Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

A Simple Exercise Program for Patients With End-Stage Kidney Disease to Improve Strength and Quality of Life: Clinical Research Protocol

Background

Most patients with end-stage kidney disease (ESKD) appreciate the importance of exercise and would like to increase their physical activity; however, they report a few key barriers, including (1) lack of physician advice to do so, (2) lack of safe and convenient programs (ie, appropriate for home or neighborhood), and (3) cost. Importantly, patients indicated in a previous survey that they would prefer an exercise program that improves muscle strength and symptoms, and are less interested in cardiovascular disease prevention.

Objective

To test the feasibility of a simple, prescribed exercise program using Nordic walking poles in patients with ESKD treated with dialysis.

Design

Randomized multicenter pilot trial of an exercise intervention that includes Nordic walking poles, personalized physician exercise prescriptions, pedometers, and access to exercise videos, compared with standard of care, in patients being treated with maintenance dialysis.

Setting

Multicenter tertiary care centers in Canada.

Patients

Ambulatory adult patients with ESKD treated with peritoneal dialysis or hemodialysis (HD) for at least 6 months at participating sites are potentially eligible. Inclusion criteria include ability to use Nordic walking poles (either de novo or in place of mobility aid) and to provide informed consent in English or in French. Exclusion criteria include (1) any absolute contraindication to exercise, (2) baseline step count >8000 steps/day, (3) planned living donor kidney transplant, and (4) participation in another interventional trial that may affect the results of this study.

Methods

This is a randomized multicenter pilot trial of an exercise intervention that consists of a prescription to exercise using Nordic walking poles, a pedometer to track activity, and access to exercise videos, with the comparator of standard of care (dialysis unit staff encouragement to exercise) in patients being treated with maintenance dialysis. Randomization is concealed and uses a 1:1 ratio for group assignment. Our specific aims are to determine the feasibility of patient recruitment, adherence to the exercise program (verified by step counts), and efficacy of the intervention on patient-important outcomes that were assessed as a priority by patients in a prior survey-specifically strength, fatigue, and sleep. We record days spent in hospital and loss of independent living to inform sample size calculations for a definitive trial of exercise in patient with ESKD treated with dialysis. Adverse events are closely monitored.

Outcomes

Primary: Our recruitment goal is 90 to 150 patients over 27 months; adherence success will be defined if >75% of randomized patients, excluding those who are transplanted or deceased, achieve >80% of their prescribed steps at 6 and 12 months. Secondary Efficacy Outcomes: (1) strength-hand grip strength and 5 times sit to stand, (2) energy-Short Form (SF)-36 vitality subscale, and (3) sleep-Pittsburg Sleep Quality Index will be assessed at baseline, 6, and 12 months.

Results

Trial recruitment started before the COVID-19 pandemic and the pandemic led to many interruptions and delays. Online exercise Web sites and a tailored video were added to the protocol to encourage activity when participants were unable or reluctant to walk in public places.

Limitations

This trial was designed to include ambulatory patients with ESKD and does not address the burden of disease in patients with very restricted mobility.

Trial Registration

NCT03787589.

Cardiac implications of upper-arm arteriovenous fistulas: A case series

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in patients with end-stage kidney disease. Arterio-venous fistulas (AVF), the gold standard for hemodialysis vascular access, are known to alter cardiac morphology and circulatory hemodynamics. We present a prospective case series of patients after creation of an AVF, explore the timeline for changes in their cardiac morphology, and detail considerations for clinicians.

METHODS

Patients were recruited in 2010 at multiple centers immediately prior to the creation of an upper-arm AVF and the initiation of hemodialysis. Cardiovascular magnetic resonance images were taken at intake before the creation of the AVF, 6-month follow-up, and 12-month follow-up. Image segmentation was used to measure left ventricular volume and mass, left atrial volume, and ejection fraction.

RESULTS

Eight patients met eligibility criteria. All eight patients had a net increase in left ventricular mass over enrollment, with a mean increase of 9.16 g (+2.96 to +42.66 g). Five participants had a net decrease in ejection fraction, with a mean change in ejection fraction of -5.4% (-21% to +5%). Upon visual inspection the patients with the largest ejection fraction decrease had noticeably hypertrophic and dilated ventricles. Left atrial volume change was varied, decreasing in five participants, while increasing in three participants. Changes in morphology were present at 6-month follow-up, even in patients who did not maintain AVF patency for the entirety of the 6-month period.

CONCLUSION

All patients included in this prospective case series had increases in left ventricular mass, with variability in the effects on the ejection fraction and left atrial volume. As left ventricular mass is an independent predictor of morbidity and mortality, further research to determine appropriate vascular access management in both end-stage kidney disease and kidney transplant populations is warranted.

North American Weight Management Programs for People Living With Chronic Kidney Disease: An Environmental Scan

Background

The availability and accessibility of patient-centered weight management programs is critical to mitigate the increasing prevalence of obesity in people living with chronic kidney disease (CKD). Little is known about the availability of contemporary programs that can safely and effectively support individuals living with obesity and CKD across North America.

Objective

We sought to identify weight management programs specific to those with CKD and explore their safety, affordability, and adaptability to this patient population. We also identified the barriers and facilitators of identified programming including their accessibility to real-world patients (eg, cost, access, support, and time).

Design

Environmental scan of weight management programs.

Setting

North America.

Patient

People living with CKD.

Methods

We identified weight management programs and associated barriers and facilitators, via an Internet-based search of commercial, community-based, and medically supervised weight management programming. We also conducted a gray literature search and contacted weight management experts and program facilitators to explore strategies as well as their barriers and facilitators.

Results

We identified 40 weight management programs available to people living with CKD across North America. Programs were commercial (n = 7), community-based (n = 9), and medically supervised (Canada n = 13, U.S n = 8) in origin. Three programs were specifically tailored to CKD (n = 3). In addition to formal programs, we also identified online nutritional resources and guidelines for weight loss in CKD (n = 8), and additional strategies (self-management tools, group orientated programs, moderate energy restrictions in conjunction with exercise and Orlistat) for weight loss from the gray literature (n = 3). Most common barriers were difficulty accessing some of the suggested nutritious food options due to the high cost, lack of support from family, friends and health practitioners, the time commitment required to participate, and the exclusion from weight management programs due to unique dietary needs for the CKD population. Most common facilitators were programs that were patient-centered, evidence-based, and offered both group and individual formats.

Limitations

Although our search criteria were broad, it is possible that we did not capture all weight management programs available across North America.

Conclusions

This environmental scan has generated a resource list of existing safe and effective programs for or adaptable to people with CKD. This information will inform future efforts to develop and deliver CKD-specific weight management programs to patients living with comorbid disease. Engaging people living with CKD to understand the acceptability of these programs, is an important focus for future research.

Glucagon-like peptide 1 receptor agonists in end-staged kidney disease and kidney transplantation: A narrative review

AIMS

Glucagon-like peptide 1 receptor agonists (GLP-1RA) improve glycemic control and promote weight loss in type 2 diabetes (DM2) and obesity. We identified studies describing the metabolic benefits of GLP-1RA in end-staged kidney disease (ESKD) and kidney transplantation.

DATA SYNTHESIS

We searched for randomized controlled trials (RCTs) and observational studies that investigated the metabolic benefits of GLP-1RA in ESKD and kidney transplantation. We summarized the effect of GLP-1RA on measures of obesity and glycemic control, examined adverse events, and explored adherence with therapy. In small RCTs of patients with DM2 on dialysis, liraglutide for up to 12 weeks lowered HbA1c by 0.8%, reduced time in hyperglycemia by ∼2%, lowered blood glucose by 2 mmol/L and reduced weight by 1-2 kg, compared with placebo. In prospective studies inclusive of ESKD, 12 months of semaglutide reduced HbA1c by 0.8%, and contributed to weight losses of 8 kg. In retrospective cohort studies in DM2 and kidney transplantation, 12 months of GLP-1RA lowered HbA1c by 2%, and fasting glucose by ∼3 mmol/L compared with non-use, and in some reports, weight losses of up to 4 kg were described. Gastrointestinal (GI) side effects were most commonly reported, with hypoglycemia described with GLP-1RA in hemodialysis, particularly in those using insulin.

CONCLUSIONS

GLP-1RA are growing in popularity in those with DM2 and obesity. In small RCTs and observational cohort studies modest glycemic and weight benefits have been described in ESKD and transplantation, but GI side effects may limit adherence. Larger and longer term studies of GLP-1RA remain important.

Management of Type 2 Diabetic Kidney Disease in 2022: A Narrative Review for Specialists and Primary Care

Purpose of review

Kidney disease is present in almost half of Canadian patients with type 2 diabetes (T2D), and it is also the most common first cardiorenal manifestation of T2D. Despite clear guidelines for testing, opportunities are being missed to identify kidney diseases, and many Canadians are therefore not receiving the best available treatments. This has become even more important given recent clinical trials demonstrating improvements in both kidney and cardiovascular (CV) endpoints with sodium-glucose cotransporter 2 (SGLT2) inhibitors and a nonsteroidal mineralocorticoid receptor antagonist, finerenone. The goal of this document is to provide a narrative review of the current evidence for the treatment of diabetic kidney disease (DKD) that supports this new standard of care and to provide practice points.

Sources of information

An expert panel of Canadian clinicians was assembled, including 9 nephrologists, an endocrinologist, and a primary care practitioner. The information the authors used for this review consisted of published clinical trials and guidelines, selected by the authors based on their assessment of their relevance to the questions being answered.

Methods

Panelists met virtually to discuss potential questions to be answered in the review and agreed on 10 key questions. Two panel members volunteered as co-leads to write the summaries and practice points for each of the identified questions. Summaries and practice points were distributed to the entire author list by email. Through 2 rounds of online voting, a second virtual meeting, and subsequent email correspondence, the authors reached consensus on the contents of the review, including all the practice points.

Key findings

It is critical that DKD be identified as early as possible in the course of the disease to optimally prevent disease progression and associated complications. Patients with diabetes should be routinely screened for DKD with assessments of both urinary albumin and kidney function. Treatment decisions should be individualized based on the risks and benefits, patients' needs and preferences, medication access and cost, and the degree of glucose lowering needed. Patients with DKD should be treated to achieve targets for A1C and blood pressure. Renin-angiotensin-aldosterone system blockade and treatment with SGLT2 inhibitors are also key components of the standard of care to reduce the risk of kidney and CV events for these patients. Finerenone should also be considered to further reduce the risk of CV events and chronic kidney disease progression. Education of patients with diabetes prescribed SGLT2 inhibitors and/or finerenone is an important component of treatment.

Limitations

No formal guideline process was used. The practice points are not graded and are not intended to be viewed as having the weight of a clinical practice guideline or formal consensus statement. However, most practice points are well aligned with current clinical practice guidelines.

A New Perspective to Longstanding Challenges with Outpatient Hyperkalemia: A Narrative Review

Purpose of Review

Outpatient hyperkalemia is a common problem with potentially deadly consequences. Potassium level thresholds to treat outpatient hyperkalemia are unstandardized and variable, leaving health care providers to rely on their own clinical judgment. This narrative review highlights the challenges of outpatient hyperkalemia management and includes recommendations for future studies that may standardize treatment, improve patient outcomes, and optimize health care utilization.

Sources of Information

PubMed, Google Scholar, and the reference lists of identified articles were used to include English, peer-reviewed studies and guidelines for this review.

Methods

This narrative review examines outpatient hyperkalemia from both a laboratory and clinical perspective. In addition to peer-reviewed literature, guidelines and expert consensus statements were included to highlight the inconsistencies and paucity of evidence that health care providers rely on to make clinical decisions.

Key Findings

There are multiple reasons why outpatient hyperkalemia management is both challenging and sub-optimal. Clinicians must discern if the potassium level result is accurate and, if so, does the result warrant referral to the emergency department. Factitious hyperkalemia, or falsely elevated potassium level results due to analytical errors, occurs frequently, but there are no ways to identify it other than for hemolyzed samples. Additionally, guidelines and expert panels are inconsistent on the thresholds for treatment and the management of hyperkalemia. Finally, there are inconsistencies between laboratories as to when and how providers are notified of results, and the suggested thresholds for urgent management. A study that integrates the expertise of clinical biochemists and clinicians is needed to inform evidence-based guidelines for the management of outpatient hyperkalemia.

Limitations

This was a comprehensive review of what is known and what still needs to be understood for the management of outpatient hyperkalemia. A formal tool to assess the quality of the included studies was not used and selection bias may have occurred.

Improving Timeliness in Surgical Discharge Summary Distribution: A Quality Improvement Initiative

Objective

To implement a quality improvement initiative to achieve an institutional targeted discharge summary distribution metric of 50% within 48 hours of patient discharge from hospital within an academic tertiary care otolaryngology–head and neck surgery department.

Methods

A pre- and postintervention study was conducted. Process mapping was performed. Interventions included education and engagement, implementation of auto-authentication (distribution immediately following transcription without review by the most responsible physician), and audit and feedback. The percentage of discharge summaries dictated with the auto-authentication code was evaluated. Process measures were collected for 12 months pre- and postimplementation. Balancing measures included workload and revisions to auto-authenticated notes. Analysis included summary statistics, statistical process control charting, and unpaired t tests.

Results

The mean ± SD percentage of discharge summaries distributed within 48 hours increased from 19% ± 6.4% preintervention to 54% ± 20% postintervention (P < .0001). Seventy-four percent of discharge summaries were dictated via the auto-authentication code. The target metric was met in 71% of discharges with the auto-authentication codes as compared with 26% with non–auto-authentication. The interventions did not result in any change to perceived workload, and the incidence of auto-authentication revisions was <1%. The results were sustained with an increase of 72% the following quarter. For fiscal year 2021-2022, performance remained sustained with an 85% completion rate.

Discussion

Our surgical department exceeded and sustained the targeted metric for timely discharge summary distribution using a quality improvement approach.

Implications for Practice

Timely distribution of discharge summaries optimizes patients’ transitions of care and can be achieved through stakeholder education and engagement, auto-authentication, and audit with feedback.

Recognition of Obesity and Perceptions of Weight Loss Management in Patients With Chronic Kidney Disease: A Retrospective Cross-Sectional Study

Background:

Obesity is, directly and indirectly, linked to the progression of chronic kidney disease (CKD). However, nephrologists’ recognition of obesity and willingness to address and manage obesity are unknown.

Objectives:

The aim of this article is to investigate if obesity is recognized and documented in the clinical encounter and to examine nephrologists’ perceptions of obesity and comfort with weight loss management.

Design:

We conducted a 2-part study. Part I used a retrospective chart review and part II used an anonymous online survey of practicing nephrologists (n = 14) in our center.

Setting:

The study took place in the Multi-care Kidney Clinic (MCKC) at London Health Sciences Centre in London, Ontario, Canada.

Patients:

In part I, we conducted a retrospective chart review of 10 random patients with advanced CKD and obesity (body mass index [BMI] > 30 kg/m²) from each of the nephrologists between January and December 2019.

Methods:

In part I, charts were assessed for documentation of obesity and/or a treatment plan (lifestyle counseling, pharmacologic intervention, and specialist referral). In part II, a survey completed by the nephrologists explored their current experience and perceptions of obesity and comfort with weight loss management. Responses were ranked on a 5-point Likert scale.

Results:

In all, 140 patient charts were reviewed. The median age was 69 (interquartile range [IQR] = 60-77) years, estimated glomerular filtration rate (eGFR) was 17 (IQR = 12-20) ml/min/1.73 m², weight was 99 (IQR = 90-116) kg, and BMI was 36 (IQR = 33-40) kg/m². Obesity with a BMI was documented in 36 (26%) charts, and only 2 (1%) documented a weight loss plan, which only included non-pharmacologic strategies. There were 13 survey responses (93% response rate). All nephrologists agreed that obesity negatively affects the health of patients with CKD. Twelve (92%) reported discussing obesity with patients, but none felt that they had time to treat it. All reported discussions of obesity would evoke a negative patient response, while 5 (38%) thought patients actually want to discuss obesity. Regarding treatment, 8 (62%) nephrologists felt comfortable with non-pharmacologic treatment, but only 1 respondent was comfortable with pharmacologic treatments. Twelve (92%) nephrologists thought patients should be referred to a specialist.

Limitations:

There was limited generalizability as this was a single center study. The BMI may reflect hypervolemia rather than body mass.

Conclusion:

In our study, nephrologists rarely document and manage obesity in patients with advanced CKD, despite their perception of treatment benefits. Improved outcomes of obesity management for patients with CKD will require increased knowledge and clinical tools to efficiently address obesity with patients.

Community engagement in kidney research: Guatemalan experience

Background

Community engagement is essential for effective research when addressing issues important to both the community and researchers. Despite its effectiveness, there is limited published evidence concerning the evaluation of community engagement in research projects, especially in the area of nephrology.

Methods

We developed a community engagement program in Guatemala to address the role of hydration in chronic kidney disease of unknown origin, using five key engagement principles: 1. Local relevance and determinants of health. 2. Acknowledgment of the community. 3. Dissemination of findings and knowledge gained to all partners. 4. Usage of community partners’ input. 5. Involvement of a cyclical and iterative process in the pursuit of goals. The effectiveness of community engagement was measured by a structured questionnaire on a 5-point likert scale. This measure determined how well and how often the research team adhered to the five engagement principles. We assessed internal consistency for each set of the engagement items through Omega coefficient.

Results

Sixty-two community leaders completed the questionnaire. Seventy-five percent were female, with a mean age of 37 years. All 5 engagement principles scored highly on the 5-point likert scale. Every item set corresponding to an engagement principles evaluation had a Omega coefficient > 0.80, indicating a firm internal consistency for all question groups on both qualitative and quantitative scales.

Conclusion

Engagement of the community in the kidney research provides sustainability of the efforts and facilitates the achievements of the goals. Community leaders and researchers became a team and develop a relationship in which commitment and empowerment facilitated the participation in all aspects of the research process. This initiative could be a useful tool for researchers, especially in low-middle income countries, to start research in a community, achieve objectives in a viable form, and open opportunities to further studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02891-8.

Inhibit progression of coronary artery calcification with vitamin K in hemodialysis patients (the iPACK-HD study): a randomized, placebo-controlled multi-center, pilot trial

BACKGROUND

Vitamin K activates matrix Gla protein (MGP), a key inhibitor of vascular calcification. There is a high prevalence of sub-clinical vitamin K deficiency in patients with end-stage kidney disease.

METHODS

A parallel randomized placebo-controlled pilot trial was designed to determine whether 10 mg of phylloquinone thrice weekly versus placebo modifies coronary artery calcification progression over 12 months in patients requiring hemodialysis with a coronary artery calcium score (CAC) ≥30 Agatston Units (ClinicalTrials.gov identifier NCT01528800). The primary outcome was feasibility (recruitment rate, compliance with study medication, study completion and adherence overall to study protocol). CAC score was used to assess calcification at baseline and 12 months. Secondary objectives were to explore the impact of phylloquinone on vitamin K-related biomarkers (phylloquinone, dephospho-uncarboxylated MGP and the Gla-osteocalcin to Glu-osteocalcin ratio) and events of clinical interest.

RESULTS

A total of 86 patients with a CAC score ≥30 Agatston Units were randomized to either 10 mg of phylloquinone or a matching placebo three times per week. In all, 69 participants (80%) completed the trial. Recruitment rate (4.4 participants/month) and medication compliance (96%) met pre-defined feasibility criteria of ≥4.17 and ≥90%, respectively. Patients randomized to phylloquinone for 12 months had significantly reduced levels of dephospho-uncarboxylated MGP (86% reduction) and increased levels of phylloquinone and Gla-osteocalcin to Glu-osteocalcin ratio compared with placebo. There was no difference in the absolute or relative progression of coronary artery calcification between groups.

CONCLUSION

We demonstrated that phylloquinone treatment improves vitamin K status and that a fully powered randomized trial may be feasible.

PATENCY-2 trial of vonapanitase to promote radiocephalic fistula use for hemodialysis and secondary patency

OBJECTIVE

Arteriovenous fistulas created for hemodialysis often fail to become usable and are frequently abandoned. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in increasing radiocephalic fistula use for hemodialysis and secondary patency.

METHODS

PATENCY-2 was a randomized, double-blind, placebo-controlled trial in patients on or approaching the need for hemodialysis undergoing radiocephalic arteriovenous fistula creation. Of 696 screened, 613 were randomized, and 603 were treated (vonapanitase n = 405, placebo n = 208). The study drug solution was applied topically to the artery and vein for 10 min immediately after fistula creation. The primary endpoints were fistula use for hemodialysis and secondary patency (fistula survival without abandonment). Other efficacy endpoints included unassisted fistula use for hemodialysis, primary unassisted patency, fistula maturation and unassisted maturation by ultrasound criteria, and fistula procedure rates.

RESULTS

The proportions of patients with fistula use for hemodialysis was similar between groups, 70% vonapanitase and 65% placebo, (p = 0.33). The Kaplan-Meier estimates of 12-month secondary patency were 78% (95% confidence interval [CI], 73-82) for vonapanitase and 76% (95% CI, 70-82) for placebo (p = 0.93). The proportions with unassisted fistula use for hemodialysis were 46% vonapanitase and 37% placebo (p = 0.054). The Kaplan-Meier estimates of 12-month primary unassisted patency were 50% (95% CI, 44-55) for vonapanitase and 43% (95% CI, 35-50) for placebo (p = 0.18). There were no differences in the proportion of patients with fistula maturation or in fistula procedure rates. Adverse events were similar between groups. Vonapanitase was not immunogenic.

CONCLUSIONS

Vonapanitase treatment did not achieve clinical or statistical significance to meaningfully improve radiocephalic fistula surgical outcomes. Outcome in the placebo group were better than in historical controls. Vonapanitase was well-tolerated and safe.

TRIAL REGISTRATION

clinicaltrials.gov: NCT02414841 (https://clinicaltrials.gov/ct2/show/NCT02414841).

Proceedings From a Canadian Nephrology Forum: Nephrology Is Back

PURPOSE OF CONFERENCE

On January 18, 2020, the Nephrology is Back learning day forum was held in Toronto, ON, Canada. The objectives of the meeting were to describe recent advances in nephrology for community and academic nephrologists and patients, and to define challenges and opportunities for integration of new data into clinical practice. The intent was to test a unique forum for continuing medical education integrating physician and patient experiences with the goal of encouraging change in practice.

SOURCES OF INFORMATION

Program content was based on current literature and clinical experience. Additional information was provided by patient partners who attended the meeting to provide their perspective on current issues in nephrology.

METHODS

A steering committee (A.L., A.S., and D.S.) developed goals and an outline for the content to be covered over the course of the meeting and led the recruitment of speakers. Speakers were asked to develop their presentations independently following direction by the committee, based on primary sources, including their own experiences. Presentations were followed by discussion including both physicians and patients, and participants had an opportunity to evaluate the conference and its outcomes.

KEY FINDINGS

We present a unique approach to providing continuing medical education by including both physicians and patients in the learning process. Patient perspectives accompanying presentations around data and other clinical topics provided a much different environment from other knowledge translation exercises. We believe this represents an innovative approach for knowledge translation that allows physicians to address clinical topics in a novel manner, including the integration of new findings into practice and the need to cascade this education to their peers.

LIMITATIONS

Because the conference was a one-time event, it has been difficult to assess the actual clinical impact of the knowledge translation exercise and whether physician behaviors have changed as a result of the activity. The conference could also have included broader representation from across Canada.

IMPLICATIONS

The success of this test forum among both physicians and patient partners suggests that the inclusion of patient partners in learning could have an important role in future educational initiatives.

P1283BASELINE CHARACTERISTICS IN THE “IPACK-HD” STUDY (INHIBIT PROGRESSION OF CORONARY ARTERY CALCIFICATION WITH VITAMIN K IN HEMODIALYSIS PATIENTS): A PHASE 2, MULTI-CENTRE, DOUBLE-BLIND, RANDOMIZED, PLACEBO-CONTROLLED PILOT TRIAL

Background and Aims

The leading cause of mortality for patients with end-stage kidney disease (ESKD) is cardiovascular disease (CVD). This is due, in part, to vascular calcification (VC) where calcium becomes deposited within arterial walls causing narrowing of the arteries and altering their flexibility. Matrix Gla protein (MGP), a vitamin k-dependent protein, is a key local inhibitor of VC and becomes up-regulated adjacent to sites of calcification. There is a very high prevalence of vitamin K deficiency in patients across the chronic kidney disease (CKD) spectrum and vitamin K has been shown to prevent VC in experimental models. To date, no trial has examined whether vitamin K supplementation prevents the progression of coronary artery calcification in patients with ESKD, a group in which high risk has been established. The aim of the iPACK-HD pilot study is to determine whether a trial to determine whether vitamin K has a favourable effect on coronary artery calcium (CAC) scores in patients with ESKD is feasible.

Method

The iPACK-HD pilot trial is a phase 2 multi-centre, double-blind, randomized, placebo-controlled clinical trial conducted in three sites (Kingston, Ottawa and London) in Ontario, Canada. Adult patients with ESKD on chronic dialysis with a baseline CAC score of ≥30 Agatston units (AUs) are randomized to receive 10 mg of vitamin K1 or matching placebo administered post-hemodialysis 3x/week for a total of 12 months. Exclusions include medical conditions that require anticoagulation and a history of either coronary artery bypass, grafting or stenting. Randomization is stratified based on diabetes and study centre. Baseline CAC scores are determined by computed tomography (CT) and demographic and laboratory data at study entry are obtained by participant interview and medical chart review.

Results

A total of 85 participants are randomized into this trial. Baseline characteristics of trial participants are reported as mean ± SD, median [IQR], or %. The mean age is 63 ± 13 years. There are a higher proportion of males (57%) than females and whites (85%) compared to all other ethnicities. Forty-four percent of participants have diabetes and 77% have hypertension. Dialysis vintage is 0.9 [0.4,2.7] years. Most participants take calcium-based phosphate binders (89%) and over half of participants take an HMG-CoA reductase inhibitor (53%) or vitamin D (61%). Clinical laboratory values are presented in Table 1. Total median CAC and volume calcium scores are 587 [252,1416] AUs and 482 [206,1170] mm3, respectively. Sixty-five (76%) participants had a study exit CT scan performed upon completion of the study. Of 156 doses, a median of 150 [123,155] were received and 2 [1,6] were missed.

Conclusion

Participants in the iPACK-HD study have a high burden of calcification but are similar in baseline characteristics to the Canadian hemodialysis population. Loss to trial completion is 24%, but the most frequent reason is kidney transplantation. Adherence to study drug is very high with few reported side effects.

KDOQI 2019 Vascular Access Guidelines: What Is New?

The new Kidney Disease Outcomes Quality Initiative Vascular Access Guidelines now focus on a more comprehensive overall patient strategy. The patient's vascular access needs are part of a dialysis access strategy, which itself is part of an End Stage Kidney Disease Life-Plan strategy that stems from a unique patient's individualized needs. The End Stage Kidney Disease Life-Plan is an individualized and comprehensive map for dialysis modalities and dialysis access for the lifetime of the patient. New targets are introduced that align with this patient-centered approach. The Guidelines made significant changes to the use of surveillance techniques to detect stenosis and found insufficient evidence to make a recommendation for routine arteriovenous fistula surveillance by measuring access blood flow, pressure monitoring, or imaging for stenosis that was in addition to routine clinical monitoring. Routine surveillance is not recommended in arteriovenous grafts. Similarly, pre-emptive angioplasty of arteriovenous fistulas or arteriovenous grafts with stenosis, not associated with clinical indicators, is not recommended. The Guidelines represent a rigorous review of the evidence; however, the available evidence to guide vascular access practice remains limited. There is a significant need and opportunity for new and ongoing high-quality research to inform best practice.

Association of Baclofen With Encephalopathy in Patients With Chronic Kidney Disease

IMPORTANCE

At least 30 case reports have linked the muscle relaxant baclofen to encephalopathy in patients with chronic kidney disease (CKD).

OBJECTIVE

To compare the 30-day risk of encephalopathy in patients with CKD and newly prescribed baclofen at greater than or equal to 20 mg per day vs less than 20 mg per day. The secondary objective was to compare the risk of encephalopathy in baclofen users vs nonusers.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective population-based cohort study in Ontario, Canada (2007-2018) using linked health care data. Participants comprised 15 942 older adults (aged 66 years or older) with CKD (defined as an estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 but not receiving dialysis). The primary cohort was restricted to patients who were newly prescribed baclofen; participants in the secondary cohort were new users and nonusers.

EXPOSURES

Prescription for oral baclofen greater than or equal to 20 mg per day vs less than 20 mg per day.

MAIN OUTCOMES AND MEASURES

Hospital admission with encephalopathy, defined as a main diagnosis of delirium, disorientation, transient alteration of awareness, transient cerebral ischemic attack, or unspecified dementia within 30 days of starting baclofen. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on indicators of baseline health. Weighted risk ratios (RRs) were obtained using modified Poisson regression and weighted risk differences (RDs) using binomial regression. Prespecified subgroup analyses were conducted by eGFR category.

RESULTS

The primary cohort comprised 15 942 patients with CKD (9699 [61%] women; median age, 77 years [interquartile range, 71-82]; 9707 [61%] patients started baclofen at ≥20 mg/d and 6235 [39%] at <20 mg/d). The primary outcome, hospitalization with encephalopathy, occurred in 108/9707 (1.11%) patients who started baclofen at greater than or equal to 20 mg per day and in 26/6235 (0.42%) who started baclofen at less than 20 mg per day; weighted RR, 3.54 (95% CI, 2.24 to 5.59); weighted RD, 0.80% (95% CI, 0.55% to 1.04%). In subgroup analysis, the absolute risk increased progressively at lower eGFR (weighted RD eGFR 45-59, 0.42% [95% CI, 0.19%-0.64%]; eGFR 30-44, 1.23% [95% CI, 0.62%-1.84%]; eGFR <30, 2.90% [95% CI, 1.30%-4.49%]; P for interaction, <.001]). In the secondary comparison with 284 263 nonusers, both groups of baclofen users had a higher risk of encephalopathy (<20 mg/d weighted RR, 5.90 [95% CI, 3.59 to 9.70] and ≥20 mg/d weighted RR, 19.8 [95% CI, 14.0 to 28.0]).

CONCLUSIONS AND RELEVANCE

Among older patients with CKD who were newly prescribed baclofen, the 30-day incidence of encephalopathy was increased among those prescribed higher doses compared with lower doses. If verified, these risks should be balanced against the benefits of baclofen use.

Hydration Status and Kidney Health of Factory Workers Exposed to Heat Stress: A Pilot Feasibility Study

Dehydration associated with heat stress increases the risk of workplace injury or illness, decreases productivity, and may contribute to the chronic kidney disease epidemic identified in outdoor workers from hot climates. There is limited research on the effects of chronic occupational heat stress among indoor workers. We aimed to test the feasibility of measuring markers of hydration and kidney function in foundry factory workers in Southern Brazil, exposed and not exposed to heat stress. Factory workers exposed to heat stress (wet bulb globe temperature ≥28.9) and not exposed to heat were identified by management and invited to participate. Clinical and biochemical markers of hydration and kidney function were evaluated before and after a single 8.5 h work shift (lunch time not included). Feasibility outcomes included rates of enrolment, % completion of study protocols, and time to complete data collection. This study was deemed feasible with 80% enrolment and 90% completion of the protocol. Among the preselected workers, the enrolment rate was 91%. All subjects completed the physiological measures and blood collection and 95% completed the urine studies. Mean time to complete data collection pre-shift was 19.1 ± 4.2 min and post-shift: 14.3 ± 4.0 min. Workers exposed to heat stress had a greater decline in estimated glomerular filtration rate compared to controls over the work shift (–13 ± 11 vs. –5 ± 7 mL/min; p < 0.01). We demonstrated the feasibility and challenges of conducting future hydration and kidney function research among indoor factory workers. Further study is needed to determine if exposure to indoor heat contributes to a decline in kidney function.

Con: Vascular access surveillance in mature fistulas: is it worthwhile?

The risks and benefits of hemodialysis arteriovenous (AV) access surveillance have been debated since the introduction of AV access surveillance techniques. The debate is fuelled by the lack of robust, high-quality evidence with consistent and comparable patient-important outcomes. Additionally, there is a lack of clarity regarding the diagnostic cut points for AV access stenosis using the various surveillance techniques, questions about the appropriateness of the ‘knee-jerk’ response to intervention on a stenosis >50% regardless of the presence of clinical indicators and whether the intervention results in desired patient-important outcomes. The physiology of the AV access is complex considering the different hemodynamics within an AV fistula, which vary by time of dialysis, location, size of vessels and location of the stenosis. The current evidence suggests that the use of AV access surveillance in an AV fistula does detect more stenosis compared with clinical monitoring alone and leads to an increased number of procedures. It remains uncertain if that leads to improved patient-important outcomes such as prolonged AV fistula patency. Vascular access is an essential component of hemodialysis and further study is needed to clarify this long-standing debate. There needs to be better distinction between the strategies of vascular access surveillance, clinical monitoring with clinical indictors and preemptive intervention and their respective impacts on patient-important outcomes. Randomized controlled studies must be conducted with defined indications for intervention, reproducible methods of intervention and clinically important AV fistula and patient outcomes. The current guidelines need to be challenged and revised to permit these necessary studies to be done.

Oral curcumin in elective abdominal aortic aneurysm repair: a multicentre randomized controlled trial

BACKGROUND

Curcumin, a popular herbal supplement from the plant turmeric, has prevented ischemic reperfusion and toxin-induced injury in many animal studies and a single-centre randomized human trial. We sought to test whether perioperative oral curcumin (compared with placebo) affects the inflammatory response and risk of postrepair complications after elective abdominal aortic aneurysm repair in humans.

METHODS

We conducted a parallel-group, randomized, placebo-controlled trial of patients from 10 hospitals in Canada who were scheduled to undergo elective repair of an unruptured abdominal aortic aneurysm (November 2011 to November 2014). Patients in the treatment group received perioperative oral curcumin (2000-mg doses 8 times over 4 d). Patients, health care providers and local research staff were unaware of the treatment assignment. The primary outcomes were median concentrations of 4 bio markers indicating injury and inflammation (postoperative urine interleukin-18 and perioperative rise in serum creatinine, plasma N-terminal pro-B-type natriuretic peptide and plasma high-sensitivity C-reactive protein).

RESULTS

Baseline characteristics were similar in the 2 groups (606 patients overall; median age 76 yr). More than 85% of patients in each group took more than 80% of their scheduled capsules. Neither curcumin nor placebo significantly affected any of the 4 biomarkers (p > 0.05 for all comparisons). Regarding the secondary outcomes, there was a higher risk of acute kidney injury with curcumin than with placebo (17% v. 10%, p = 0.01), but no between-group difference in the median length of hospital stay (5 v. 5 days, p > 0.9) or the risk of clinical events (9% v. 9%, p = 0.9).

INTERPRETATION

Curcumin had no beneficial effects when used in elective abdominal aortic aneurysm repair. These findings emphasize the importance of testing turmeric and curcumin before espousing their health benefits, as is currently done in the popular media.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT01225094.

Outcomes of the First and Second Hemodialysis Fistula: A Cohort Study

RATIONALE & OBJECTIVE

Fistulas are the preferred form of hemodialysis access; however, many fistulas fail to mature into usable accesses after creation. Data for outcomes after placement of a second fistula are limited.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

People who initiated hemodialysis therapy in any of 5 Canadian dialysis programs (2004-2012) and had at least 1 hemodialysis fistula placed.

PREDICTOR

Second versus initial fistula; receipt of 2 versus 1 fistula; second versus first fistula in recipients of 2 fistulas.

OUTCOMES

Catheter-free fistula use during 1 year following initiation of hemodialysis therapy or following fistula creation, if created after hemodialysis therapy start; proportion of time with catheter-free use; time to catheter free use; time of functional patency.

ANALYTICAL APPROACH

Logistic regression; fractional regression.

RESULTS

Among the 1,091 study participants (mean age, 64±15 [SD] years; 63% men; 59% with diabetes), 901 received 1 and 190 received 2 fistulas. 38% of second fistulas versus 46% of first fistulas were used catheter free at least once. Average percentages of time that second and initial fistulas were used catheter free were 34% and 42%, respectively (OR, 0.72; 95% CI, 0.54-0.94). Compared with people who received 1 fistula, those who received 2 fistulas were less likely to achieve catheter-free use (26% vs 56%) and remain catheter free (23% vs 49% of time; OR, 0.30, 95% CI, 0.24-0.39). Among people who received 2 fistulas, the proportion of time that the second fistula was used catheter free was 11% higher with each 10% greater proportion of time that the first fistula was used catheter free (95% CI, 1%-22%). Model discrimination was modest (C index, 0.69).

LIMITATIONS

Unknown criteria for patient selection for 1 or 2 fistulas; unknown reasons for prolonged catheter use.

CONCLUSIONS

Outcomes of a second fistula may be inferior to outcomes of the initial fistula. First and second fistula outcomes are weakly correlated and difficult to predict based on clinical characteristics.

Hospitalizations in Dialysis Patients in Canada: A National Cohort Study

Background:

Hospitalizations of chronic dialysis patients have not been previously studied at a national level in Canada. Understanding the scope and variables associated with hospitalizations will inform measures for improvement.

Objective:

To describe the risk of all-cause and infection-related hospitalizations in patients on dialysis.

Design:

Retrospective cohort study using health care administrative databases.

Setting:

Provinces and territories across Canada (excluding Manitoba and Quebec).

Patients:

Incident chronic dialysis patients with a dialysis start date between January 1, 2005, and March 31, 2014. Patients with a prior history of kidney transplantation were excluded.

Measurements:

Patient characteristics were recorded at baseline. Dialysis modality was treated as a time-varying covariate. The primary outcomes of interest were all-cause and dialysis-specific infection-related hospitalizations.

Methods:

Crude rates for all-cause hospitalization and infection-related hospitalization were determined per patient year (PPY) at 7 and 30 days, and at 3, 6, and 12 months postdialysis initiation. A stratified, gamma-distributed frailty model was used to assess repeat hospital admissions and to determine the inter-recurrence dependence of hospitalizations within individuals, as well as the hazard ratio (HR) attributed to each covariate of interest.

Results:

A total of 38 369 incident chronic dialysis patients were included: 38 088 adults and 281 pediatric patients (age less than 18 years). There were 112 374 hospitalizations, of which 11.5% were infection-related hospitalizations. The all-cause hospitalization rate was similar for all adult age groups (age 65 years and older: 1.40, 1.35, and 1.18 admissions PPY at 7 days, 30 days, and 6 months, respectively). The all-cause hospitalization rate was higher for pediatric patients (1.67, 2.48, and 2.47 admissions PPY at 7 days, 30 days, and 6 months, respectively; adjusted HR: 2.73, 95% confidence interval [CI]: 2.37-3.15, referent age group: 45-64 years). Within the first 7 days after dialysis initiation, patients on peritoneal dialysis had a higher risk of all-cause hospitalization (HR: 1.27, 95% CI: 1.07-1.50) and infection-related hospitalization (HR: 2.05, 95% CI: 1.19-3.55) compared with patients on hemodialysis. Beyond 7 days, the risk did not differ significantly by dialysis modality. Female sex and Indigenous race were significant risk factors for all-cause hospitalization.

Limitations:

The cohort had too few home hemodialysis patients to examine this subgroup. The outcome of infection-related hospitalization was determined using diagnostic codes. Dialysis patients from Manitoba and Quebec were not included.

Conclusions:

In Canada, the rates of hospitalization were not influenced by dialysis modality beyond the initial 7-day period following dialysis initiation; however, the rate of hospitalization in pediatric patients was higher than in adults at every time frame examined.

Effect of Coaching to Increase Water Intake on Kidney Function Decline in Adults With Chronic Kidney Disease: The CKD WIT Randomized Clinical Trial

IMPORTANCE

In observational studies, increased water intake is associated with better kidney function.

OBJECTIVE

To determine the effect of coaching to increase water intake on kidney function in adults with chronic kidney disease.

DESIGN, SETTING, AND PARTICIPANTS

The CKD WIT (Chronic Kidney Disease Water Intake Trial) randomized clinical trial was conducted in 9 centers in Ontario, Canada, from 2013 until 2017 (last day of follow-up, May 25, 2017). Patients had stage 3 chronic kidney disease (estimated glomerular filtration rate [eGFR] 30-60 mL/min/1.73 m2 and microalbuminuria or macroalbuminuria) and a 24-hour urine volume of less than 3.0 L.

INTERVENTIONS

Patients in the hydration group (n = 316) were coached to drink more water, and those in the control group (n = 315) were coached to maintain usual intake.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in kidney function (eGFR from baseline to 12 months). Secondary outcomes included 1-year change in plasma copeptin concentration, creatinine clearance, 24-hour urine albumin, and patient-reported overall quality of health (0 [worst possible] to 10 [best possible]).

RESULTS

Of 631 randomized patients (mean age, 65.0 years; men, 63.4%; mean eGFR, 43 mL/min/1.73 m2; median urine albumin, 123 mg/d), 12 died (hydration group [n = 5]; control group [n = 7]). Among 590 survivors with 1-year follow-up measurements (95% of 619), the mean change in 24-hour urine volume was 0.6 L per day higher in the hydration group (95% CI, 0.5 to 0.7; P < .001). The mean change in eGFR was -2.2 mL/min/1.73 m2 in the hydration group and -1.9 mL/min/1.73 m2 in the control group (adjusted between-group difference, -0.3 mL/min/1.73 m2 [95% CI, -1.8 to 1.2; P = .74]). The mean between-group differences (hydration vs control) in secondary outcomes were as follows: plasma copeptin, -2.2 pmol/L (95% CI, -3.9 to -0.5; P = .01); creatinine clearance, 3.6 mL/min/1.73 m2 (95% CI, 0.8 to 6.4; P = .01); urine albumin, 7 mg per day (95% CI, -4 to 51; P = .11); and quality of health, 0.2 points (95% CI, -0.3 to 0.3; P = .22).

CONCLUSIONS AND RELEVANCE

Among adults with chronic kidney disease, coaching to increase water intake compared with coaching to maintain the same water intake did not significantly slow the decline in kidney function after 1 year. However, the study may have been underpowered to detect a clinically important difference.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01766687.

Vascular Access Practice Patterns in Canada: A National Survey

Background:

One of the mandates of the Canadian Society of Nephrology’s (CSN) Vascular Access Working Group (VAWG) is to inform the nephrology community of the current status of vascular access (VA) practice within Canada. To better understand VA practice patterns across Canada, the CSN VAWG conducted a national survey.

Objectives:

(1) To inform on VA practice patterns, including fistula creation and maintenance, within Canada. (2) To determine the degree of consensus among Canadian clinicians regarding patient suitability for fistula creation and to assess barriers to and facilitators of fistula creation in Canada.

Design:

Development and implementation of a survey.

Setting:

Community and academic VA programs.

Participants:

Nephrologists, surgeons, and nurses who are involved in VA programs across Canada.

Measurements:

Practice patterns regarding access creation and maintenance, including indications and contraindications to fistula creation, as well as program-wide facilitators of and barriers to VA.

Methods:

A small group of CSN VAWG members determined the scope and created several VA questions which were then reviewed by 5 additional VAWG members (4 nephrologists and 1 VA nurse) to ensure that questions were clear and relevant. The survey was then tested by the remaining members of the VAWG and refinements were made. The final survey version was submitted electronically to relevant clinicians (nephrologists, surgeons, and nurses) involved or interested in VA across Canada. Questions centered around 4 major themes: (1) Practice patterns regarding access creation (preoperative assessment and maturation assessment), (2) Practice patterns regarding access maintenance (surveillance and salvage), (3) Indications and contraindications for arteriovenous (AV) access creation, and (4) Facilitators of and barriers to fistula creation and utilization.

Results:

Eighty-two percent (84 of 102) of invited participants completed the survey; the majority were nurses or VA coordinators (55%) with the remainder consisting of nephrologists (21%) and surgeons (20%). Variation in practice was noted in utility of preoperative Doppler ultrasound, interventions to assist nonmaturing fistulas, and procedures to salvage failing or thrombosed AV-access. Little consensus was seen regarding potential contraindications to AV-access creation (with the exception of limited life expectancy and poor vasculature on preoperative imaging, which had high agreement). Frequent barriers to fistula utilization were primary failure (77% of respondents) and long maturation times (73%). Respondents from centers with low fistula prevalence also cited long surgical wait times as an important barrier to fistula creation, whereas those from centers with high fistula prevalence cited access to multidisciplinary teams and interventional radiology as keys to successful fistula creation and utilization.

Conclusions:

There is significant variation in VA practice across Canada and little consensus among Canadian clinicians regarding contraindications to fistula creation. Further high-quality studies are needed with regard to appropriate fistula placement to help guide clinical practice.

Occupational Heat Stress and Kidney Health: From Farms to Factories

Millions of workers around the world are exposed to high temperatures, intense physical activity, and lax labor practices that do not allow for sufficient rehydration breaks. The extent and consequences of heat exposure in different occupational settings, countries, and cultural contexts is not well studied. We conducted an in-depth review to examine the known effects of occupational heat stress on the kidney. We also examined methods of heat-stress assessment, strategies for prevention and mitigation, and the economic consequences of occupational heat stress. Our descriptive review summarizes emerging evidence that extreme occupational heat stress combined with chronic dehydration may contribute to the development of CKD and ultimately kidney failure. Rising global temperatures, coupled with decreasing access to clean drinking water, may exacerbate the effects of heat exposure in both outdoor and indoor workers who are exposed to chronic heat stress and recurrent dehydration. These changes create an urgent need for health researchers and industry to identify work practices that contribute to heat-stress nephropathy, and to test targeted, robust prevention and mitigation strategies. Preventing occupational heat stress presents a great challenge for a concerted multidisciplinary effort from employers, health authorities, engineers, researchers, and governments.

The Chronic Kidney Disease Water Intake Trial: Protocol of a Randomized Controlled Trial

Background:

In observational studies, drinking more water associates with a slower rate of kidney function decline; whether the same is true in a randomized controlled trial is unknown.

Objective:

To examine the 1-year effect of a higher vs usual water intake on estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease.

Design:

Parallel-group randomized controlled trial.

Setting:

Nine centers in Ontario, Canada. Enrollment and randomization occurred between May 2013 and May 2016; follow-up for the primary outcome will continue until June 2017.

Participants:

Adults (n = 631) with stage 3 chronic kidney disease (eGFR 30-60 mL/min/1.73 m²) and microalbuminuria.

Intervention:

The high water intake group was coached to increase their oral water intake by 1.0 to 1.5 L/day (depending on sex and weight), over and above usual consumed beverages, for a period of 1 year. The control group was coached to maintain their usual water intake during this time.

Measures:

Participants provided 24-hour urine samples at baseline and at 6 and 12 months after randomization; urine samples were analyzed for volume, creatinine, osmolality, and the albumin-to-creatinine ratio. Blood samples were obtained at baseline and at 3- to 6-month intervals after randomization, and analyzed for creatinine, copeptin, osmolality, and electrolytes. Other measures collected included health-related quality of life, blood pressure, body mass index, and diet.

Primary outcome:

The between-group change in eGFR from baseline (prerandomization) to 12 months after randomization.

Secondary outcomes:

Change in plasma copeptin concentration, 24-hour urine albumin-to-creatinine ratio, measured creatinine clearance, estimated 5-year risk of kidney failure (using the 4-variable Kidney Failure Risk Equation), and health-related quality of life.

Planned analysis:

The primary analysis will follow an intention-to-treat approach. The between-group change in eGFR will be compared using linear regression. Supplementary analyses will examine alternative definitions of eGFR change, including annual percentage change, rate of decline, and rapid decline (a P value <0.05 will be interpreted as statistically significant if there is concordance with the primary outcome).

Trial Registration:

This randomized controlled trial has been registered at www.clinicaltrials.gov; government identifier: NCT01766687.

Endovascular Proximal Forearm Arteriovenous Fistula for Hemodialysis Access: Results of the Prospective, Multicenter Novel Endovascular Access Trial (NEAT)

BACKGROUND

Hemodialysis arteriovenous fistulas (AVFs) are suboptimally used primarily due to problems with maturation, early thrombosis, and patient nonacceptance. An endovascular approach to fistula creation without open surgery offers another hemodialysis vascular access option.

STUDY DESIGN

Prospective, single-arm, multicenter study (Novel Endovascular Access Trial [NEAT]).

SETTINGS & PARTICIPANTS

Consecutive adult non-dialysis-dependent and dialysis-dependent patients referred for vascular access creation at 9 centers in Canada, Australia, and New Zealand.

INTERVENTION

Using catheter-based endovascular technology and radiofrequency energy, an anastomosis was created between target vessels, resulting in an endovascular AVF (endoAVF).

OUTCOMES

Safety, efficacy, functional usability, and patency end points.

MEASUREMENTS

Safety as percentage of device-related serious adverse events; efficacy as percentage of endoAVFs physiologically suitable (brachial artery flow ≥ 500mL/min, vein diameter ≥ 4mm) for dialysis within 3 months; functional usability of endoAVFs to provide prescribed dialysis via 2-needle cannulation; primary and cumulative endoAVF patencies per standardized definitions.

RESULTS

80 patients were enrolled (20 roll-in and 60 participants in the full analysis set; the latter are reported). EndoAVFs were created in 98% of participants; 8% had a serious procedure-related adverse event (2% device related). 87% were physiologically suitable for dialysis (eg, mean brachial artery flow, 918mL/min; endoAVF vein diameter, 5.2mm [cephalic vein]). EndoAVF functional usability was 64% in participants who received dialysis. 12-month primary and cumulative patencies were 69% and 84%, respectively.

LIMITATIONS

Due to the unique anatomy and vessels used to create endoAVFs, this was a single-arm study without a surgical comparator.

CONCLUSIONS

An endoAVF can be reliably created using a radiofrequency magnetic catheter-based system, without open surgery and with minimal complications. The endoAVF can be successfully used for hemodialysis and demonstrated high 12-month cumulative patencies. It may be a viable alternative option for achieving AVFs for hemodialysis patients in need of vascular access.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Hemodialysis Infection Prevention Protocols Ontario-Shower Technique (HIPPO-ST): A Pilot Randomized Trial

INTRODUCTION

We developed the Hemodialysis Infection Prevention Protocols Ontario-Shower Technique (HIPPO-ST) to permit hemodialysis (HD) patients with central venous catheters (catheters) to shower without additional infection risk. Our primary objective was to determine the feasibility of conducting a parallel randomized controlled trial (RCT) to evaluate the impact of HIPPO-ST on catheter-related bacteremia (CRB) in adult HD patients.

METHODS

Adult HD patients using catheters were recruited from 11 HD units. Patients were randomized to receive HIPPO-ST or standard care and were followed up for 6 months. Only CRB-outcome assessors were blinded. For the study to be considered feasible, 4 of 5 feasibility outcomes, each with its own statistical threshold for success, must have been achieved.

RESULTS

A total of 68 patients were randomized (33 HIPPO-ST and 35 control) and were followed up to 6 months. Of 5 measures of feasibility, 4 were achieved: (1) accurate CRB rate documented (threshold: κ level >0.80); (2) 97.8% (279/285) of satellite HD patients with catheters were screened (threshold: >95%); (3) 88% (23/26) in the HIPPO-ST arm were successfully educated by 6 months (threshold: >80%); and (4) 0% (0/29) patients in the control arm were "contaminated," that is, using HIPPO-ST (threshold: <5%). However, only 44.2% (72/163) of eligible patients consented to participate (threshold: >80%). The rate of CRB was similarly low in HIPPO-ST and control groups (0.68 vs. 0.88/1000 catheter days).

DISCUSSION

This HIPPO-ST pilot study demonstrated the feasibility of the larger HIPPO-ST study, especially given the high levels of education success with the HIPPO-ST arm and the low levels of contamination in the control arm.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Hemodialysis Tunneled Catheter-Related Infections

Catheter-related bloodstream infections, exit-site infections, and tunnel infections are common complications related to hemodialysis central venous catheter use. The various definitions of catheter-related infections are reviewed, and various preventive strategies are discussed. Treatment options, for both empiric and definitive infections, including antibiotic locks and systemic antibiotics, are reviewed.

Practical Aspects of Nontunneled and Tunneled Hemodialysis Catheters

Nontunneled hemodialysis catheters (NTHCs) are typically used when vascular access is required for urgent renal replacement therapy. The preferred site for NTHC insertion in acute kidney injury is the right internal jugular vein followed by the femoral vein. When aided by real-time ultrasound, mechanical complications related to NTHC insertion are significantly reduced. The preferred site for tunneled hemodialysis catheters placement is the right internal jugular vein followed by the left internal jugular vein. Ideally, the catheter should be inserted on the opposite side of a maturing or planned fistula/graft. Several dual-lumen, large-diameter catheters are available with multiple catheter tip designs, but no one catheter has shown significant superior performance.

Arteriovenous Access Failure, Stenosis, and Thrombosis

Vascular access–related complications can lead to patient morbidity and reduced patient quality of life. Some of the common arteriovenous access complications include failure to mature, stenosis formation, and thrombosis.

Arteriovenous Vascular Access Selection and Evaluation

When making decisions regarding vascular access creation, the clinician and vascular access team must evaluate each patient individually with consideration of life expectancy, timelines for dialysis start, risks and benefits of access creation, referral wait times, as well as the risk for access complications. The role of the multidisciplinary team in facilitating access choice is reviewed, as well as the clinical evaluation of the patient.

Arteriovenous Access: Infection, Neuropathy, and Other Complications

Complications of vascular access lead to morbidity and may reduce quality of life. In this module, we review both infectious and noninfectious arteriovenous access complications including neuropathy, aneurysm, and high-output access. For the challenging patients who have developed many complications and are now nearing their last vascular access, we highlight some potentially novel approaches.

Design of the fish oil inhibition of stenosis in hemodialysis grafts (FISH) study

Background Arteriovenous grafts (AVG) are the predominant form of permanent vascular access used among hemodialysis (HD) patients in North America but suffer from high intervention and complication rates associated with vascular stenosis. The fish oil inhibition of stenosis in hemodialysis grafts (FISH) study evaluates the efficacy of fish oil in improving HD graft patency.

Methods This study is a multi-center, randomized, double blind placebo-controlled clinical trial of 232 chronic HD patients who require a new graft access. Participants are randomized to fish oil versus placebo post-operatively. The primary endpoint is the proportion of AVG with loss of native patency within 12 months of creation. Secondary endpoints are aimed to determine the effect of fish oil on factors that may promote stenosis and thrombosis. Cumulative patency rates, survival analysis, and analysis of inflammatory markers and adverse events will provide a better understanding of the potential effect of fish oil on a patient's vascular access and cardiovascular system. The FISH study is registered at current controlled trials (www.controlled-trials.com) ISRCTN: 15838383.

Results Details of the study protocol are described including mechanisms of reducing bias through randomization and double blinding, sample size determination, evaluation of patient adherence, access monitoring, and the safety of using fish oil. The main challenges of designing and implementing this study, including using a natural supplement as an intervention in modern medical practice and recruitment of graft recipients in the `fistula first' environment are discussed. Conclusion This is the first large, multicenter, randomized controlled trial of a natural supplement in preventing HD graft stenosis and thrombosis. Clinical Trials 2007; 4: 357—367. http://ctj.sagepub.com

Hydration and Chronic Kidney Disease Progression: A Critical Review of the Evidence

We performed a comprehensive literature review to examine evidence on the effects of hydration on the kidney. By reducing vasopressin secretion, increasing water intake may have a beneficial effect on renal function in patients with all forms of chronic kidney disease (CKD) and in those at risk of CKD. This potential benefit may be greater when the kidney is still able to concentrate urine (high fluid intake is contraindicated in dialysis-dependent patients). Increasing water intake is a well-accepted method for preventing renal calculi, and current evidence suggests that recurrent dehydration and heat stress from extreme occupational conditions is the most probable cause of an ongoing CKD epidemic in Mesoamerica. In polycystic kidney disease (PKD), increased water intake has been shown to slow renal cyst growth in animals via direct vasopressin suppression, and pharmacologic blockade of renal vasopressin-V2 receptors has been shown to slow cyst growth in patients. However, larger clinical trials are needed to determine if supplemental water can safely slow the loss of kidney function in PKD patients.

Effect of increased water intake on plasma copeptin in patients with chronic kidney disease: results from a pilot randomised controlled trial

OBJECTIVES

Increased water intake may have a beneficial effect on the kidney through suppression of plasma vasopressin. We examined the effect of increased water intake on plasma copeptin (a marker of vasopressin) over 6 weeks in patients with chronic kidney disease.

DESIGN

Secondary analysis of a randomised controlled parallel-group pilot trial.

SETTING

Canada, 2012-2013.

PARTICIPANTS

28 patients with stage 3 chronic kidney disease randomised (2:1) to a hydration (n=17) or control group (n=11).

INTERVENTION

The hydration group was coached to increase water intake by up to 1.5 L/day for 6 weeks. The control group was asked to maintain regular water intake.

MEASURES AND OUTCOMES

Participants provided blood and 24 h urine samples at baseline and 6 weeks. Change in plasma copeptin was compared within and between study groups.

RESULTS

Participants were 64% male with a mean age of 62 years and an estimated glomerular filtration rate of 40 mL/min/1.73 m(2). Between baseline and 6 weeks, 24 h urine volume increased by 0.7 L/day in the hydration group, rising from 2.3 to 3.0 L/day (p=0.01), while decreasing by 0.3 L/day among controls, from 2.0 to 1.7 L/day (p=0.07); between-group difference: 0.9 L/day (95% CI 0.37 to 1.46; p=0.002). In the hydration group, median copeptin decreased by 3.6 pmol/L, from 15.0 to 10.8 pmol/L (p=0.005), while remaining stable among controls at 19 pmol/L (p=0.76; p=0.19 for the between-group difference in median change); the between-group difference in mean change was 5.4 pmol/L (95% CI -1.2 to 12.0; p=0.11).

CONCLUSIONS

Adults with stage 3 chronic kidney disease can be successfully randomised to drink approximately 1 L more per day than controls. This increased water intake caused a significant decrease in plasma copeptin concentration. Our larger 12-month trial will examine whether increased water intake can slow renal decline in patients with chronic kidney disease.

TRIAL REGISTRATION NUMBER

NCT01753466.

Preoperative vascular access evaluation for haemodialysis patients

BACKGROUND

Haemodialysis treatment requires reliable vascular access. Optimal access is provided via functional arteriovenous fistula (fistula), which compared with other forms of vascular access, provides superior long-term patency, requires few interventions, has low thrombosis and infection rates and cost. However, it has been estimated that between 20% and 60% of fistulas never mature sufficiently to enable haemodialysis treatment. Mapping blood vessels using imaging technologies before surgery may identify vessels that are most suitable for fistula creation.

OBJECTIVES

We compared the effect of conducting routine radiological imaging evaluation for vascular access creation preoperatively with standard care without routine preoperative vessel imaging on fistula creation and use.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 14 April 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled adult participants (aged ≥ 18 years) with chronic or end-stage kidney disease (ESKD) who needed fistulas (both before dialysis and after dialysis initiation) that compared fistula maturation rates relating to use of imaging technologies to map blood vessels before fistula surgery with standard care (no imaging).

DATA COLLECTION AND ANALYSIS

Two authors assessed study quality and extracted data. Dichotomous outcomes, including fistula creation, maturation and need for catheters at dialysis initiation, were expressed as risk ratios (RR) with 95% confidence intervals (CI). Continuous outcomes, such as numbers of interventions required to maintain patency, were expressed as mean differences (MD). We used the random-effects model to measure mean effects.

MAIN RESULTS

Four studies enrolling 450 participants met our inclusion criteria. Overall risk of bias was judged to be low in one study, unclear in two, and high in one.There was no significant differences in the number of fistulas that were successfully created (4 studies, 433 patients: RR 1.06, 95% CI 0.95 to 1.28; I² = 76%); the number of fistulas that matured at six months (3 studies, 356 participants: RR 1.11, 95% CI 0.98 to 1.25; I² = 0%); number of fistulas that were used successfully for dialysis (2 studies, 286 participants: RR 1.12, 95% CI 0.99 to 1.28; I² = 0%); the number of patients initiating dialysis with a catheter (1 study, 214 patients: RR 0.66, 95% CI 0.42 to 1.04); and in the rate of interventions required to maintain patency (1 study, 70 patients: MD 14.70 interventions/1000 patient-days, 95% CI -7.51 to 36.91) between the use of preoperative imaging technologies compared with standard care (no imaging).

AUTHORS' CONCLUSIONS

Based on four small studies, preoperative vessel imaging did not improve fistula outcomes compared with standard care. Adequately powered prospective studies are required to fully answer this question.

Increasing Water Intake in Chronic Kidney Disease: Why? Safe? Possible?

Increased water intake may slow the progression of chronic kidney disease by lowering vasopressin levels. Prior to initiating a large randomized controlled trial on the effect of increased water intake on renal decline, we conducted a six-week pilot study to examine the safety and feasibility of asking adults with chronic kidney disease to increase their water intake. We randomly assigned 29 patients to either a hydration or a control group. The hydration group was asked to increase water intake by 1 to 1.5 l/day relative to their weight, gender, and 24 h urine osmolality, in addition to usual consumed beverages; the control group was asked to continue with usual fluid intake. After six weeks, the change in urine volume was significantly different between groups (0.9 l/day; p = 0.002) with no change in serum sodium and no serious adverse effects. Similarly, preliminary results of our large clinical trial of the same intervention (489 patients enrolled to date) demonstrated a significant separation between groups on 24 h urine volume (at 12 months the mean difference between groups was 1.2 l/day; p < 0.001) with no serious adverse effects. Serum sodium has remained stable in both groups over follow-up. To our knowledge, this trial is currently the largest of its kind to date; the significant separation between groups with respect to urine volume indicates that we will have scientifically reliable data on the effect of increased fluid intake on renal decline. The analysis of primary and secondary outcomes will be conducted at the conclusion of follow-up in July 2016.

Inhibiting the progression of arterial calcification with vitamin K in HemoDialysis patients (iPACK-HD) trial: rationale and study design for a randomized trial of vitamin K in patients with end stage kidney disease

Background

Cardiovascular disease, which is due in part to progressive vascular calcification, is the leading cause of death among patients with end stage kidney disease (ESKD) on dialysis. A role for vitamin K in the prevention of vascular calcification is plausible based on the presence of vitamin K dependent proteins in vascular tissue, including matrix gla protein (MGP). Evidence from animal models and observational studies support a role for vitamin K in the prevention of vascular calcification. A large-scale study is needed to investigate the effect of vitamin K supplementation on the progression of vascular calcification in patients with ESKD, a group at risk for sub-clinical vitamin K deficiency.

Methods/Design

We plan a prospective, randomized, double-blind, multicenter controlled trial of incident ESKD patients on hemodialysis in centers within North America. Eligible subjects with a baseline coronary artery calcium score of greater than or equal to 30 Agatston Units, will be randomly assigned to either the treatment group (10 mg of phylloquinone three times per week) or to the control group (placebo administration three times per week). The primary endpoint is the progression of coronary artery calcification defined as a greater than 15% increase in CAC score over baseline after 12 months.

Discussion

Vitamin K supplementation is a simple, safe and cost-effective nutritional strategy that can easily be integrated into patient care. If vitamin K reduces the progression of coronary artery calcification it may lead to decreased morbidity and mortality in men and women with ESKD.

Trial registration

NCT 01528800.