchange on recently completed outcomes trials as well as key trials important to the cardiovascular (CV) field. This year's focus was on the results of the DELIVER, EMPA-KIDNEY and SURMOUNT-1 trials and their implications for the treatment of heart failure (HF) and chronic kidney disease (CKD) with sodium-glucose cotransporter-2 (SGLT2) inhibitors and obesity with glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. A broad audience of primary care physicians, diabetologists, endocrinologists, cardiologists, and nephrologists participated online in discussions on new consensus recommendations and guideline updates on type 2 diabetes (T2D) and CKD management, overcoming clinical inertia, glycemic markers, continuous glucose monitoring (CGM), novel insulin preparations, combination therapy, and reclassification of T2D. The impact of cardiovascular outcomes on the design of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) trials, as well as the impact of real-world evidence (RWE) studies on the confirmation of CVOT outcomes and clinical trial design, were also intensively discussed. The 9th Cardiovascular Outcome Trial Summit will be held virtually on November 23-24, 2023 ( http://www.cvot.org ).

Untargeted plasma 1H NMR-based metabolomic profiling in different stages of chronic kidney disease

Chronic kidney disease (CKD) is a serious public health issue affecting thousands of people worldwide. CKD diagnosis is usually made by Estimated Glomerular Filtration Rate (eGFR) and albuminuria, which limit the knowledge of the mechanisms behind CKD progression. The aim of the present study was to identify changes in the metabolomic profile that occur as CKD advances. In this sense, 77 plasma samples from patients with CDK were evaluated by 1D and 2D Nuclear Magnetic Resonance Spectroscopy (NMR). The NMR data showed significant changes in the metabolomic profile of CKD patients and the control group. Principal component analysis (PCA) clustered CKD and control patients into three distinct groups, control, stage 1 (G1)-stage 4 (G4) and stage 5 (G5). Lactate, glucose, acetate and creatinine were responsible for discriminating the control group from all the others CKD stages. Valine, alanine, glucose, creatinine, glutamate and lactate were responsible for the clustering of G1-G4 stages. G5 was discriminated by calcium ethylenediamine tetraacetic acid, magnesium ethylenediamine tetraacetic acid, creatinine, betaine/choline/trimethylamine N-oxide (TMAO), lactate and acetate. CKD G5 plasma pool which was submitted in MetaboAnalyst 4.0 platform (MetPA) analysis and showed 13 metabolic pathways involved in CKD physiopathology. Metabolic changes associated with glycolysis and gluconeogenesis allowed discriminating between CKD and control patients. The determination of involved molecules in TMAO generation in G5 suggests an important role in this uremic toxin linked to CKD and cardiovascular diseases. The aforementioned results propose the feasibility of metabolic assessment of CKD by NMR during treatment and disease progression.

Healthcare resource utilization and related costs of patients with CKD from the United States: a report from the DISCOVER CKD retrospective cohort

Introduction

It is well established that chronic kidney disease (CKD) results in a significant burden on patients' health and health care providers. However, detailed estimates of the health care resource utilization (HCRU) of CKD are limited, particularly those which consider severity, comorbidities, and payer type. This study aimed to bridge this evidence gap by reporting contemporary HCRU and costs in patients with CKD across the US health care providers.

Methods

Cost and HCRU estimates of CKD and reduced kidney function without CKD (estimated glomerular filtration rate [eGFR]: 60-75 and urine albumin-to-creatinine ratio [UACR]: <30) were derived for US patients included in the DISCOVER CKD cohort study, using linked inpatient and outpatient data from the limited claims-EMR data set (LCED) and TriNetX database. Patients with a history of transplant or undergoing dialysis were not included. HCRU and costs were stratified by CKD severity using UACR and eGFR.

Results

Overall health care costs ranged from $26,889 (A1) to $42,139 (A3), and from $28,627 (G2) to $42,902 (G5) per patient per year (PPPY), demonstrating a considerable early disease burden which continued to increase with declining kidney function. The PPPY costs of later stage CKD were particularly notable for patients with concomitant heart failure ($50,191 [A3]) and those covered by commercial payers ($55,735 [A3]).

Conclusions

Health care costs and resource use associated with CKD and reduced kidney function pose a substantial burden across health care systems and payers, increasing in line with CKD progression. Early CKD screening, particularly of UACR, paired with proactive disease management may provide both an improvement to patient outcomes and a significant HCRU and cost saving to health care providers.

Gout Prevalence, Practice Patterns, and Associations with Outcomes in North American Dialysis Patients

INTRODUCTION

Gout occurs frequently in patients with kidney disease and can lead to a significant burden on quality of life. Gout prevalence, and its association with outcomes in hemodialysis (HD) and peritoneal dialysis (PD) populations located in North America, is unknown.

METHODS

We used data from North America cohorts of 70,297 HD patients (DOPPS, 2012-2020) and 5117 PD patients (PDOPPS, 2014-2020). We used three definitions of gout for this analysis: (1) having an active prescription for colchicine or febuxostat; (2) having an active prescription for colchicine, febuxostat, or allopurinol; or (3) having an active prescription for colchicine, febuxostat, or allopurinol, or prior diagnosis of gout. Propensity score matching was used to compare outcomes among patients with versus without gout. Outcomes included erythropoietin resistance index (ERI=erythropoiesis stimulating agent dose per week/(hemoglobin×weight)), all-cause mortality, hospitalization, and patient-reported outcomes (PROs).

RESULTS

The gout prevalence was 13% in HD and 21% in PD; it was highest among incident dialysis patients. Description of previous history of gout was rare, and identification of gout defined by colchicine (2%-3%) or febuxostat (1%) prescription was less frequent than by allopurinol (9%-12%). Both HD and PD patients with gout (versus no gout) were older, were more likely male, had higher body mass index, and had higher prevalence of cardiovascular comorbidities. About half of patients with a gout history were prescribed urate-lowering therapy. After propensity score matching, mean ERI was 3%-6% higher for gout versus non-gout patients while there was minimal evidence of association with clinical outcomes or PROs.

CONCLUSION

In a large cohort of PD and HD patients in North America, we found that gout occurs frequently and is likely under-reported. Gout was not associated with adverse clinical or PROs.

Effect of hypoxia and uremia on oxidative stress on erythrocytes from hemodialysis patients

Oxidative stress (OS) is essential in uremia-associated comorbidities, including renal anemia. Complications experienced by hemodialysis (HD) patients, such as hypoxemia and uremic toxins accumulation, induce OS and premature death of red blood cells (RBC). We aimed to characterize reactive oxygen species (ROS) production and antioxidant pathways in HD-RBC and RBC from healthy controls (CON-RBC) and evaluate the role of uremia and hypoxia in these pathways. ROS production, xanthine oxidase (XO) and superoxide dismutase (SOD) activities, glutathione (GSH), and heme oxygenase-1 (HO-1) levels were measured using flow cytometry or spectrophotometry in CON-RBC and HD-RBC (pre- and post-HD), at baseline and after 24 h incubation with uremic serum (S-HD) and/or under hypoxic conditions (5% O₂ ). Ketoprofen was used to inhibit RBC uremic toxins uptake. HD-RBC showed higher ROS levels and lower XO activity than CON-RBC, particularly post-HD. GSH levels were lower, while SOD activity and HO-1 levels of HD-RBC were higher than control. Hypoxia per se triggered ROS production in CON-RBC and HD-RBC. S-HD, on top of hypoxia, increased ROS levels. Inhibition of uremic toxins uptake attenuated ROS of CON and HD-RBC under hypoxia and uremia. CON-RBC in uremia and hypoxia showed lower GSH levels than cells in normoxia and non-uremic conditions. Redox mechanisms of HD-RBC are altered and prone to oxidation. Uremic toxins and hypoxia play a role in unbalancing these systems. Hypoxia and uremia participate in the pathogenesis of OS in HD-RBC and might induce RBC death and thus compound anemia.

Barriers to conservative care from patients' and nephrologists' perspectives: the CKD-REIN study

BACKGROUND

Conservative care is increasingly considered an alternative to kidney replacement therapy for kidney failure management, mostly among the elderly. We investigated its status and the barriers to its implementation from patients' and providers' perspectives.

METHODS

We analysed data from 1204 patients with advanced chronic kidney disease (CKD) [estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2] enrolled at 40 nationally representative nephrology clinics (2013-16) who completed a self-administered questionnaire about the information they received and their preferred treatment option, including conservative care, if their kidneys failed. Nephrologists (n = 137) also reported data about their clinics' resources and practices regarding conservative care.

RESULTS

All participating facilities reported they were routinely able to offer conservative care, but only 37% had written protocols and only 5% had a person or team primarily responsible for it. Overall, 6% of patients were estimated to use conservative care. Among nephrologists, 82% reported they were fairly or extremely comfortable discussing conservative care, but only 28% usually or always offered this option for older (>75 years) patients approaching kidney failure. They used various terminology for this care, with conservative management and non-dialysis care mentioned most often. Among patients, 5% of those >75 years reported receiving information about this option and 2% preferring it.

CONCLUSIONS

Although reported by nephrologists to be widely available and easily discussed, conservative care is only occasionally offered to older patients, most of whom report they were not informed of this option. The lack of a person or team responsible for conservative care and unclear information appear to be key barriers to its implementation.

Impact of unplanned peritoneal dialysis start on patients' outcomes-A multicenter cohort study

Background

Patients with end-stage kidney disease (ESKD) who start unplanned dialysis therapy are more likely to be treated with hemodialysis (HD) using a central venous catheter, which has been associated with a greater risk of infections and other complications, as well as with a higher long-term risk of death. Urgent-start PD is an alternative that has been suggested as an option for starting dialysis in these cases, with potentially better patient outcomes. However, the definition of urgent-start PD is not homogeneous, and no study, to our knowledge, has compared clinical outcomes among urgent start, early start, and conventional start of PD. In this study, we aimed to compare these types of initiation of dialysis therapy in terms of a composite outcome of patient survival and technique failure.

Methods

This is a retrospective, multicenter, cohort study, involving data from 122 PD clinics in Brazil. We used the following: Urgent-start groups refer to patients who initiated PD within 72 h after the PD catheter insertion; early-start groups are those starting PD from 72 h to 2 weeks after the catheter insertion; and conventional-start groups are those who used the PD catheter after 2 weeks from its insertion. We analyzed the composite endpoint of all causes of patient's mortality and technique failure (within the initial 90 days of PD therapy) using the following three different statistical models: multivariate Cox, Fine and Gay competing risk, and a multilevel model.

Results

We included 509 patients with valid data across 68 PD clinics. There were 38 primary outcomes, comprising 25 deaths and 13 technique failures, with a total follow-up time of 1,393.3 months. Urgent-start PD had no association with the composite endpoint in all three models.

Conclusion

Unplanned PD seems to be a safe and feasible option for treatment for patients with non-dialysis ESKD in urgent need of dialysis.

Aldosterone, Mineralocorticoid Receptor Activation, and CKD: A Review of Evolving Treatment Paradigms

Mineralocorticoid receptor (MR) activation is involved in propagating kidney injury, inflammation, and fibrosis and in the progression of chronic kidney disease (CKD). Multiple clinical studies have defined the efficacy of MR antagonism in attenuating progressive kidney disease, and the US Food and Drug Administration recently approved the nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone for this indication. In this review, we consider the basic science and clinical applicability of MR antagonism. Because hyperkalemia constitutes a constraint to implementing evidence-based MR blockade, we review MRA-associated hyperkalemia in the context of finerenone and discuss evolving mitigation strategies to enhance the safety and efficacy of this treatment. Although the FIDELIO-DKD and FIGARO-DKD clinical trials focused solely on patients with type 2 diabetes mellitus, we propose that MR activation and the resulting inflammation and fibrosis act as a substantive pathogenetic mediator not only in people with diabetic CKD but also in those with CKD without diabetes. We close by briefly discussing both recently initiated and future clinical trials that focus on extending the attributes of MR antagonism to a wider array of nondiabetic kidney disorders, such as patients with nonalbuminuric CKD.

A comparative post hoc analysis of finerenone and spironolactone in resistant hypertension in moderate-to-advanced chronic kidney disease

Background

Mineralocorticoid receptor antagonists (MRAs) reduce systolic blood pressure (SBP) and increase serum potassium concentration ([K⁺]). This indirect comparison investigated any differences in SBP-lowering and hyperkalemia risk between finerenone, a nonsteroidal MRA, and the steroidal MRA spironolactone ± a potassium binder.

Methods

In FIDELITY (a pooled analysis of FIDELIO-DKD and FIGARO-DKD), a subgroup of patients with treatment-resistant hypertension (TRH) and chronic kidney disease meeting eligibility criteria of the AMBER trial were identified (FIDELITY-TRH). The main outcomes were mean change in SBP, incidence of serum [K⁺] ≥5.5 mmol/L and hyperkalemia-associated treatment discontinuation. Results at ∼17 weeks were compared with 12 weeks from AMBER.

Results

In 624 FIDELITY-TRH patients and 295 AMBER patients, the least squares mean change in SBP (mmHg) from baseline was -7.1 for finerenone and -1.3 for placebo {between-group difference -5.74 [95% confidence interval (CI) -7.99 to -3.49], P < .0001} versus -11.7 for spironolactone + patiromer and -10.8 for spironolactone + placebo [between-group difference -1.0 (95% CI -4.4-2.4), P = .58]. The incidence of serum [K⁺] ≥5.5 mmol/L was 12% for finerenone and 3% for placebo versus 35% with spironolactone + patiromer and 64% with spironolactone + placebo. Treatment discontinuation due to hyperkalemia was 0.3% for finerenone and 0% for placebo versus 7% for spironolactone + patiromer and 23% for spironolactone + placebo.

Conclusions

In patients with TRH and chronic kidney disease compared with spironolactone with or without patiromer, finerenone was associated with a lower SBP reduction and lower risk of hyperkalemia and treatment discontinuation.Trial Registration: AMBER (NCT03071263), FIDELIO-DKD (NCT02540993), FIGARO-DKD (NCT02545049).

Patiromer utilization in patients with advanced chronic kidney disease under nephrology care in Germany

Background

Hyperkalemia (HK) is a frequent condition in patients with chronic kidney disease (CKD) that is associated with high morbidity and mortality. Patiromer has recently been introduced as a potassium binder. Data on patiromer use in patients with CKD in the real-world setting in Europe are lacking. We describe time to discontinuation and changes in serum potassium levels among German CKD stage 3-5 patients starting patiromer.

Methods

Duration of patiromer use was estimated by Kaplan-Meier curve, starting at patiromer initiation and censoring for death, dialysis, transplant or loss to follow-up. Serum potassium levels and renin-angiotensin-aldosterone system inhibitor (RAASi) use are described at baseline and during follow-up, restricted to patients remaining on patiromer.

Results

We identified 140 patiromer users within our analysis sample [81% CKD stage 4/5, 83% receiving RAASi, and median K+ 5.7 (5.4, 6.3) mmol/L]. Thirty percent of patiromer users had prior history of polystyrene sulfonate use. Overall, 95% of patiromer users stayed on treatment past 1 month, with 53% continuing for over a year. Mean serum potassium levels decreased after patiromer initiation and remained stable under treatment during follow-up (up to 180 days). Among these patients, 73%-82% used RAASis during the time periods before and after patiromer initiation, with no obvious trend indicating discontinuation.

Conclusion

Real-world evidence of patiromer use in Germany shows that, in line with what has been observed in clinical trials, patients on patiromer have a reduction in serum potassium when used long-term. Moreover, most patients on patiromer do not discontinue treatment prior to 1 year after initiation.

Healthcare resource utilisation and related costs of patients with CKD from the United Kingdom: a report from the DISCOVER CKD retrospective cohort

Background

Chronic kidney disease (CKD) is widely reported to decrease quality of life, increase morbidity and mortality and cause increased healthcare resource utilisation (HCRU) as the disease progresses. However, there is a relative paucity of accurate and recent estimates of HCRU in this patient population. Our aim was to address this evidence gap by reporting HCRU and related costs in patients with CKD from the UK primary and secondary care settings.

Methods

HCRU and cost estimates of CKD were derived for UK patients included in the DISCOVER CKD cohort study using clinical records from the Clinical Practice Research Datalink linked to external databases. Patients with a history of transplant or undergoing dialysis were not included. HCRU and costs were stratified by CKD severity using the urinary albumin:creatinine ratio (UACR) and estimated glomerular filtration rate.

Results

Hospitalisation rates more than tripled between low (A1) and high (A3) UACR categories and the mean annual per-patient costs ranged from £4966 (A1) to £9196 (A3) and from £4997 (G2) to £7595 (G5), demonstrating that a large healthcare burden can be attributed to a relatively small number of patients with later stage CKD, including those with kidney failure and/or albuminuria.

Conclusions

HCRU and costs associated with CKD impose a substantial burden on the healthcare system, particularly in the more advanced stages of CKD. New interventions that can delay the progression of CKD to kidney failure may not only prolong the patient’s life, but would also provide significant resource and cost savings to healthcare providers.

Clinical performance, intermediate and long-term outcomes of high-volume hemodiafiltration in patients with kidney failure

Hemodiafiltration (HDF), in which both convective and diffusion methods are combined, yields an increased overall solute clearance compared with hemodialysis (HD), specifically for medium and larger molecular weight uremic toxins. Due to uncertainty in the treatment effects, the nephrology community still perceives the implementation of HDF and the achievement of high convective volume as complex. In this article, we review practical aspects of the implementation of HDF that can effectively deliver a high-volume HDF therapy and assure clinical performance to most patients. We also present an overview of the impact of high-volume HDF (compared to HD) on a series of relevant biochemical, patient-reported, and clinical outcomes, including uremic toxin removal, phosphate, Inflammation and oxidative stress, hemodynamic stability, cardiac outcomes, nutritional effects, health-related quality of life, morbidity, and mortality.

POS1158 CHARACTERIZATION OF GOUT IN US PATIENTS UNDERGOING HEMODIALYSIS (HD) AND PERITONEAL DIALYSIS (PD)

Background

Gout is the most common inflammatory arthritis and occurs frequently in patients with renal disease often leading to a significant burden on quality of life and functional status.1,2 Despite the established connection of renal disease with gout, little has been reported on the prevalence, patient characteristics, and associations of gout with other outcomes in the US hemodialysis (HD) and peritoneal dialysis (PD) population.

Objectives

This project used a large end-stage renal disease (ESRD) focused-database, Dialysis Outcomes and Practice Patterns Study (DOPPS), to examine gout in dialysis-dependent patients.

Methods

Gout patients were identified by active prescription (Rx) of (1) colchicine, (2) febuxostat, or (3) allopurinol; or by (4) prior diagnosis of gout from US cohorts of 70,297 HD (DOPPS, 2012-2020) patients and 5117 PD (Peritoneal DOPPS, 2014-2020) patients. Outcomes of HD and PD patients with and without a history of gout were compared with propensity score matching. Outcomes included erythropoietin resistance index (ERI = ESA dose/(hemoglobin*weight), cardiovascular death, all-cause mortality/hospitalization, and baseline patient-reported outcomes (PROs).

Results

Gout prevalence was 13% in HD and 21% in PD and was highest among incident dialysis patients. Of the gout patients identified, the most-commonly used gout-related medications were allopurinol (9-12%), followed by colchicine (2-3%), and then febuxostat (1%, Figure 1). Both HD and PD patients with gout (vs. no gout) were older and more likely male. Gout HD and PD patients had higher BMI and higher prevalence of cardiovascular comorbidities than HD and PD patients without gout. After propensity score matching, mean ERI was 4% higher for gout vs. non-gout patients, while there was minimal evidence of association with clinical outcomes (mortality and hospitalization) or PROs.

Figure 1.

Gout prevalence by dialysis duration in patients undergoing HD and PD. Criteria for gout included gout diagnosis and use of a urate-lowering therapy.

HD, hemodialysis; PD, peritoneal dialysis; mo, months; Rx, prescription; yrs, years. Some patients were included in multiple gout categories.

Conclusion

Gout was common in US HD and PD patients, with a large proportion of these patients treated with drugs indicated for hyperuricemia (allopurinol and febuxostat) and gout flares (colchicine). The true prevalence of gout was likely higher than observed when considering potential under-ascertainment of gout diagnosis history in nephrology/dialysis-focused clinical settings.3 This report provides a snapshot of gout in the US dialysis population and offers opportunities to expand on research to improve awareness and care for patients with gout and ESRD.

References

[1]Singh JA, Strand V. Ann Rheum Dis. 2008;67:1310–6.

[2]Singh JA, Cleveland JD. BMC Neph 2019;20:93.

[3]Roughley M, et al. Arthritis Res Ther. 2018;20(1):243.

Disclosure of Interests

Angelo Karaboyas Grant/research support from: Horizon Therapeutics, Junhui Zhao Grant/research support from: Horizon Therapeutics, Brian LaMoreaux Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Brad Marder Shareholder of: Horizon Therapeutics, Employee of: Horizon Therapeutics, Barry Gorlitsky Consultant of: AstraZenica, Davita, Horizon Therapeutics, Jensen Pharmaceuticals, KidneyAide LLC, vinicius domingues Consultant of: Abbvie, Aurinia Pharma, Exagen, Eli Lilly, Roberto Pecoits-Filho Grant/research support from: Horizon Therapeutics, Bruce Robinson Grant/research support from: Horizon Therapeutics

MO653: High-Flux Haemodialysis and Haemodiafiltration: A Comparative Study Based on 1-H NMR Serum Metabolic Profile

BACKGROUND AND AIMS

Patients with chronic kidney disease (CKD) accumulate uraemic toxins (UTs). When compared to other conventional dialysis modalities, high volume haemodiafiltration (HDF) improves the removal of medium and low molecular weight UTs. The present study is a post-hoc analysis comparing the metabolomic profile in serum from patients under high flux HD (hf-HD) and HDF in HDFIT, a multicentric randomized controlled trial (RCT).

METHOD

Random (pre- and post-dialysis) samples from nine patients in a study arm were selected at baseline and at the end of the follow-up. To compare the samples, 26 possibly matching metabolites were identified by a t-test among the four groups using 1-H nuclear magnetic resonance (NMR).

To evaluate the comparison between the modalities in a single treatment session, the clearance rates (CRs) of each metabolite were calculated based on pre- and post-dialysis samples. In addition, to evaluate the effect of UTs removal during the trial follow-up period, the pre-dialysis metabolite concentrations both at the baseline and 6 months were compared with the two arms of the study.

RESULTS

Evaluating the concentrations of the metabolites during the follow-up period for each study arm, it was possible to assess the effects of UTs removal during the study for each modality. The comparison of the intensity of the peaks identified 26 possible metabolites that differentiated hf-HD and HDF in this timeframe. The correlation (see Figure 1a) then suggested that the peak integrals of 16 of these metabolites increased from baseline to 6 months in the hf-HD, but not in the HDF arm. Amongst the metabolites, several are involved in important metabolic pathways, such as the metabolisms of phenylalanine and the biosynthesis of phenylalanine, tyrosine and tryptophan, which both relate to UTs and the development of cardiovascular diseases. The peak integration relative to glycolic acid was significantly higher (P&lt;.05) at 6 months than at baseline (see Figure 1b) in the hf-HD than in the HDF arm, which has been related to an increased number of renal failure and of renal insufficiency cases [1,2], as well as it related to liver damage [3].

CONCLUSION

The concentrations of metabolites related both to CKD and associated pathologies were stable in the HDF arm only during the follow-up period, suggesting enhancement of the long-term stability by this method. In the hf-HD long-term follow-up, the relative increase in the glycolic acid peak integration area, which is related to the metabolite concentration, has also previously been linked to an increased number of renal failures and renal insufficiency cases and to liver damages.

Diabetes Prevalence, Treatment, Control, and Outcomes Among Hemodialysis Patients in the Gulf Cooperation Council Countries

INTRODUCTION

Diabetes mellitus (DM) is a leading cause of end-stage kidney disease (ESKD). We provide the first description of DM prevalence, related outcomes, and the hemoglobin A1c (HbA1c)/mortality relationship in national hemodialysis (HD) patient samples across the Gulf Cooperation Council (GCC) countries.

METHODS

We analyzed data from the prospective Dialysis Outcomes and Practice Patterns Study (DOPPS) in the GCC (2012-2018, N = 2274 HD patients ≥18 years old). Descriptive statistics were calculated, and all-cause mortality was analyzed for patients with DM versus without DM and by HbA1c levels in patients with DM by Cox regression with progressive confounder adjustments.

RESULTS

DM in the GCC ranged from 45% to 74% in patients with HD by country. Patients with DM were 13 years older (59.9 vs. 46.7 years) and had greater body mass index (BMI), shorter median years on dialysis (1.5 vs. 3.0 years), and higher comorbidity burden. In patients with DM, insulin use was 26% to 50% across countries, with variable oral antidiabetic drug use (2%-32%); median HbA1c levels were 6.1% to 7.5% across countries. Patients with DM (vs. without DM) had higher crude death rates (15.6 vs. 6.2 deaths per 100 patient-years, mean follow-up 1.3 years) and adjusted mortality (hazard ratio [HR] = 1.72 [95% CI 1.23-2.39]). In patients with DM, mortality was lowest at HbA1c 6.5% to 7.5%, with mortality particularly elevated at high HbA1c >9% (HR = 2.13 [95% CI 1.10-4.10]).

CONCLUSION

Patients with DM in the GCC have high comorbidity burden and mortality rates despite a relatively young mean age. In GCC countries, a holistic strategy for improving diabetes care and outcomes for HD patients is needed at the primary, secondary, and tertiary levels.

Kidney outcomes with finerenone: an analysis from the FIGARO-DKD study

BACKGROUND

In FIGARO-DKD, finerenone reduced the risk of cardiovascular events in patients with type 2 diabetes (T2D) and stage 1-4 chronic kidney disease (CKD). In FIDELIO-DKD, finerenone improved kidney and cardiovascular outcomes in patients with advanced CKD. This analysis further explores kidney outcomes in FIGARO-DKD.

METHODS

FIGARO-DKD (NCT02545049) included patients with urine albumin-to-creatinine ratio (UACR) 30-<300 mg/g and estimated glomerular filtration rate (eGFR) 25-90 mL/min/1.73 m2 or UACR 300-5000 mg/g and eGFR ≥60 mL/min/1.73 m2. Outcomes included two composite kidney endpoints, a composite of ≥40% decrease in eGFR from baseline sustained over ≥4 weeks, kidney failure or renal death, and a composite of ≥57% decrease in eGFR from baseline sustained over ≥4 weeks, kidney failure or renal death. Changes in albuminuria and eGFR slope were also analyzed. Kidney and CV outcomes were evaluated by baseline UACR.

RESULTS

A lower incidence rate for the eGFR ≥40% kidney composite endpoint was observed with finerenone compared with placebo, but the between-group difference was not significant [hazard ratio (HR) = 0.87; 95% confidence interval (CI): 0.76-1.01; P = .069]. A greater treatment effect was observed on the eGFR ≥57% kidney composite endpoint (HR = 0.77; 95% CI: 0.60-0.99; P = 0.041) with a 36% relative risk reduction for end-stage kidney disease. A larger magnitude of effect on kidney outcomes was observed with finerenone versus placebo for patients with severely increased albuminuria than with moderately increased albuminuria. Improvements in UACR, eGFR slope and cardiovascular risk were evident in both subgroups with finerenone.

CONCLUSIONS

The present analyses suggest that finerenone protects against kidney disease progression and cardiovascular events in patients with T2D and early- or late-stage CKD.

Early Identification of Chronic Kidney Disease – A Scoping Review of the Global Populations

Introduction

Decisions on whether to screen for chronic kidney disease (CKD) or not remain contentious in nephrology. This study provides a global overview of early CKD identification efforts.

Methods

Guidelines for scoping reviews were followed and studies were identified by searching MEDLINE, EMBASE, Cochrane Library, CINAHL, ISI Web of Science, and PsycINFO. Data extracted from included studies focused on the following 4 themes: study population, measurement methods, interventions used, and available policies.

Results

We identified 290 CKD screening and detection programs from 83 countries. Overall sample size was 3.72 million (North East Asia: 1.19 million), detection of CKD was the aim in 97.6%, 63.1% used population-based screening methods, and only 12.4% were in rural populations. Reported CKD prevalence (stages 3–5) was higher in targeted- (14.8%) than population-based studies (8.0%). Number of persons needed to screen (NNS) to identify 1 case was also lower in targeted studies (7 vs. 13). Single measurements (80%) and the combination of estimation of glomerular filtration rate with a urine test (albuminuria/proteinuria) (71.4%) were frequently used to detect CKD. Only 2.8% of studies included an intervention such as pharmacotherapy in identified cases. Policies on early identification were available in 30.1% of countries included.

Conclusion

Methods for early CKD identification vary worldwide, often leading to wide variations in the reported prevalence. Efforts to standardize measurement methods for early detection focusing on high-risk populations and ensuring appropriate interventions are available to those identified with CKD will improve the value of programs and improve patient outcomes.

High-volume hemodiafiltration decreases the pre-dialysis concentrations of indoxyl sulfate and p-cresyl sulfate compared to hemodialysis: a post-hoc analysis from the HDFit randomized controlled trial

BACKGROUND

Although high-volume online hemodiafiltration has been associated with higher clearance and lower pre-dialysis concentration of middle molecular weight toxins compared to hemodialysis, its effect on protein-bound uremic toxins has shown inconclusive results. In this study, we investigated whether hemodiafiltration impacts pre-dialysis plasma levels of the toxins indoxyl sulfate, p-cresyl sulfate, and indole-3-acetic acid compared to high-flux hemodialysis.

METHODS

This is a post-hoc analysis of the multicenter, randomized controlled trial HDFit (ClinicalTrials.gov: NCT02787161). Uremic toxins were determined by high performance liquid chromatography at baseline, 3, and 6 months. Mean differences in monthly changes of pre-dialysis uremic toxin concentrations between hemodiafiltration and high-flux hemodialysis were analyzed using linear mixed-effect models.

RESULTS

One hundred ninety-three patients (mean age 53 years old, 71% males) were analyzed. There were no differences between groups regarding clinical and biochemical characteristics at baseline or duration of dialysis session and blood flows throughout the follow-up. Mean differences in rates of change (μM/month, [confidence interval CI]) in high-flux hemodialysis vs. hemodiafiltration were 2.4 [0.3 to 4.56], 3.94 [- 1.54 to 9.41] and 0.06 [- 0.6 to 0.5] for indoxyl sulfate, p-cresyl sulfate and indole-3-acetic acid, respectively. In the exploratory analysis, these differences in high-flux hemodialysis vs. hemodiafiltration subgroup with convective volume > 27.5 L were 2.86 [0.43 to 5.28], 7.43 [0.7 to 14.16] and - 0.19 [- 0.88 to 0.50].

CONCLUSION

These exploratory findings suggest that hemodiafiltration is more effective in reducing indoxyl sulfate as compared to standard high-flux hemodialysis, and also that this effect was extended to p-cresyl sulfate in patients achieving higher convective volumes.

Cost of End-of-Life Inpatient Encounters in Patients with Chronic Kidney Disease in the United States: A Report from the DISCOVER CKD Retrospective Cohort

Introduction

Real-world data reporting healthcare resource utilisation and costs associated with end-of-life care for patients with chronic kidney disease (CKD) are limited. We examined length of hospitalisation and costs associated with end-of-life inpatient encounters using retrospective data from DISCOVER CKD.

Methods

Data on inpatient encounters for patients with CKD aged ≥ 18 years between January 2016 and March 2020 were extracted from the US Premier Hospital Database. Encounters ending in death were identified and grouped by reason for the encounter, using the International Classification of Diseases, Tenth Revision, and by their insurance coverage. Encounters were evaluated overall and stratified according to cardiovascular (CV), kidney failure and infection-related reasons, and by their coverage by commercial, Medicaid, Medicare or other insurers. Length of hospitalisation and total costs were calculated for encounters.

Results

Among 237,734 encounters ending in death, the mean [standard deviation (SD)] age was 74.2 (12.4) years, and 45.3% of patients were female. In total, 25,118, 4210 and 76,307 encounters were classified as relating to CV reasons, kidney failure and infection, respectively. Among all encounters, the mean (SD) length of hospitalisation ranged from 9.1 (11.2) (Medicare) to 12.8 (18.4) (Medicaid) days. Across insurers, encounters related to kidney failure were associated with the longest hospitalisations compared with CV and infection [mean range (days): 10.7–15.9 vs. 7.5–10.5 and 8.7–12.7, respectively]. The median [interquartile range (IQR)] total cost of any inpatient encounter was $17,057 ($8040–35,873). Kidney failure-related encounters had higher costs compared with CV and infection [median (IQR), $18,469 ($8673–38,315) vs. $17,503 ($7766–39,693) and $16,403 ($7762–34,910), respectively]. Medicaid-covered encounters had the highest costs of all insurers [median (IQR), $16,189 ($7725–33,443)].

Conclusions

Among patients with CKD, end-of-life encounters were most frequently related to infection. Encounters relating to kidney failure incurred the highest costs.

Trial registration

ClinicalTrials.gov identifier: NCT04034992.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-02010-3.