Dialysis Outcomes and Practice Patterns Study (DOPPS): its strengths, limitations, and role in informing practices and policies

Atherosclerotic Diseases in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have a high incidence of atherosclerotic diseases, such as ischemic heart disease, cerebrovascular disease, and peripheral arterial disease. To prevent the incidence of atherosclerotic cardiovascular disease in patients with CKD, the pathology of arteriosclerosis should be determined. Vascular calcification is a characteristic of arteriosclerosis in patients with CKD. Recent studies have reported that coronary artery calcification is associated with acute coronary syndromes. CKD is frequently associated with heart failure. Furthermore, recent evidence suggests that coronary artery calcification affects asymptomatic myocardial ischemia. Hyperphosphatemia and calciprotein particles may be involved in the pathology of vascular calcification. Controlling the progression of vascular calcification and classical atherosclerotic risk factors is important to prevent the occurrence of atherosclerotic diseases in CKD.

Thromboembolic Events in the Hemodialysis Setting: Understanding Risk Profiles and Cumulative Incidences to Inform Clinical Trial Design

BACKGROUND

People with kidney failure have a high risk of cardiovascular morbidity/death, including thromboembolic events. Factor XIa inhibitors are a new class of anticoagulants in development that may offer antithrombotic benefits with a lower risk of incremental bleeding events than traditional therapies. We investigated major adverse vascular events (MAVEs), a relevant composite outcome for testing novel antithrombotic agents, in a large cohort of patients on hemodialysis, to better understand the key requirements to adequately design a phase 3 trial.

METHODS AND RESULTS

We included 25 211 patients on hemodialysis for >90 days in phases 4 to 7 (2009-2021) of the DOPPS (Dialysis Outcomes and Practice Patterns Study). Atherosclerotic cardiovascular disease (ASCVD) was defined as history/presence of coronary, peripheral, or cerebrovascular disease. We estimated MAVE rates and cumulative incidence, overall and by ASCVD. Over half (52%) of the cohort met the ASCVD criteria. The MAVE hospitalization/death composite rate (per 100 patient-years) was 6.0 in the overall cohort and 8.7 in the ASCVD subset. Three-year cumulative incidence of MAVE was 13% in the overall cohort and 18% in the ASCVD subset. The estimated sample size to be randomized in a hypothetical trial in the ASCVD population was ≈7000 patients.

CONCLUSIONS

Even in the enriched ASCVD group, the observed MAVE incidence combined with a high competing risk, regulatory requirements (α=0.01), and limited recruitment pool makes feasibility of a potential randomized trial targeting MAVE reduction challenging. These results highlight key considerations and challenges for developers of novel therapies targeting systemic thromboembolic events in patients on hemodialysis.

Global hemodialysis vascular access care: Three decades of evolution

The development of vascular access for hemodialysis has come a long way since 1943 when the first hemodialysis treatment was performed in humans by connecting an artery and vein using an external glass canula. Since then, vascular access care has evolved robustly through contributions from numerous countries and professional nephrology societies, worldwide. To understand the global distribution and contribution of different specialties to medical literature on dialysis vascular access care, we performed a literature search from 1991 to 2021 and identified 2768 articles from 74 countries. The majority of publications originated from the United States (41.5%), followed by China (5.1%) and the United Kingdom (4.6%). Our search results comprise of observational studies (43%), case reports/series (27%), review articles (16.5%) and clinical trials (12%). A large proportion of articles were published in Nephrology journals (49%), followed by General Medicine (14%), Surgery (10%), Vascular Medicine (8%), and Interventional Radiology journals (4%). With the introduction of interventional nephrology, nephrologists will be able to assume the majority of the responsibility for dialysis vascular access care and above all maintain a close interdisciplinary collaboration with other specialties to provide optimum patient care. In this review article, we discuss the history, evolving knowledge, challenges, educational opportunities, and future directions of dialysis vascular access care, worldwide.

Impact of Postoperative Lumen Gain on the Reduction of Restenosis Risk after Endovascular Treatment using Drug-coated Balloon for Femoropopliteal Lesions Assessed by Intravascular Ultrasound

AIM

This study aimed to reveal whether a larger postprocedural minimum lumen area (MLA) would reduce restenosis risk after endovascular therapy (EVT) using drug-coated balloons (DCBs) in femoropopliteal (FP) lesions.

METHODS

This retrospective, nonrandomized, single-arm, and multicenter registry analyzed patients with FP lesions undergoing intravascular ultrasound (IVUS)-guided EVT with DCB between 2017 and 2021. The primary outcome was restenosis 1 year after EVT. The association between IVUS-based MLA and restenosis risk was investigated using a generalized propensity score (GPS) method to address imbalance of baseline covariates. The dose-response function of IVUS-measured MLA for restenosis risk was developed using the GPS-adjusted Cox proportional hazards regression model.

RESULTS

This study enrolled consecutive 489 patients with 595 lesions undergoing DCB treatment. The median MLA (interquartile range) was 13.20 (9.90-16.91) mm2. Kaplan-Meier estimates showed that freedom from restenosis was 84.4% at 1 year. The GPS-adjusted dose-response function showed that MLA was inversely associated with restenosis risk. The upper limit of 95% confidence interval (CI) of the slope was lower than 0 between 10.6 and 17.0 mm2 of MLAs. The 1-year cumulative incidence of restenosis was estimated to be 9.8% (95% CI, 5.8%-13.7%) for the 3rd quartile of MLA (16.91 mm2) versus 18.5% (12.3%-24.1%) for the 1st quartile (9.90 mm2), with a hazard ratio of 0.51 (95% CI, 0.39-0.67; p＜0.001).

CONCLUSIONS

The present GPS analysis suggested that larger IVUS-measured MLA might be associated with lower risk of 1-year restenosis after DCB treatment for FP lesions.

Transitions of dialysis status and outcomes after the unplanned first dialysis: a nationwide population-based cohort study

In Taiwan, most first-time dialysis was started without the creation of an arteriovenous shunt. Here, we aimed to elucidate the transitions of dialysis status in the unplanned first dialysis patients and determine factors associated with their outcomes. A total of 50,315 unplanned first dialysis patients aged more than 18 years were identified from the National Health Insurance Dataset in Taiwan between 2001 and 2012. All patients were followed for 5 years for the transitions in dialysis status, including robust (dialysis-free), sporadic dialysis, continued dialysis, and death. Furthermore, factors associated with the development of continued dialysis and death were examined by the Cox proportional hazard models. After 5 years after the first dialysis occurrence, there were 5.39% with robust status, 1.67% with sporadic dialysis, 8.45% with continued dialysis, and 84.48% with death. Notably, we have identified common risk factors for developing maintenance dialysis and deaths, including male gender, older age, diabetes, coronary heart disease, stroke, heart failure, sepsis, and surgery. There was an extremely high mortality rate among the first unplanned dialysis patients in Taiwan. Less than 10% of these patients underwent continued dialysis during the 5-year follow-up period. This study highlighted the urgent need for interventions to improve patient outcomes.

Roles of PTH and FGF23 in kidney failure: a focus on nonclassical effects

Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) each play a central role in the pathogenesis of chronic kidney disease-mineral and bone disorder (CKD-MBD). Both hormones increase as kidney function declines, presumably as a response to maintain normal phosphate balance, but when patients reach kidney failure, PTH and FGF23 fail to exert their phosphaturic effects, leading to hyperphosphatemia and further elevations in PTH and FGF23. In patients with kidney failure, the major target organ for PTH is the bone, but elevated PTH is also associated with mortality presumably through skeletal and nonskeletal mechanisms. Indeed, accumulated evidence suggests improved survival with PTH-lowering therapies, and a more recent study comparing parathyroidectomy and calcimimetic treatment further suggests a notion of "the lower, the better" for PTH control. Emerging data suggest that the link between SHPT and mortality could in part be explained by the action of PTH to induce adipose tissue browning and wasting. In the absence of a functioning kidney, the classical target organ for FGF23 is the parathyroid gland, but FGF23 loses its hormonal effect to suppress PTH secretion owing to the depressed expression of parathyroid Klotho. In this setting, experimental data suggest that FGF23 exerts adverse nontarget effects, but it remains to be confirmed whether FGF23 directly contributes to multiple organ injury in patients with kidney failure and whether targeting FGF23 can improve patient outcomes. Further efforts should be made to determine whether intensive control of SHPT improves clinical outcomes and whether nephrologists should aim at controlling FGF23 levels just as with PTH levels.

Serum Phosphorus Level Rises in US Hemodialysis Patients Over the Past Decade: A DOPPS Special Report

Mineral bone disorder (MBD) is a frequent consequence of chronic kidney disease, more so in patients with kidney failure treated by kidney replacement therapy. Despite the wide availability of interventions to control serum phosphate and parathyroid hormone levels, unmet gaps remain on optimal targets and best practices, leading to international practice pattern variations over time. In this Special Report, we describe international trends from the Dialysis Outcomes and Practice Patterns Study (DOPPS) for MBD biomarkers and treatments from 2002-2021, including data from a group of 7 European countries (Belgium, France, Germany, Italy, Spain, Sweden, United Kingdom), Japan, and the United States. From 2002-2012, mean phosphate levels declined in Japan (5.6 to 5.2 mg/dL), Europe (5.5 to 4.9 mg/dL), and the United States (5.7 to 5.0 mg/dL). Since then, levels rose in the United States (to mean 5.6 mg/dL, 2021), were stable in Japan (5.3 mg/dL), and declined in Europe (4.8 mg/dL). In 2021, 52% (United States), 27% (Europe), and 39% (Japan) had phosphate >5.5 mg/dL. In the United States, overall phosphate binder use was stable (80%-84% over 2015-2021), and parathyroid hormone levels rose only modestly. Although these results potentially stem from pervasive knowledge gaps in clinical practice, the noteworthy steady increase in serum phosphate in the United States over the past decades may be consequential to patient outcomes, an uncertainty that hopefully will soon be addressed by ongoing clinical trials. The DOPPS will continue to monitor international trends as new interventions and strategies ensue for MBD management in chronic kidney disease.

Changes in spike protein antibody titer over 90 days after the second dose of SARS-CoV-2 vaccine in Japanese dialysis patients

OBJECTIVES

There is no report on antibody titers after vaccination against SARS-CoV-2 in Japanese dialysis patients. As dialysis is different between Japan and other countries, changes in antibody titers were examined.

METHODS

Baseline characteristics and anti-spike protein antibody titers (Roche) over 90 days after administration of the BNT162b2 messenger RNA vaccine were investigated in dialysis patients.

RESULTS

The maximum anti-spike protein antibody titer after the second dose was 738 (327 to 1143) U/mL and was reached at 19 (17 to 24) days after the second dose. Antibody titers decreased over time, with titers of 770 (316 to 1089) U/mL at 15 days, 385 (203 to 690) U/mL at 30 days, 254 (138 to 423) U/mL at 60 days, and 208 (107 to 375) U/mL at 90 days after the second dose. When an antibody titer of 137 U/mL was assumed to be a measure related to breakthrough infection, the proportion of subjects with antibody titers exceeding this level was 90.1% at 15 days, 85.3% at 30 days, 75.0% at 60 days, and 65.4% at 90 days after the second dose. When a decrease in antibody titers below the assumed breakthrough level was defined as an event, subjects with a pre-dialysis albumin ≥ 3.5 g/dL were significantly less likely to experience an event than subjects with a pre-dialysis albumin < 3.5 g/dL.

CONCLUSIONS

The presence of anti-spike protein levels ≥ 313 U/mL at 30 days after the second vaccine dose might be a factor in maintaining enough antibody titers at 90 days after. Whether an additional vaccine dose is needed should be determined based on indicators serving as factors in maintaining antibody titers as well as the status of the spread of infection.

Additional effect of hemodialysis on mortality estimated from renal function in ischemic heart disease

Aim: The present study examined whether hemodialysis in patients with ischemic heart disease increases mortality more than the estimated mortality from renal function. Patients & methods: A total of 1621 patients with angina pectoris (n = 815), ST-elevation myocardial infarction (n = 421) or non-ST-elevation acute coronary syndrome (n = 385) were examined. An estimated mortality curve according to the estimated glomerular filtration rate was drawn using the marginal effect from the logit model. The probability of mortality in patients with hemodialysis was plotted on these curves. Results: The probability of mortality in patients undergoing hemodialysis crossed the estimated mortality curves at the estimated glomerular filtration rate of 5.7 ml/min/1.73 m² in angina pectoris, 31.3 ml/min/1.73 m² in STEMI and 45.9 ml/min/1.73 m² in non-ST-elevation acute coronary syndrome. Conclusion: Hemodialysis does not have an additional adverse impact on the estimated mortality.

Psoas muscle index and psoas muscle density as predictors of mortality in patients undergoing hemodialysis

This study aimed to investigate the associations of computed tomography (CT)-measured psoas muscle index (PMI: psoas muscle area normalized by height) and psoas muscle density (PMD: average of bilateral psoas muscle CT values [Hounsfield unit (HU)]) with mortality in patients undergoing hemodialysis. We included 188 hemodialysis patients who underwent abdominal CT. PMI and PMD were measured at the third lumbar vertebral level. We found that PMI and PMD were independently associated with the geriatric nutritional risk index and log C-reactive protein, respectively. The optimal cut-off values of PMI and PMD for men and women were 3.39 cm²/m² and 41.6 HU, and 2.13 cm²/m² and 37.5 HU, respectively. During follow-up (median 3.5 years), 69 patients died. Lower PMI and lower PMD were independently associated with an increased risk of all-cause mortality [adjusted hazard ratio (aHR) 2.05, 95% confidence interval (CI) 1.14–3.68; aHR 3.67, 95% CI 2.04–6.60), respectively]. The aHR for lower PMI and lower PMD vs. higher PMI and higher PMD was 5.34 (95% CI 2.38–11.97). The addition of PMI and PMD to the risk model significantly improved C-index from 0.775 to 0.893 (p < 0.00001). The combination of PMI and PMD may improve mortality prediction in patients undergoing hemodialysis.

Long-term Outcomes Among Patients With Advanced Kidney Disease Who Forgo Maintenance Dialysis: A Systematic Review

IMPORTANCE

An understanding of the long-term outcomes of patients with advanced chronic kidney disease not treated with maintenance dialysis is needed to improve shared decision-making and care practices for this population.

OBJECTIVE

To evaluate survival, use of health care resources, changes in quality of life, and end-of-life care of patients with advanced kidney disease who forgo dialysis.

EVIDENCE REVIEW

MEDLINE, Embase (Excerpta Medica Database), and CINAHL (Cumulative Index of Nursing and Allied Health Literature) were searched from inception through December 3, 2021, for all English language longitudinal studies of adults in whom there was an explicit decision not to pursue maintenance dialysis. Two investigators independently reviewed all studies and selected those reporting survival, use of health care resources, changes in quality of life, or end-of-life care during follow-up. Studies of patients who initiated and then discontinued maintenance dialysis and patients in whom it was not clear that there was an explicit decision to forgo dialysis were excluded. One author abstracted all study data, of which 12% was independently adjudicated by a second author (<1% error rate).

FINDINGS

Forty-one cohort studies comprising 5102 patients (range, 11-812 patients) were included in this systematic review (5%-99% men; mean age range, 60-87 years). Substantial heterogeneity in study designs and measures used to report outcomes limited comparability across studies. Median survival of cohorts ranged from 1 to 41 months as measured from a baseline mean estimated glomerular filtration rate ranging from 7 to 19 mL/min/1.73 m2. Patients generally experienced 1 to 2 hospital admissions, 6 to 16 in-hospital days, 7 to 8 clinic visits, and 2 emergency department visits per person-year. During an observation period of 8 to 24 months, mental well-being improved, and physical well-being and overall quality of life were largely stable until late in the illness course. Among patients who died during follow-up, 20% to 76% had enrolled in hospice, 27% to 68% died in a hospital setting and 12% to 71% died at home; 57% to 76% were hospitalized, and 4% to 47% received an invasive procedure during the final month of life.

CONCLUSIONS AND RELEVANCE

Many patients who do not pursue dialysis survived several years and experienced sustained quality of life until late in the illness course. Nonetheless, use of acute care services was common and intensity of end-of-life care highly variable across cohorts. These findings suggest that consistent approaches to the study of conservative kidney management are needed to enhance the generalizability of findings and develop models of care that optimize outcomes among conservatively managed patients.

Epidemiology of haemodialysis outcomes

Haemodialysis (HD) is the commonest form of kidney replacement therapy in the world, accounting for approximately 69% of all kidney replacement therapy and 89% of all dialysis. Over the last six decades since the inception of HD, dialysis technology and patient access to the therapy have advanced considerably, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes vary widely across the world and, overall, the rates of impaired quality of life, morbidity and mortality are high. Cardiovascular disease affects more than two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality. In addition, patients on HD have high symptom loads and are often under considerable financial strain. Despite the many advances in HD technology and delivery systems that have been achieved since the treatment was first developed, poor outcomes among patients receiving HD remain a major public health concern. Understanding the epidemiology of HD outcomes, why they might vary across different populations and how they might be improved is therefore crucial, although this goal is hampered by the considerable heterogeneity in the monitoring and reporting of these outcomes across settings.

This Review examines the epidemiology of haemodialysis outcomes — clinical, patient-reported and surrogate outcomes — across world regions and populations, including vulnerable individuals. The authors also discuss the current status of monitoring and reporting of haemodialysis outcomes and potential strategies for improvement.

Nearly 4 million people in the world are living on kidney replacement therapy (KRT), and haemodialysis (HD) remains the commonest form of KRT, accounting for approximately 69% of all KRT and 89% of all dialysis.

Dialysis technology and patient access to KRT have advanced substantially since the 1960s, particularly in high-income countries. However, HD availability, accessibility, cost and outcomes continue to vary widely across countries, particularly among disadvantaged populations (including Indigenous peoples, women and people at the extremes of age).

Cardiovascular disease affects over two-thirds of people receiving HD, is the major cause of morbidity and accounts for almost 50% of mortality; mortality among patients on HD is significantly higher than that of their counterparts in the general population, and treated kidney failure has a higher mortality than many types of cancer. Patients on HD also experience high burdens of symptoms, poor quality of life and financial difficulties.

Careful monitoring of the outcomes of patients on HD is essential to develop effective strategies for risk reduction. Outcome measures are highly variable across regions, countries, centres and segments of the population. Establishing kidney registries that collect a variety of clinical and patient-reported outcomes using harmonized definitions is therefore crucial.

Evaluation of HD outcomes should include the impact on family and friends, and personal finances, and should examine inequities in disadvantaged populations, who comprise a large proportion of the HD population.

Combined Evaluation of Geriatric Nutritional Risk Index and Modified Creatinine Index for Predicting Mortality in Patients on Hemodialysis

The geriatric nutritional risk index (GNRI) and modified creatinine index (mCI) are surrogate markers of protein-energy wasting in patients receiving hemodialysis. We aimed to examine whether a combined evaluation of these indices improved mortality prediction in this population. We retrospectively investigated 263 hemodialysis patients divided into two groups, using 91.2 and 20.16 mg/kg/day as cut-off values of GNRI and mCI, respectively. The resultant four groups were reshuffled into four subgroups defined using combinations of cut-off values of both indices and were followed up. During the follow-up period (median: 3.1 years), 103 patients died (46/103, cardiovascular causes). Lower GNRI and lower mCI were independently associated with all-cause mortality (adjusted hazard ratio (aHR) 4.96, 95% confidence intervals (CI) 3.10–7.94, and aHR 1.92, 95% CI 1.22–3.02, respectively). The aHR value for the lower GNRI and lower mCI group vs. the higher GNRI and higher mCI group was 7.95 (95% CI 4.38–14.43). Further, the addition of GNRI and mCI to the baseline risk assessment model significantly improved the C-index of all-cause mortality (0.801 to 0.835, p = 0.025). The simultaneous evaluation of GNRI and mCI could be clinically useful to stratify the risk of mortality and to improve the predictability of mortality in patients on hemodialysis.

Impact of Hemodialysis on Clinical Outcomes in Patients Undergoing Lower Extremity Bypass Surgery for Peripheral Artery Disease-10-year Follow-Up Study

We investigated the clinical impact of hemodialysis on long-term outcomes of bypass surgery in patients with peripheral artery disease. We evaluated 660 consecutive patients who underwent successful bypass surgery (392 hemodialysis and 268 non-hemodialysis). The endpoint was amputation-free survival (AFS). To minimize differences in clinical characteristics between the 2 groups, propensity score matching was performed. The AFS rates for 10-year follow-up were 39.3% and 67.7% in hemodialysis and non-hemodialysis patients [hazard ratio (HR) 2.21, 95% confidence interval (CI) 1.65-3.01, P < .0001]. Cumulative incidence of amputation was higher in the hemodialysis group than in the non-hemodialysis group [(19.4 vs 8.4%, HR 2.15, 95% CI 1.29-3.74, P = .0027). In a matched cohort (n = 210 each), AFS was still lower in the hemodialysis patients (53.1 vs 66.3%, HR 1.94, 95% CI 1.36-2.82, P = .0003). However, there was no significant difference in amputation rate between the groups (10.5 vs 10.6%, HR .97, 95% CI 0.49-1.87, P = .93). In a sub-analysis of patients with critical limb ischemia, similar results were obtained. The 10-year AFS was consistently lower in the hemodialysis group than in the non-hemodialysis group. However, the amputation rate was comparable between the groups when matched for the differences in clinical characteristics.

Stratification Analysis of Statin Effect on Major Adverse Cardiac Events After Percutaneous Coronary Intervention in Patients on Hemodialysis

ABSTRACT

The statin use in patients on hemodialysis remains controversial, and no beneficial effects of statin on the reduction of adverse cardiovascular events have been reported in these patients. This study used stratification analysis to examine the clinical factors in patients on hemodialysis who could benefit from statin for secondary prevention. This prospective multicenter study included 234 consecutive patients on hemodialysis with coronary artery disease who underwent successful reperfusion therapy with percutaneous coronary intervention. The patients were followed up for up to 3 years or until the occurrence of major adverse cardiac events (MACEs; defined as a composite of all-cause death and nonfatal myocardial infarction). Inverse probability of treatment weighting adjustment was used to remove the selection bias. During the median follow-up period of 30 months, MACEs occurred in 55 patients. Patients with MACEs had significantly lower statin therapy (P < 0.001). Multivariable Cox proportional hazards analysis showed that the patients on statins had a significantly reduced rate of MACE occurrence [adjusted hazard ratio 0.30 (0.11-0.81), P = 0.02]. The stratification analysis of outcomes according to the presence of clinical factors showed that beneficial effects of statin were associated with man, elderly, lower body mass index, lower abdominal circumference, hypertension, diabetes, higher C-reactive protein, symptomatic heart failure, lower left ventricular function, nonacute coronary syndrome, and shorter stent length. Statin was effective for the prevention of MACEs in patients on hemodialysis who underwent percutaneous coronary intervention. We identified specific clinical factors affecting statin effectiveness for secondary prevention.

The prevalence of predialysis hyperkalemia and associated characteristics among hemodialysis patients: The RE-UTILIZE study

Introduction

Hyperkalemia (HK), defined as serum potassium (K⁺) >5.0 mEq/L, is an independent predictor of mortality in patients on maintenance hemodialysis (HD). This study investigated the annual prevalence of HK and examined patient characteristics potentially associated with a higher annual HK prevalence.

Methods

This retrospective observational cohort study used Dialysis Outcomes and Practice Patterns Study (DOPPS) survey data from US patients undergoing in‐center HD thrice weekly from 2018 to 2019. The primary endpoint was the proportion of patients with any predialysis HK (K⁺ >5.0 mEq/L) within 1 year from the index date (date of DOPPS enrollment), using the first hyperkalemic K⁺ value. Secondary endpoints were the proportion of patients with moderate‐to‐severe (K⁺ >5.5 mEq/L) or severe (K⁺ >6.0 mEq/L) HK.

Findings

Overall, 9347 patients on HD were included in this analysis (58% male and 49% aged >66 years). Any predialysis HK (K⁺ >5.0 mEq/L) occurred in 74% of patients within 1 year of the index date, 52% within 3 months, and 38% within 1 month. The annual prevalence of moderate‐to‐severe and severe HK was 43% and 17%, respectively. Recurrent HK (at least two K⁺ >5.0 mEq/L within 1 year) occurred in 60% of patients, and 2.8% of patients were prescribed an oral K⁺ binder. Multivariable logistic regression analysis showed younger age, female sex, Hispanic ethnicity, and renin–angiotensin–aldosterone system inhibitor use were significantly associated with a higher annual prevalence of any predialysis HK, while Black race, obesity, recent initiation of HD, and dialysate K⁺ bath concentration ≥3 mEq/L were associated with a lower prevalence of HK.

Discussion

The annual prevalence of predialysis HK and recurrence were high among US patients on HD, whereas oral K⁺ binder use was low. Further studies are needed to understand the impact of dialysate K⁺ bath concentrations on predialysis HK among patients on HD.

Practice variations in antibiotic administration for the management of peritonitis in patients on automated peritoneal dialysis in Australia and New Zealand

In the absence of guidelines on the management of peritoneal dialysis (PD)-associated peritonitis in patients on automated peritoneal dialysis (APD), variations in clinical practice potentially exist between PD units that could affect clinical outcomes. This study aimed to document the current practices of treating PD-associated peritonitis in patients on APD across Australia and New Zealand and the reasons for practice variations using a cross-sectional online survey. Of the 62 PD units, 34 medical leads (55%) responded to the survey. When treating APD-associated peritonitis, 21 units (62%) continued patients on APD and administered intraperitoneal (IP) antibiotics in manual daytime exchanges; of these, 17 (81%) considered allowing at least 6 h dwell time for adequate absorption of the IP antibiotics as an important reason for adding manual daytime exchange. Nine units (26%) temporarily switched patients from APD to continuous ambulatory peritoneal dialysis (CAPD); of these, five (55%) reported a lack of pharmacokinetic (PK) data for IP antibiotics in APD, four (44%) reported a shortage of APD-trained nursing staff to perform APD exchanges during hospitalisation and three (33%) reported inadequate time for absorption of IP antibiotics on APD as important reasons for their practice. Four units (12%) continued patients on APD and administered IP antibiotics during APD exchanges; of these, three (75%) believed that PK data available in CAPD could be extrapolated to APD. This study demonstrates wide variations in the management of APD-associated peritonitis in Australia and New Zealand; it points towards the lack of PK on antibiotics used to treat peritonitis as an important reason underpinning practice variations.

Tracing all patients who received insured dialysis treatment in Japan and the present situation of their number of deaths

Background

The survival rate of chronic dialysis patients in Japan remains the highest worldwide, so there is value in presenting Japan’s situation internationally. We examined whether aggregate figures on dialysis patients in the National Database of Health Insurance Claims and Special Health Checkups of Japan (NDB), which contains data on insured procedures of approximately 100 million Japanese residents, complement corresponding figures in the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR).

Methods

Subjects were patients with medical fee points for dialysis recorded in the NDB during 2014–2018. We analyzed annual numbers of dialysis cases, newly initiated dialysis cases– and deaths.

Results

Compared with the JRDR, the NDB had about 6–7% fewer dialysis cases but a similar number of newly initiated dialysis cases. In the NDB, the number of deaths was about 6–10% lower, and the number of hemodialysis cases was lower, while that of peritoneal dialysis cases was higher. The cumulative survival rate at dialysis initiation was approximately 6 percentage points lower in the NDB than in the JRDR, indicating that some patients die at dialysis initiation. Cumulative survival rate by age group was roughly the same between the NDB and JRDR in both sexes.

Conclusion

The use of the NDB enabled us to aggregate data of dialysis patients. With the definition of dialysis patients used in this study, analyses of concomitant medications, comorbidities, surgeries, and therapies will become possible, which will be useful in many future studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02163-z.

Choices in hemodialysis therapies: variants, personalized therapy and application of evidence-based medicine

The extent of removal of the uremic toxins in hemodialysis (HD) therapies depends primarily on the dialysis membrane characteristics and the solute transport mechanisms involved. While designation of ‘flux’ of membranes as well toxicity of compounds that need to be targeted for removal remain unresolved issues, the relative role, efficiency and utilization of solute removal principles to optimize HD treatment are better delineated. Through the combination and intensity of diffusive and convective removal forces, levels of concentrations of a broad spectrum of uremic toxins can be lowered significantly and successfully. Extended clinical experience as well as data from several clinical trials attest to the benefits of convection-based HD treatment modalities. However, the mode of delivery of HD can further enhance the effectiveness of therapies. Other than treatment time, frequency and location that offer clinical benefits and increase patient well-being, treatment- and patient-specific criteria may be tailored for the therapy delivered: electrolytic composition, dialysate buffer and concentration and choice of anticoagulating agent are crucial for dialysis tolerance and efficacy. Evidence-based medicine (EBM) relies on three tenets, i.e. clinical expertise (i.e. doctor), patient-centered values (i.e. patient) and relevant scientific evidence (i.e. science), that have deviated from their initial aim and summarized to scientific evidence, leading to tyranny of randomized controlled trials. One must recognize that practice patterns as shown by Dialysis Outcomes and Practice Patterns Study and personalization of HD care are the main driving force for improving outcomes. Based on a combination of the three pillars of EBM, and particularly on bedside patient–clinician interaction, we summarize what we have learned over the last 6 decades in terms of best practices to improve outcomes in HD patients. Management of initiation of dialysis, vascular access, preservation of kidney function, selection of biocompatible dialysers and use of dialysis fluids of high microbiological purity to restrict inflammation are just some of the approaches where clinical experience is vital in the absence of definitive scientific evidence. Further, HD adequacy needs to be considered as a broad and multitarget approach covering not just the dose of dialysis provided, but meeting individual patient needs (e.g. fluid volume, acid–base, blood pressure, bone disease metabolism control) through regular assessment—and adjustment—of a series of indicators of treatment efficiency. Finally, in whichever way new technologies (i.e. artificial intelligence, connected health) are embraced in the future to improve the delivery of dialysis, the human dimension of the patient–doctor interaction is irreplaceable. Kidney medicine should remain ‘an art’ and will never be just ‘a science’.

The global impact of the Coronavirus 2019 pandemic on in-centre haemodialysis services: an International Society of Nephrology -Dialysis Outcomes Practice Patterns Study survey

Introduction

To assess the impact of the COVID-19 pandemic impact on hemodialysis (HD) centers, The Dialysis Outcomes and Practice Patterns Study and ISN collaborated on a web-survey of centers.

Methods

A combined approach of random sampling and open invitation was used between March 2020 and March 2021. Responses were obtained from 412 centers in 78 countries and all 10 ISN regions.

Results

In 8 regions, rates of SARS-CoV-2 infection were <20% in most centers, but in North East Asia (NE Asia) and Newly Independent States and Russia (NIS & Russia), rates were ≥20% and ≥30%, respectively. Mortality was ≥10% in most centers in 8 regions, although lower in North America and Caribbean (N America & Caribbean) and NE Asia. Diagnostic testing was not available in 33%, 37%, and 61% of centers in Latin America, Africa, and East and Central Europe, respectively. Surgical masks were widely available, but severe shortages of particulate-air filter masks were reported in Latin America (18%) and Africa (30%). Rates of infection in staff ranged from 0% in 90% of centers in NE Asia to ≥50% in 63% of centers in the Middle East and 68% of centers in NIS & Russia. In most centers, <10% of staff died, but in Africa and South Asia (S Asia), 2% and 6% of centers reported ≥50% mortality, respectively.

Conclusion

There has been wide global variation in SARS-CoV-2 infection rates among HD patients and staff, personal protective equipment (PPE) availability, and testing, and the ways in which services have been redesigned in response to the pandemic.

Representativeness of the PDOPPS cohort compared to the Australian PD population

BACKGROUND

The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) is an international, prospective study following persons treated by peritoneal dialysis (PD) to identify modifiable practices associated with improvements in PD technique and person survival. The aim of this study was to assess the representativeness of the Australian cohort included in PDOPPS compared to the complete Australian PD population, as reported to the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry.

METHODS

Adults with at least one PD treatment reported to ANZDATA Registry during the census period of PDOPPS Phase I (November 2014 to April 2018) were compared to the Australian PDOPPS cohort. The primary outcomes were the representativeness of centres and persons. Secondary outcomes explored the association of person characteristics with consent to study participation.

RESULTS

After data linkage, 511 PDOPPS participants were compared to 5616 Australians treated with PD. Within centres eligible for PDOPPS, selected centres were similar to other Australian centres. The PDOPPS participants' cohort tended to include older persons, more males, a higher proportion of Caucasians and more persons with higher socioeconomic advantage compared to the Australian PD population. Differences in distribution across sex and ethnicities between the PDOPPS cohort and the overall PD population were in part due to the selection and consent processes, during which females and non-Caucasians were more likely to not consent to PDOPPS participation.

CONCLUSION

Sampling methods used in PDOPPS allowed for good national representativeness of the included centres. However, representativeness of the unweighted PDOPPS sample was suboptimal in regard to some participant characteristics.

Mid-term clinical outcomes and complications of primary total knee arthroplasty in hemodialysis patients: a retrospective comparative cohort study

Background

Numerous patients who receive hemodialysis (HD) undergo total knee arthroplasty (TKA) due to advanced knee joint arthritis. However, there are few studies that describe the clinical outcomes and complications of TKA in HD patients. This study investigated the mid-term results of TKA in patients undergoing HD.

Methods

This single-center retrospective study compared clinical and surgical outcomes following TKA in patients who were receiving HD with those who were not. We used propensity scores to match 21 knees of 18 patients who received HD to 706 knees of 569 patients who had not received HD, from a total of 727 knees (587 patients) that underwent primary unilateral TKA. The clinical outcomes were evaluated using the American Knee Society Score-knee (AKSS-knee) and AKSS-function scores. The primary surgical outcome measure was the number of knees with postoperative complications.

Results

In both the HD and non-HD groups, postoperative AKSS-knee and function scores significantly improved when compared to preoperative values. Postoperative AKSS-knee and function scores were not significantly different between the groups. The number of knees with postoperative complications was larger in the HD group than the non-HD group within the first postoperative month, 0–12 months, 12–24 months, 0–24 months, and two years after surgery. Additionally, in the HD group, more complications occurred in the first month than any subsequent month in the two years after surgery.

Conclusions

TKA improves AKSS-knee and function scores equivalently for HD patients and non-HD patients. However, HD patients develop more complications after TKA, especially within the first month. Therefore, surgeons who perform TKA for HD patients should obtain informed consent after explaining the possible complications, and HD patients should be carefully observed following TKA.

High-flow arteriovenous fistula and hemodynamic consequences at 1 year after kidney transplantation

INTRODUCTION

There are only scarce data regarding the cardiovascular impact of arteriovenous fistula after kidney transplantation depending on fistula flow.

METHODS

We performed a single-center, prospective, cohort study including 49 patients with a functional fistula at 1 year from kidney transplantation. Patients were convened for a clinical work-up, a biological analysis, a fistula's Doppler ultrasonography and an echocardiography. Main judgment criterion was comparison of echocardiography parameters between patients with relative (fistula flow >1 L/min and a fistula flow/cardiac output ratio >20%), absolute high-flow fistula (fistula flow >2 L/min) and normal-flow fistula.

RESULTS

High-flow fistula frequency was 69%. Significantly higher left ventricular end-diastolic and systolic diameters were observed in this group compared with the normal-flow fistula group (53 ± 6 vs. 48 ± 7 mm; p = 0.04 and 33 ± 6 vs. 28 ± 8 mm; p = 0.02) and between the absolute and relative high-flow fistula subgroups (56 ± 6 vs. 51 ± 6 mm; p = 0.009 and 35 ± 6 vs. 31 ± 5 mm; p = 0.01). The study showed no other significant differences.

CONCLUSIONS

This study showed a significantly higher but not pathological left ventricular end-diastolic and systolic diameters values in patients with high-flow fistula compared with patients with normal-flow fistula and between patients with respectively absolute and relative high-flow fistula.

Changes in practice patterns in Japan from before to after JSDT 2013 guidelines on hemodialysis prescriptions: results from the JDOPPS

BACKGROUND

The Japanese Society for Dialysis Therapy (JSDT) published in 2013 inaugural hemodialysis (HD) guidelines. Specific targets include 1.4 for single-pool Kt/V (spKt/V) with a minimum dose of 1.2, minimum dialysis session length of 4 hours, minimum blood flow rate (BFR) of 200 mL/min, fluid removal rate no more than 15 mL/kg/hr, and hemodiafiltration (HDF) therapy for certain identified symptoms. We evaluated the effect of these guidelines on actual practice in the years spanning 2005 - 2018.

METHODS

Analyses were carried out to describe trends in the above HD prescription practices from December 2005 to April 2013 (before guideline publication) to August 2018 based on prevalent patient cross-sections from approximately 60 randomly selected HD facilities participating in the Japan Dialysis Outcomes and Practice Patterns Study.

RESULTS

From April 2006 to August 2017 continual rises occurred in mean spKt/V (from 1.35 to 1.49), and percent of patients having spKt/V>1.2 (71% to 85%). Mean BFR increased with time from 198.3 mL/min (April 2006) to 218.4 mL/min (August 2017) , along with percent of patients with BFR >200 ml/min (65% to 85%). HDF use increased slightly from 6% (April 2006 and August 2009) to 8% by April 2013, but increased greatly thereafter to 23% by August 2017. In contrast, mean HD treatment time showed little change from 2006-2017, whereas mean UFR declined from 11.3 in 2006 to 8.4 mL/Kg/hour in 2017.

CONCLUSIONS

From 2006 - 2018 Japanese HD patients experienced marked improvement in reaching the spKt/V target specified by the 2013 JSDT guidelines. This may have been due to moderate increase in mean BFR even though mean HD session length did not change much. In addition, HDF use increased dramatically in this time period. Other HD delivery changes during this time, such as increased use of super high flux dialyzers, also merit study. While we cannot definitively conclude a causal relationship between the publication of the guidelines and the subsequent practice changes in Japan, those changes moved practice closer to the recommendations of the guidelines.

Big Data in Nephrology

A huge array of data in nephrology is collected through patient registries, large epidemiological studies, electronic health records, administrative claims, clinical trial repositories, mobile health devices and molecular databases. Application of these big data, particularly using machine-learning algorithms, provides a unique opportunity to obtain novel insights into kidney diseases, facilitate personalized medicine and improve patient care. Efforts to make large volumes of data freely accessible to the scientific community, increased awareness of the importance of data sharing and the availability of advanced computing algorithms will facilitate the use of big data in nephrology. However, challenges exist in accessing, harmonizing and integrating datasets in different formats from disparate sources, improving data quality and ensuring that data are secure and the rights and privacy of patients and research participants are protected. In addition, the optimism for data-driven breakthroughs in medicine is tempered by scepticism about the accuracy of calibration and prediction from in silico techniques. Machine-learning algorithms designed to study kidney health and diseases must be able to handle the nuances of this specialty, must adapt as medical practice continually evolves, and must have global and prospective applicability for external and future datasets.

Usefulness of computed tomography-measured psoas muscle thickness per height for predicting mortality in patients undergoing hemodialysis

Computed tomography (CT)-measured psoas muscle thickness standardized for height (PMTH) has emerged as a promising predictor of mortality. The study aimed to investigate whether PMTH could accurately predict mortality in patients undergoing hemodialysis. We examined 207 patients (mean age: 63.1 years; men: 66.2%) undergoing hemodialysis for more than 6 months in hospital affiliated clinic. PMTH was calculated at the L3 vertebra level using CT. Patients were divided according to the PMTH cut-off points: 8.44 mm/m in women and 8.85 mm/m in men; thereafter, they were combined into low and high PMTH groups. PMTH was independently correlated with the simplified creatinine index (β = 0.213, P = 0.021) and geriatric nutritional risk index (β = 0.295, P < 0.0001) in multivariate regression analysis. During a median follow-up of 3.7 (1.8–6.4) years, 76 patients died, including 41 from cardiovascular causes. In the multivariate Cox regression analysis, low PMTH (adjusted hazard ratio, 2.48; 95% confidence interval, 1.36–4.70) was independently associated with an increased risk of all-cause mortality. The addition of binary PMTH groups to the baseline risk model tended to improve net reclassification improvement (0.460, p = 0.060). In conclusion, PMTH may be an indicator of protein energy wasting and a useful tool for predicting mortality in patients undergoing hemodialysis.

Association between facility-level adherence to phosphorus management guidelines and mortality in haemodialysis patients: a prospective cohort study

OBJECTIVES

To examine the association between facility-level adherence to phosphorus management guidelines and mortality among patients with haemodialysis, and to explore the facility-related factors associated with facility-level guideline adherence.

DESIGN

Prospective cohort study.

SETTING

The Dialysis Outcomes and Practice Pattern Study, which included 57 representative dialysis facilities in Japan between 2012 and 2015.

PARTICIPANTS

A total of 2054 adult patients who received maintenance haemodialysis were included. We defined exposure according to the following four categories, depending on whether facility-level target ranges of serum phosphorus concentration adhered to the Japanese clinical practice guidelines: adherence group (lower limit ≥3.5 mg/dL and upper limit ≤6.0 mg/dL), low-target group (lower limit <3.5 and upper limit ≤6.0), wide-target group (lower limit <3.5 and upper limit >6.0) and high-target group (lower limit ≥3.5 and upper limit >6.0).

PRIMARY OUTCOME MEASURE

The primary outcome was the patient all-cause mortality rate.

RESULTS

The mortality rate among the patients was 7.3 per 100 person-years; 27 facilities (47%) set targets according to the guidelines. HRs for mortality with reference to the adherence group were 1.04 (95% CI 0.76 to 1.43) in the low-target group, 1.11 (95% CI 0.68 to 1.81) in the wide-target group and 1.95 (95% CI 1.12 to 3.38) in the high-target group. Involvement of dieticians in dialysis treatment was associated with facility-level guideline adherence (OR 4.51; 95% CI 1.15 to 17.7).

CONCLUSIONS

A higher facility-level target range for phosphorus was associated with increased patient mortality. Among facilities that set the target according to the guidelines, dieticians tended to be involved in dialysis care. These findings suggest the importance of reviewing facilities' treatment policies in relation to updated guidelines and the need to work with relevant professionals.

Influence of Tunneled Hemodialysis-Catheters on Inflammation and Mortality in Dialyzed Patients

Older age and comorbidities in hemodialysis patients determines the use of tunneled catheters as vascular access despite their reported clinical and mortality disadvantages. This prospective matched study analyzes the impact of permanent catheters on inflammation and mortality in hemodialysis patients; We studied 108 patients, 54 with AV-fistula (AVF) and 54 with indwelling hemodialysis catheters (HDC) matched by sex, age, diabetes and time under renal-replacement therapy comparing dialysis efficacy, inflammation and micro-inflammation parameters as well as mortality. Cox-regression analysis was applied to determine predictors of mortality, HDC patients presented higher C-reactive-protein (CRP) blood levels and percentage of pro-inflammatory lymphocytes CD14+/CD16+ with worse dialysis-efficacy parameters. Thirty-six-months mortality appeared higher in the HDC group although statistical significance was not reached. Age with a Hazard Ratio (HR) = 1.06, hypoalbuminemia (HR = 0.43), hypophosphatemia (HR = 0.75) and the increase in CD14+/CD16+ monocyte count (HR = 1.02) were predictors of mortality; elder patients dialyzing through HDC show increased inflammation parameters as compared with nAVF bearing patients, although they do not present a significant increase in mortality when matched by covariates. Increasing age and percentage of pro-inflammatory monocytes as well as decreased phosphate and serum-albumin were predictors of mortality and indicate the main conclusions or interpretations.

A new insight into the treatment of renal anemia with HIF stabilizer

The long-term clinical experiences with recombinant human erythropoietin (rHuEPO) and its analog derivatives have clearly proven that correction of anemia with erythropoiesis stimulating agent (ESA) not only reduces blood transfusion and improves patients’ QOL but has multiple benefits for the concurrent complications of CKD such as Cardio-Renal–Anemia (CRA) syndrome and/or malnutrition-inflammation-atherosclerosis (MIA) syndrome.

Unlike ESA, the newly available agent, hypoxia-inducible factor (HIF) stabilizer, stimulates endogenous erythropoietin (EPO) by mimicking hypoxia with HIF prolyl hydroxylase domain enzyme (HIF-PHD) inhibition. The phase 2 and 3 clinical studies have shown that HIF stabilizers are as efficacious as ESA in ameliorating renal anemia. Whether the same clinical benefits on CRA and MIA syndrome hold true in patients given HIF stabilizers is a matter for future debate. Given that HIF stabilizers act on the multiple target genes, the use of this novel agent may lead to unwanted adverse events.

Launching HIF stabilizers into the treatment of renal anemia provokes a concern about how this alternative treatment will be taken up in the daily clinical practice. However, guideline-oriented strategies on how to use HIF stabilizer is not available at this limited point due to scant clinical information. Nevertheless, this opinion-based review provides a future insight into the management of renal anemia with HIF stabilizer by reference to the past experiences with ESA. HIF stabilizers can preferably be indicated for CRA syndrome at pre-dialysis stage, ESA resistant anemia at advanced CKD stage, and perhaps for dysregulated iron metabolism akin to MIA syndrome in patients on dialysis.

Calculation of expected remaining lifetime of dialysis patients in Japan

Background

The expected remaining lifetime of dialysis patients in Japan was only reported in 2003 and has not been reported thereafter. From 2003 to the present, several new therapeutic agents have been introduced. These events may have improved outcomes for dialysis patients. Thus, expected remaining lifetime of dialysis patients in Japan was newly calculated in 2015.

Methods

The Japanese Society for Dialysis Therapy Renal Data Registry database was used for analyses. From this database, the following three indexes were compiled: the number of surviving dialysis patients (198,125 males and 111,962 females) at the end of 2014 and the number of surviving (179,649 males and 101,758 females) and dead (18,044 males and 111,417 females) patients at the end of 2015. Based on these values, expected remaining lifetime at 1-year increment was calculated using the life table method.

Results

Excerpts of the calculated expected remaining lifetimes of patients aged 60 years were as follows: 11.9 years for males and 14.1 years for females. These expected remaining lifetimes were 1.1 to 1.2 times as compared with those in 2003. Meanwhile, expected remaining lifetime of diabetic patients was 10.8 years for males and 12.5 years for females and that of nondiabetic patients was 13.0 years for males and 15.0 years for females.

Conclusion

Expected remaining lifetime of dialysis patients in Japan in 2015 was 10–20% longer than that in 2003. These results suggest that advances in dialysis technologies during this 12-year period improved the survival rate of dialysis patients.

Achieving dialysis adequacy: A global perspective

Dialysis adequacy is conventionally quantified as net urea clearance. Single pool (sp) Kt/V_urea remains the best studied measure of dialysis adequacy globally. Other measures such as fluid status control, anemia correction, and mineral metabolism are monitored variably. Increasing use of hemodiafiltration across Europe and many parts of Japan and Australia is predicated on studies showing better patient survival with middle molecule clearance. Apart from local clinical practice guidelines, the income level and public health policy of a country determine quality of dialysis services. Among developed nations, small solute clearance adequacy targets are achieved with high frequency. In the United States, dialysis adequacy target is met by focussing on high blood flow rates and large dialyzer size, sometimes at the cost of session time. In Japan, Australia, and Germany, session length is given importance. Dialysis adequacy reporting is restricted and inconsistent in developing nations. The Gulf Cooperation Council countries, Russia and Malaysia, respectively, are close to achieving dialysis adequacy target (spKt/V_urea ≥1.2) universally in their dialysis populations. Patient-reported outcomes are typically measured only in developed countries. Patient survival on dialysis, partly linked to dialysis adequacy, varies greatly around the world, with Japan having the best survival rates. Until the development of better markers of dialysis adequacy, universal consistency in reporting of conventional parameters with a focus on patient-reported measures should be endeavored.

Pattern of Laboratory Parameters and Management of Secondary Hyperparathyroidism in Countries of Europe, Asia, the Middle East, and North America

INTRODUCTION

This analysis explored laboratory mineral and bone disorder parameters and management of secondary hyperparathyroidism in patients undergoing hemodialysis in Belgium, Canada, China, France, Germany, Italy, Japan, Russia, Saudi Arabia, Spain, Sweden, the UK, and the USA.

METHODS

Analyses used demographic, medication, and laboratory data collected in the prospective Dialysis Outcomes and Practice Patterns Study (2012-2015). The analysis included 20,612 patients in 543 facilities. Descriptive data are presented as regional mean (standard deviation), median (interquartile range), or prevalence, weighted for facility sampling fraction. No testing of statistical hypotheses was conducted.

RESULTS

The frequency of serum intact parathyroid hormone levels > 600 pg/mL was lowest in Japan (1%) and highest in Russia (30%) and Saudi Arabia (27%). The frequency of serum phosphorus levels > 7.0 mg/dL was lowest in France (4%), the UK (6%), and Spain (6%), and highest in China (27%). The frequency of serum calcium levels > 10.0 mg/dL was highest in the UK (14%) and China (13%) versus 2% to 9% elsewhere. Dialysate calcium concentrations of 2.5 mEq/mL were common in the USA (78%) and Canada (71%); concentrations of 3.0-3.5 mEq/L were almost universal at facilities in Italy, France, and Saudi Arabia (each ≥ 99%).

CONCLUSIONS

Wide international variation in mineral and bone disorder laboratory parameters and management practices related to secondary hyperparathyroidism suggests opportunities for optimizing care.

Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions

In hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures. In emergency situations and especially in elderly with narrow and atherosclerotic vessels, a cuffed double-lumen catheter is placed in a larger vein for chronic use. The latter option constitutes a greater risk for infections while arteriovenous fistula and arteriovenous shunt can fail due to stenosis, thrombosis, or infections. This review will recapitulate the vast and interdisciplinary scenario that characterizes hemodialysis vascular access creation and function, since adequate access management must be based on knowledge of the state of the art and on future perspectives. We also discuss recent developments to improve arteriovenous fistula creation and patency, the blood compatibility of arteriovenous shunt, needs to avoid infections, and potential development of tissue engineering applications in hemodialysis vascular access. The ultimate goal is to spread more knowledge in a critical area of medicine that is importantly affecting medical costs of renal replacement therapies and patients’ quality of life.

Will you give my kidney back? Organ restitution in living-related kidney transplantation: ethical analyses

In this article, we perform a thought experiment about living donor kidney transplantation. If a living kidney donor becomes in need of renal replacement treatment due to dysfunction of the remaining kidney after donation, can the donor ask the recipient to give back the kidney that had been donated? We call this problem organ restitution and discussed it from the ethical viewpoint. Living organ transplantation is a kind of 'designated donation' and subsequently has a contract-like character. First, assuming a case in which original donor (A) wishes the return of the organ which had been transplanted into B, and the original recipient (B) agrees, organ restitution will be permissible based on contract-like agreement. However, careful and detailed consideration is necessary to determine whether this leaves no room to question the authenticity of B's consent. Second, if B offers to give back the organ to A, then B's act is a supererogatory act, and is praiseworthy and meritorious. Such an offer is a matter of virtue, not obligation. Third, if A wishes B to return the organ, but B does not wish/allow this to happen, it is likely difficult to justify returning the organ to A by violating B's right to bodily integrity. But B's refusal to return the donated organ cannot be deemed praiseworthy, because B forgets the great kindness once received from A. Rather than calling this an obligation, we encourage B to consider such virtuous conduct.

Real-world treatment patterns of renal anemia in hemodialysis patients: A multicenter cohort study performed using DialysisNet (RRAHD study)

A multicenter cohort study.The DialysisNet was previously developed for the management of hemodialysis (HD) patients based on the American Society for Testing and Materials Continuity of Care Records by metadata transformation. DialysisNet is a dialysis patient management program created by using the personal health record care platform to overcome the problems of registry studies, in real-time.Here, we aimed to investigate the pattern of treatment for renal anemia in HD patients using DialysisNet.We performed a multicenter cohort study among HD patients who were treated at one of the three Korean university-affiliated hospitals from January 2016 to December 2016. Subjects were divided into 4 hemoglobin variability groups by quartiles. The variable anemia treatment pattern was reviewed. To determine renal anemia treatment patterns, we automatically collected information on the practice of anemia treatment patterns such as erythropoietin stimulating agent (ESA) doses and administration frequencies, and targeted hemoglobin maintenance rate. Individual hemoglobin variabilities were expressed as (standard deviations)/(√(n/[n-1]).The records of 159 patients were analyzed (Hospital A: 35, Hospital B: 21, Hospital C: 103). Mean patients' age was 65.6 ± 12.8 years, and 61.6% were men. Overall, hemoglobin level was 10.5[7.43;13.93] g/dL. 158 (99.3%) patients were using ESA; and overall, the epoetin alfa dose was 33,000[4000;136,800] U per week. Hemoglobin levels (P = .206) and epoetin alfa doses were similar (P = .924) for patients with different hemoglobin variabilities. The hemoglobin target maintenance rate was lower in the highest hemoglobin variability group than in the lowest variability group (P = .045).In this study, detailed information on the actual anemia treatment patterns were obtained using the DialysisNet. We expect that DialysisNet will simplify and improve the renal anemia management for both dialysis patients and health care providers.

Risk of Complications and Survival of Patients Dialyzed with Permanent Catheters

Background and Objectives: An increase in the incidence of end-stage renal disease (ESRD) is associated with the need for a wider use of vascular access. Although arteriovenous (A-V) fistula is a preferred form of vascular access, for various reasons, permanent catheters are implanted in many patients. Materials and Methods: A retrospective analysis of clinical data was carried out in 398 patients (204 women) who in 2010-2016 were subjected to permanent dialysis catheters implantation as first vascular access or following A-V fistula dysfunction. The factors influencing the risk of complications related to vascular access and mortality were evaluated and the comparison of the group of patients with permanent catheter implantation after A-V fistula dysfunction with patients with first-time catheter implantation was carried out. Results: The population of 398 people with ESRD with mean age of 68.73 ± 13.26 years had a total of 495 permanent catheters implanted. In 129 (32.6%) patients, catheters were implanted after dysfunction of a previously formed dialysis fistula. An upward trend was recorded in the number of permanent catheters implanted in relation to A-V fistulas. Ninety-two infectious complications (23.1%) occurred in the study population in 65 patients (16.3%). Multivariate analysis showed that permanent catheters were more often used as the first vascular access option in elderly patients and cancer patients. Mortality in the mean 1.38 ± 1.17 years (min 0.0, max 6.70 years) follow-up period amounted to 50%. Older age and atherosclerosis were the main risk factors for mortality. Patients with dialysis fistula formed before the catheter implantation had a longer lifetime compared to the group in which the catheter was the first access. Conclusion: The use of permanent catheters for dialysis therapy is associated with a relatively high incidence of complications and low long-term survival. The main factors determining long-term survival were age and atherosclerosis. Better prognosis was demonstrated in patients after the use of A-V fistula as the first vascular access option.

Effect of statin on life prognosis in Japanese patients undergoing hemodialysis

The effect of statin on hemodialysis patients is controversial. Although previous large-scale studies did not clarify its effect in this population, recent studies suggest that statins could be useful in reducing the risk of cardiovascular events and all-cause mortality in specific groups of patients undergoing hemodialysis. The aforementioned large-scale studies included a small percentage of Asians, and few studies have investigated the effects of statins in Asians undergoing hemodialysis. Thus, we investigated the benefits of statins in patients undergoing maintenance hemodialysis at a single center in Japan. We obtained demographic, clinical, and hemodialysis data of all patients who underwent maintenance hemodialysis at the Nagasaki Renal Center between July 2011 and June 2012. Patients were followed-up until June 2018. We studied 339 patients, of which 51 (15.0%) were prescribed pitavastatin. The mean observation period was 4.1±2.3 years, 43% were women, and the median hemodialysis vintage at baseline was 4.7 years. During the follow-up, 198 patients (58%) died, of which 22 (43%) were prescribed pitavastatin and 176 (61%) were not prescribed any statins. After propensity score matching based on age, sex, dialysis vintage, dialysis time, diabetes mellitus, ischemic heart disease, dry weight, left ventricular ejection fraction, and serum albumin, an intergroup comparison between those who received statins and those who did not (44 patients in each group) showed significant differences in survival rate based on the log-rank test (P<0.05). Although the causes of death did not differ significantly between groups, deaths due to cardiovascular events, infections, and cancer were fewer in the group prescribed statins. Our results suggest that statins may reduce mortality in Japanese patients undergoing maintenance hemodialysis. Although potential residual confounders exist, statins may have an influence on the reduction in the incidence of cardiovascular events, infections, and cancer. Nevertheless, further studies are required to prove this hypothesis.

Penalized survival models for the analysis of alternating recurrent event data

Recurrent event data are widely encountered in clinical and observational studies. Most methods for recurrent events treat the outcome as a point process and, as such, neglect any associated event duration. This generally leads to a less informative and potentially biased analysis. We propose a joint model for the recurrent event rate (of incidence) and duration. The two processes are linked through a bivariate normal frailty. For example, when the event is hospitalization, we can treat the time to admission and length-of-stay as two alternating recurrent events. In our method, the regression parameters are estimated through a penalized partial likelihood, and the variance-covariance matrix of the frailty is estimated through a recursive estimating formula. Moreover, we develop a likelihood ratio test to assess the dependence between the incidence and duration processes. Simulation results demonstrate that our method provides accurate parameter estimation, with a relatively fast computation time. We illustrate the methods through an analysis of hospitalizations among end-stage renal disease patients.

Angiography and phlebography in a hemodialysis population: A retrospective analysis of interventional results

OBJECTIVE

To clarify the reasons and beneficial effects and duration of arteriovenous fistula patency after radiological interventions in arteriovenous fistula. The patients investigated were referred due to arteriovenous fistula access flow problems.

MATERIAL AND METHODS

In 174 patients, 522 radiological investigations and endovascular treatments such as percutaneous transluminal angioplasty were analyzed, retrospectively. All investigations were performed due to clinical suspicion of impaired arteriovenous fistula function.

RESULTS

Arterial stenosis was significantly more frequent among patients with diabetic nephropathy (p < 0.001) and interstitial nephritis (p < 0.001). According to the venous stenosis, the diagnosis did not affect the frequency (p = 0.22) or the degree (p = 0.39) of stenosis. The degree of stenosis prior to percutaneous transluminal angioplasty correlated significantly with the degree of remaining stenosis after intervention (p < 0.001). Of the 174 patients, 123 (71%) performed a total of 318 investigations including percutaneous transluminal angioplasty. Repeated percutaneous transluminal angioplasty was performed significantly more often in patients with diabetic nephropathy. The median times to the first percutaneous transluminal angioplasty and to the subsequent percutaneous transluminal angioplasties were 9.5 and 5 months, respectively. Arteriovenous fistula in patients with diabetic nephropathy performed similar to most other diagnoses, although performing more percutaneous transluminal angioplasty/patient than most other diagnoses.

CONCLUSION

Many patients could maintain long-term patency of arteriovenous fistula, including those with diabetic nephropathy, with repeated interventions; this motivates a closer follow-up for these patients. Clinically significant stenosis should be dilated as meticulously and as soon as possible. Occlusions of the arteriovenous fistula in most instances can be successfully thrombolyzed or dilated upon early diagnosis.

Current state of dialysis treatment and vascular access management in Japan

According to the data from the Japanese Society for Dialysis Therapy, the number of dialysis patients was about 330,000 at the end of 2016. The mean age of newly initiated patients was 69.4 years and that of maintenance was 68.2 years. And, diabetic nephropathy is the most common primary disease, with an incidence rate of 43.2%. These results mean that the systemic vascular condition is getting worse. In spite of these backgrounds, the patients of 97.3% were treated by hemodialysis; therefore, careful management of vascular access is essential to better maintain the condition of patients. The Dialysis Outcomes and Practice Patterns Study shows that vascular access modalities are an important factor in determining prognoses of patients and that prognosis in Japan is one of the best worldwide. In Japan, the use of arteriovenous fistulae accounts for 95% of vascular access modalities. However, a statistic by Japanese Society for Dialysis Therapy suggests that the use of arteriovenous graft has been increasing. In 2005, Japanese Society for Dialysis Therapy Guidelines recommended percutaneous transluminal angioplasty be the first choice for the treatment of vascular access stenosis. Since then, percutaneous transluminal angioplasty has become an important procedure for long-term maintenance of the morphology and function of vascular access. In Japan, approximately 60% of percutaneous transluminal angioplasty are conducted by nephrologists and urologists; in addition, arteriovenous fistulae creation procedures are also performed by them. According to my private opinion, such conditions above show that even in the absence of standardized training on vascular access management, doctors on site perform their duties in an appropriate manner. However, the problems of how we evaluate the specificity in Japan and pass it down the generations still remain.

The Potential Impact of Public Health Interventions in Preventing Kidney Disease

The years of life lost and years lived with disability resulting from chronic kidney disease (CKD) increased globally by 90% and 49.5%, respectively, between 1990 and 2013. In addition to the traditional factors, infections, low birthweight, environmental factors, and low socioeconomic status contribute to the CKD burden in low- and middle-income countries. System-level challenges such as poor appreciation of the burden, insufficient human resources, high health care costs, poor referral pathways, unreliable health information systems, and inadequate medicine supply pose barriers to CKD control. In this article, we present evidence that the CKD burden in low- and middle-income countries is related to system-wide issues, which could be reduced effectively using innovative, affordable, and scalable interventions. A multipronged approach is required including improving socioeconomic determinants of health, enabling the environment for healthy decision making, and sustainable interventions. Innovative approaches include promoting healthy behaviors, counseling, and education in primary care, task-sharing between physicians and nonphysicians, using technology to train nonphysicians to screen, diagnose, refer, follow-up, and educate patients, and ensuring quality. Stronger political will and system-level change are needed to prevent and manage CKD if the sustainable development goals of reducing premature mortality from noncommunicable diseases by 2030 are to be attained.

A C-index for recurrent event data: Application to hospitalizations among dialysis patients

We propose a C-index (index of concordance) applicable to recurrent event data. The present work addresses the dearth of measures for quantifying a regression model's ability to discriminate with respect to recurrent event risk. The data which motivated the methods arise from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a long-running prospective international study of end-stage renal disease patients on hemodialysis. We derive the theoretical properties of the measure under the proportional rates model (Lin et al., 2000), and propose computationally convenient inference procedures based on perturbed influence functions. The methods are shown through simulations to perform well in moderate samples. Analysis of hospitalizations among a cohort of DOPPS patients reveals substantial improvement in discrimination upon adding country indicators to a model already containing basic clinical and demographic covariates, and further improvement upon adding a relatively large set of comorbidity indicators.

Effects of weight-based ultrafiltration rate limits on intradialytic hypotension in hemodialysis

INTRODUCTION

High ultrafiltration (UF) rates can result in intradialytic hypotension and are associated with increased mortality. The effects of a weight-based UF rate limit on intradialytic hypotension and the potential for unwanted fluid weight gain and hospitalizations for volume overload are unknown.

METHODS

This retrospective cohort study examined 123 in-center hemodialysis patients at one facility who transitioned to 13 mL/kg/h maximum UF rates. Patients were studied for an 8 week UF rate limit exposure period and compared to the 8-week period immediately prior, during which the cohort served as its own historical control. The primary outcomes were frequency of intradialytic hypotension events and percentage of treatments with a hypotension event.

FINDINGS

The delivered UF rate was lower during the exposure compared to the baseline period (mean UF rate 7.90 ± 4.45 mL/kg/h vs. 8.92 ± 5.64 mL/kg/h; P = 0.0005). The risk of intradialytic hypotension was decreased during the exposure compared to baseline period (event rate per treatment 0.0569 vs. 0.0719, OR 0.78 [95% CI 0.62-1.00]; P = 0.0474), as was the risk of having a treatment with a hypotension event (percentage of treatments with event 5.2% vs. 6.8%, OR 0.75 [95% CI 0.58-0.96]; P = 0.0217). Subgroup analyses demonstrated that these findings were attributable to patients with high baseline UF rates. Statistically significant differences in all-cause or volume overload-related hospitalization were not observed during the exposure period.

DISCUSSION

A weight-based UF rate limit of 13 mL/kg/h was associated with a decrease in the rate of intradialytic hypotension events among in-center hemodialysis patients.

Initial Session Duration and Mortality Among Incident Hemodialysis Patients

BACKGROUND

The association of dialysis session duration with mortality in patients undergoing maintenance hemodialysis is unclear. We compared mortality rates of patients treated in dialysis facilities that used initial session durations of either ≥ 4 versus 3 hours for all incident patients.

STUDY DESIGN

Retrospective cohort study.

SETTINGS & PARTICIPANTS

Patients with end-stage renal disease beginning maintenance hemodialysis therapy in January 2006 to December 2010 and followed up through December 2012, including 39,172 patients in 852 facilities who initiated treatment for ≥ 4 hours and 47,721 patients in 631 facilities who initiated treatment for 3 hours.

PREDICTOR

Initial session duration of ≥ 4 hours versus 3 hours.

OUTCOME

2- and 1-year mortality rates.

RESULTS

Total numbers of deaths observed within 2 years after initiating dialysis therapy were 8,945 in the ≥ 4-hour group and 15,624 in the 3-hour group. The corresponding numbers of deaths observed within 1 year were 5,492 and 10,372, respectively. The 2-year adjusted HR in the ≥ 4-hour versus 3-hour group was 0.79 (95% CI, 0.73-0.86). The corresponding 1-year adjusted HR was 0.77 (95% CI, 0.70-0.84). Results were robust when analyses were restricted to specific subgroups of patients classified by age, sex, race, and select clinical characteristics.

LIMITATIONS

We did not observe hemodialysis duration in sessions subsequent to initiation. We only included patients treated in facilities with uniform session length (at initiation) for all their patients. Furthermore, we lacked information for dialysis dosage and patients' baseline residual kidney function.

CONCLUSIONS

Patients in facilities routinely initiating hemodialysis therapy for ≥ 4 hours may have substantially lower mortality as compared with patients in facilities initiating for only 3 hours of treatment.