Drug stewardship in chronic kidney disease to achieve effective and safe medication use

People living with chronic kidney disease (CKD) often experience multimorbidity and require polypharmacy. Kidney dysfunction can also alter the pharmacokinetics and pharmacodynamics of medications, which can modify their risks and benefits; the extent of these changes is not well understood for all situations or medications. The principle of drug stewardship is aimed at maximizing medication safety and effectiveness in a population of patients through a variety of processes including medication reconciliation, medication selection, dose adjustment, monitoring for effectiveness and safety, and discontinuation (deprescribing) when no longer necessary. This Review is aimed at serving as a resource for achieving optimal drug stewardship for patients with CKD. We describe special considerations for medication use during pregnancy and lactation, during acute illness and in patients with cancer, as well as guidance for the responsible use of over-the-counter drugs, herbal remedies, supplements and sick-day rules. We also highlight inequities in medication access worldwide and suggest policies to improve access to quality and essential medications for all persons with CKD. Further strategies to promote drug stewardship include patient education and engagement, the use of digital health tools, shared decision-making and collaboration within interdisciplinary teams. Throughout, we position the person with CKD at the centre of all drug stewardship efforts.

Implementation of a One-Day Living Kidney Donor Assessment Clinic to Improve the Efficiency of the Living Kidney Donor Evaluation: Program Report

Purpose of program

A key barrier to becoming a living kidney donor is an inefficient evaluation process, requiring more than 30 tests (eg, laboratory and diagnostic tests), questionnaires, and specialist consultations. Donor candidates make several trips to hospitals and clinics, and often spend months waiting for appointments and test results. The median evaluation time for a donor candidate in Ontario, Canada, is nearly 1 year. Longer wait times are associated with poorer outcomes for the kidney transplant recipient and higher health care costs. A shorter, more efficient donor evaluation process may help more patients with kidney failure receive a transplant, including a pre-emptive kidney transplant (ie, avoiding the need for dialysis). In this report, we describe the development of a quality improvement intervention to improve the efficiency, effectiveness, and patient-centeredness of the donor candidate evaluation process. We developed a One-Day Living Kidney Donor Assessment Clinic, a condensed clinic where interested donor candidates complete all testing and consultations within 1 day.

Sources of information

The One-Day Living Kidney Donor Assessment Clinic was developed after performing a comprehensive review of the literature, receiving feedback from patients who have successfully donated, and meetings with transplant program leadership from St. Joseph's Healthcare Hamilton. A multistakeholder team was formed that included health care staff from nephrology, transplant surgery, radiology, cardiology, social work, nuclear medicine, and patients with the prior lived experience of kidney donation. In the planning stages, the team met regularly to determine the objectives of the clinic, criteria for participation, clinic schedule, patient flow, and clinic metrics.

Methods

Donor candidates entered the One-Day Clinic if they completed initial laboratory testing and agreed to an expedited process. If additional testing was required, it was completed on a different day. Donor candidates were reviewed by the nephrologist, transplant surgeon, and donor coordinator approximately 2 weeks after the clinic for final approval. The team continues to meet regularly to review donor feedback, discuss challenges, and brainstorm solutions.

Key findings

The One-Day Clinic was implemented in March 2019, and has now been running for 4 years, making iterative improvements through continuous patient and provider feedback. To date, we have evaluated more than 150 donor candidates in this clinic. Feedback from donors has been uniformly positive (98% of donors stated they were very satisfied with the clinic), with most noting that the clinic was efficient and minimally impacted work and family obligations. Hospital leadership, including the health care professionals from each participating department, continue to show support and collaborate to create a seamless experience for donor candidates attending the One-Day Clinic.

Limitations

Clinic spots are limited, meaning some interested donor candidates may not be able to enter a One-Day Clinic the same month they come forward.

Implications

This patient-centered quality improvement intervention is designed to improve the efficiency and experience of the living kidney donor evaluation, result in better outcomes for kidney transplant recipients, and potentially increase living donation. Our next step is to conduct a formal evaluation of the clinic, measuring qualitative feedback from health care professionals working in the clinic and donor candidates attending the clinic, and measuring key process and outcome measures in donor candidates who completed the one-day assessment compared with those who underwent the usual care assessment. This program evaluation will provide reliable, regionally relevant evidence that will inform transplant centers across the country as they consider incorporating a similar one-day assessment model.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project

BACKGROUND

The pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care.

METHODS

Observational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019-2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments.

RESULTS

A total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38-1.10) and after 60 days 0.89 (95% CI 0.45-1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups.

CONCLUSION

We observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.

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.

Quality of laboratory biomarker monitoring during treatment with lithium in patients with bipolar disorder

BACKGROUND

Clinical guidelines recommend monitoring of creatinine and lithium throughout treatment with lithium. We here assessed the extent to which this occurs in healthcare in Sweden.

METHODS

This is an observational study of all adults with bipolar disorder starting lithium therapy in Stockholm, Sweden, during 2007-2018. The main outcome was monitoring of blood lithium and creatinine at therapy initiation and/or once annually. The secondary outcome was monitoring of calcium and thyroid-stimulating hormone (TSH). Patients were followed up until therapy cessation, death, out-migration, or to the end of 2018.

RESULTS

We identified 4428 adults with bipolar disorder who started lithium therapy and were followed up for up to 11 years. Their median age was 39 years, and 63% were women. The median duration on lithium therapy was 4.3 (IQR: 1.9-7.45) years, and the majority who discontinued therapy started another mood stabilizer soon after. Overall, 21% started lithium therapy without assessing the serum/plasma concentration of creatinine. The proportion of people who did not have both lithium and creatinine measured increased from 21% in the first year to 33% in the eleventh year. The proportion with annual testing for TSH or calcium was slightly lower. As few as 16% of patients had both lithium and creatinine tested once annually during their complete time on lithium.

CONCLUSIONS

In a Swedish community sample, lithium and creatinine monitoring was inconsistent with guideline recommendations that call for measurement of annual biomarker levels.

Pharmacological strategies to manage hyperkalaemia: out with the old, in with the new? Not so fast…

Since the 1950s, sodium polystyrene sulphonate (SPS) has been the dominant cation exchange agent prescribed for hyperkalaemia. Clinicians have had plenty of time to learn of SPS's advantages and limitations. The demands of drug regulatory agencies regarding the incorporation of medications into the market were not so stringent then as they are today, and the efficacy and safety of SPS have been questioned. In recent years, two novel cation exchangers, patiromer and sodium zirconium cyclosilicate, have received (or are in the process of receiving) regulatory approval in multiple jurisdictions globally, after scrutiny of carefully conducted trials regarding their short-term and mid-term efficacy. In this debate, we defend the view that all three agents are likely to have similar efficacy. Harms are much better understood for SPS than for newer agents, but currently there are no data to suggest that novel agents are safer than SPS. Drug choices need to consider costs, access and numbers-needed-to-treat to prevent clinically important events; for potassium exchangers, we need trials directly examining clinically important events.

Absolute and Relative Risks of Kidney Outcomes Associated With Lithium vs Valproate Use in Sweden

Importance

Among patients with bipolar disorder, discordant findings have been published on the nephrotoxic effects of lithium therapy.

Objective

To quantify absolute and relative risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) in people who initiated lithium compared with valproate therapy and to investigate the association between cumulative use and elevated lithium levels and kidney outcomes.

Design, Setting, and Participants

This cohort study had a new-user active-comparator design and used inverse probability of treatment weights to minimize confounding. Included patients initiated therapy with lithium or valproate from January 1, 2007, to December 31, 2018, and had a median follow-up of 4.5 years (IQR, 1.9-8.0 years). Data analysis began in September 2021, using routine health care data from the period 2006 to 2019 from the Stockholm Creatinine Measurements project, a recurrent health care use cohort of all adult residents in Stockholm, Sweden.

Exposures

New use of lithium vs new use of valproate and high (>1.0 mmol/L) vs low serum lithium levels.

Main Outcomes and Measures

Progression of CKD (composite of >30% decrease relative to baseline estimated glomerular filtration rate [eGFR] and kidney failure), AKI (by diagnosis or transient creatinine elevations), new albuminuria, and annual eGFR decrease. Outcomes by attained lithium levels were also compared in lithium users.

Results

The study included 10 946 people (median [IQR] age, 45 [32-59] years; 6227 female [56.9%]), of whom 5308 initiated lithium therapy and 5638 valproate therapy. During follow-up, 421 CKD progression events and 770 AKI events were identified. Compared with patients who received valproate, those who received lithium did not have increased risk of CKD (hazard ratio [HR], 1.11 [95% CI, 0.86-1.45]) or AKI (HR, 0.88 [95% CI, 0.70-1.10]). Absolute 10-year CKD risks were low and similar: 8.4% in the lithium group and 8.2% in the valproate group. No difference in the risk of developing albuminuria or the annual rate of eGFR decrease was found between groups. Among more than 35 000 routine lithium tests, only 3% of results were in the toxic range (>1.0 mmol/L). Lithium values greater than 1.0 mmol/L, compared with lithium values of 1.0 mmol/L or less, were associated with increased risk of CKD progression (HR, 2.86; 95% CI, 0.97-8.45) and AKI (HR, 3.51; 95% CI, 1.41-8.76).

Conclusions and Relevance

In this cohort study, compared with new use of valproate, new use of lithium was meaningfully associated with adverse kidney outcomes, with low absolute risks that did not differ between therapies. However, elevated serum lithium levels were associated with future kidney risks, particularly AKI, emphasizing the need for close monitoring and lithium dose adjustment.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants

RATIONALE & OBJECTIVE

Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018.

EXPOSURE

Initiation of DOAC or VKA treatment.

OUTCOME

Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism.

ANALYTICAL APPROACH

Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects.

RESULTS

We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m². The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation.

LIMITATIONS

Missing information on time in therapeutic range and treatment dosages.

CONCLUSIONS

Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

Defining measures of kidney function in observational studies using routine health care data: methodological and reporting considerations

The availability of electronic health records and access to a large number of routine measurements of serum creatinine and urinary albumin enhance the possibilities for epidemiologic research in kidney disease. However, the frequency of health care use and laboratory testing is determined by health status and indication, imposing certain challenges when identifying patients with kidney injury or disease, when using markers of kidney function as covariates, or when evaluating kidney outcomes. Depending on the specific research question, this may influence the interpretation, generalizability, and/or validity of study results. This review illustrates the heterogeneity of working definitions of kidney disease in the scientific literature and discusses advantages and limitations of the most commonly used approaches using 3 examples. We summarize ways to identify and overcome possible biases and conclude by proposing a framework for reporting definitions of exposures and outcomes in studies of kidney disease using routinely collected health care data.

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

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

Sex Differences in the Recognition, Monitoring, and Management of CKD in Health Care: An Observational Cohort Study

INTRODUCTION

Reported sex differences in the etiology, population prevalence, progression rates, and health outcomes of people with CKD may be explained by differences in health care.

METHODS

We evaluated sex as the variable of interest in a health care-based study of adults (n=227,847) with at least one outpatient eGFR<60 ml/min per 1.73 m2 measurement denoting probable CKD in Stockholm from 2009 to 2017. We calculated the odds ratios for diagnosis of CKD and provision of RASi and statins at inclusion, and hazard ratios for CKD diagnosis, visiting a nephrologist, or monitoring creatinine and albuminuria during follow-up.

RESULTS

We identified 227,847 subjects, of whom 126,289 were women (55%). At inclusion, women had lower odds of having received a diagnostic code for CKD and were less likely to have received RASi and statins, despite having guideline-recommended indications. In time-to-event analyses, women were less likely to have received a CKD diagnosis (HR, 0.43; 95% CI, 0.42 to 0.45) and visited a nephrologist (HR, 0.46; 95% CI, 0.43 to 0.48) regardless of disease severity, presence of albuminuria, or criteria for referral. Women were also less likely to undergo monitoring of creatinine or albuminuria, including those with diabetes or hypertension. These differences remained after adjustment for comorbidities, albuminuria, and highest educational achievement, and among subjects with confirmed CKD at retesting. Although in absolute terms all nephrology-care indicators gradually improved over time, the observed sex gap persisted.

CONCLUSIONS

There were profound sex differences in the detection, recognition, monitoring, referrals, and management of CKD. The disparity was also observed in people at high risk and among those who had guideline-recommended indications.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2022_10_11_JASN2022030373.mp3.

Pyoderma Gangrenosum After Insertion of a Hemodialysis Catheter: Koebner Phenomenon, Systemic Inflammatory Response Syndrome, and a Delay in Diagnosis

Rationale:

Pyoderma gangrenosum is a rare neutrophilic dermatosis. Misdiagnosis of pyoderma gangrenosum as an infection is not uncommon. Pyoderma gangrenosum can be associated with Koebner phenomenon and rarely results in systemic inflammatory response syndrome and shock.

Presenting concerns of the patient:

A 61-year-old woman had recently started maintenance hemodialysis, using a tunneled catheter. She was admitted with fever and signs of inflammation at the catheter exit site and along the tunnel.

Diagnoses:

The initial diagnosis was catheter-related tunnel infection. The exit site broke down into a 5 cm × 5 cm lesion typical of pyoderma, and a new similar lesion developed at a subcutaneous injection site in her abdomen. Clinical diagnosis of pyoderma gangrenosum was made. She remained febrile despite broad antibiotic coverage and catheter removal and developed systemic inflammatory response syndrome (SIRS) that necessitated transfer to intensive care unit.

Interventions:

She responded well to fluids and intravenous steroids. Viral and bacterial cultures were negative throughout; echocardiography and computed tomography were unrevealing. Insertion of a new hemodialysis catheter was deferred as long as clinically possible, was undertaken while the patient was taking steroids, and was uncomplicated.

Outcomes:

She remained hemodynamically stable and was discharged after rehabilitation. Her wounds slowly granulated and healed. Steroids were tapered.

Teaching points:

To our knowledge, this is the first case report of a patient with pyoderma gangrenosum developing at the site of tunneled hemodialysis catheter. Our patient developed SIRS with no evidence of infection. We summarize 11 previous case reports of pyoderma leading to SIRS and responsive to steroids.

Lipid-lowering treatment intensity, persistence, adherence and goal attainment in patients with coronary heart disease

BACKGROUND

To examine patterns of lipid-lowering therapy (LLT) use, and persistence and adherence among patients with coronary heart disease and their associations with lipoprotein cholesterol (LDL-C) goal attainment.

METHODS

Observational study among 26,768 patients who had suffered a myocardial infarction or had been revascularized in Stockholm during 2012 to 2018, and followed up through 2019. Outcomes included initiation of LLT, discontinuation, re-initiation, adherence to treatment and LDL-C goal attainment according to the European dyslipidaemia guidelines from 2011 and 2016 (mainly LDL-C <1.8 mmol/L).

RESULTS

82% of patients commenced or continued LLT within 90 days after discharge. Of those, 71% were dispensed an LLT prescription within 30 days (62% of them for high-intensity LLT). High-intensity LLT prescribing increased over time, from 12% in 2012 to 78% in 2018. During a median follow-up of 3 (IQR 2-5) years 73% continued to fill prescriptions for a statin, 26.3% temporarily or permanently discontinued, and 0.5% changed to non-statin LLT. Only 1.3% discontinued statin treatment permanently. Throughout observation, about 80% of patients showed good statin adherence (proportion of days covered ≥80%). LDL-C target attainment was 52% the first year and <50% during subsequent years. LDL-C goal attainment was highest among patients receiving high-intensity statin treatment and showing good treatment adherence.

CONCLUSION

In secondary prevention for patients with established coronary heart disease, the proportion of LDL-C target attainment was low throughout the time period of the study, despite increasing use of high-intensity LLT and good treatment persistence and adherence.

Intensity of and Adherence to Lipid-Lowering Therapy as Predictors of Major Adverse Cardiovascular Outcomes in Patients With Coronary Heart Disease

Background The effectiveness of lipid-lowering therapy (LLT) is affected by both intensity and adherence. This study evaluated the associations of LLT intensity, adherence, and the combination of these 2 aspects of LLT management with the risk of major adverse cardiovascular events (MACE) in people with coronary heart disease. Methods and Results This is an observational study of all adults who suffered a myocardial infarction or had coronary revascularization during 2012 to 2018 and initiated LLT in Stockholm, Sweden. Study exposures were LLT adherence (proportion of days covered), LLT intensity (expected reduction of low-density lipoprotein cholesterol), and the combined measure of adherence and intensity. At each LLT fill, adherence and intensity during the previous 12 months were calculated. The primary outcomes were MACE (nonfatal myocardial infarction or stroke and death); secondary outcomes were low-density lipoprotein cholesterol goal attainment and individual components of MACE. We studied 20 490 patients aged 68±11 years, 75% men, mean follow-up 2.6±1.1 years. Every 10% increase in 1-year adherence, intensity, or adherence-adjusted intensity was associated with a lower risk of MACE (hazard ratio [HR], 0.94 [95% CI, 0.93-0.96]; HR, 0.92 [95% CI, 0.88-0.96]; and HR, 0.91 [95% CI, 0.89-0.94], respectively) and higher odds of attaining low-density lipoprotein cholesterol goals (odds ratio [OR],1.12 [95% CI, 1.10-1.15]; OR, 1.42 [95% CI, 1.34-1.51], and OR, 1.16 [95% CI, 1.19-1.24], respectively). Among patients with good adherence (≥80%), the risk of MACE was similar with low-moderate and high-intensity LLT despite differences in the low-density lipoprotein cholesterol goal attainment with the treatment intensities. Discontinuation ≥1 year increased the risk markedly (HR,1.66 [95% CI, 1.23-2.22]). Conclusions In routine care, good adherence to LLT was associated with the greatest benefit for patients with coronary heart disease. Strategies that improve adherence and use of intensive therapies could substantially reduce cardiovascular risk.

Removing race from the CKD-EPI equation and its impact on prognosis in a predominantly White European population

BACKGROUND

While American nephrology societies recommend using the 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate (eGFR) equation without a Black race coefficient, it is unknown how this would impact disease distribution, prognosis and kidney failure risk prediction in predominantly White non-US populations.

METHODS

We studied 1.6 million Stockholm adults with serum/plasma creatinine measurements between 2007 and 2019. We calculated changes in eGFR and reclassification across KDIGO GFR categories when changing from the 2009 to 2021 CKD-EPI equation; estimated associations between eGFR and the clinical outcomes kidney failure with replacement therapy (KFRT), (cardiovascular) mortality and major adverse cardiovascular events using Cox regression; and investigated prognostic accuracy (discrimination and calibration) of both equations within the Kidney Failure Risk Equation.

RESULTS

Compared with the 2009 equation, the 2021 equation yielded a higher eGFR by a median [interquartile range (IQR)] of 3.9 (2.9-4.8) mL/min/1.73 m2, which was larger at older age and for men. Consequently, 9.9% of the total population and 36.2% of the population with CKD G3a-G5 was reclassified to a higher eGFR category. Reclassified individuals exhibited a lower risk of KFRT, but higher risks of all-cause/cardiovascular death and major adverse cardiovascular events, compared with non-reclassified participants of similar eGFR. eGFR by both equations strongly predicted study outcomes, with equal discrimination and calibration for the Kidney Failure Risk Equation.

CONCLUSIONS

Implementing the 2021 CKD-EPI equation in predominantly White European populations would raise eGFR by a modest amount (larger at older age and in men) and shift a major proportion of CKD patients to a higher eGFR category. eGFR by both equations strongly predicted outcomes.

FC078: Impact of Removing Race from the CKD-EPI Equation: Analysis of 1.6 Million Swedish Adults

BACKGROUND AND AIMS

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) recently developed a novel creatinine-based eGFR equation without a race coefficient. While American nephrology societies recommend using this novel equation, its implications are unknown.

METHOD

We included 1.6 million adult individuals with routine outpatient serum creatinine testing during 2007–2018 in Stockholm, Sweden. First, we calculated reclassification across KDIGO eGFR categories when changing from the 2009 to 2021 CKD-EPI equation. Second, for both equations, the association between eGFR and (1) kidney failure with replacement therapy (KFRT), (2) all-cause mortality, (3) cardiovascular mortality and (4) major adverse cardiovascular events was estimated with Cox regression. Third, prognostic accuracy of both eGFR equations within the Kidney Failure Risk Equation was assessed with discrimination and calibration.

RESULTS

Compared with the 2009 equation, the 2021 equation yielded a higher eGFR by a median (IQR) of 3.9 (2.9–4.8) mL/min/1.73 m2, decreasing prevalence of CKD G3–G5 from 5.1 to 3.8%. The 2021 equation reclassified 9.9% of the total population and 36.2% of the CKD G3–G5 population to a less severe eGFR category. Individuals who were reclassified to less severe eGFR categories were older and therefore exhibited higher crude risks of all-cause/cardiovascular death and major adverse cardiovascular events, and lower risk of kidney replacement therapy compared with nonreclassified participants of similar eGFR. eGFR by both equations strongly predicted study outcomes, with similar discrimination and calibration for the Kidney Failure Risk Equation.

CONCLUSION

Implementing the 2021 CKD-EPI equation in predominantly white European populations raises eGFR by a modest amount (larger at older age and men) and shifts a major proportion of CKD patients to a higher eGFR category, with eGFR by both equations strongly predicting outcomes.

FC 129: Stopping versus Continuing Renin–Angiotensin System Inhibitors After Acute Kidney Injury and Adverse Clinical Outcomes: An Observational Study From Routine Care Data

BACKGROUND AND AIMS

The risk–benefit ratio of continuing with renin–angiotensin system inhibitors (RASi) after an episode of acute kidney injury (AKI) is unclear. While stopping RASi may prevent recurrent AKI or hyperkalaemia, it may deprive patients of the cardiovascular benefits of using RASi.

METHOD

We analysed outcomes of long-term RASi users experiencing AKI (stage 2 or 3, or clinically coded) during hospitalization in Stockholm, Sweden, during 2007–2018. We compared stopping RASi within 3 months after discharge with continuing. The primary study outcome was the composite of all-cause mortality, myocardial infarction and stroke. Recurrent AKI was our secondary outcome, and we considered hyperkalaemia as a positive control outcome. Propensity score overlap weighted Cox models were used to estimate hazard ratios, balancing 75 confounders. Weighted absolute risk differences (ARD) were also determined.

RESULTS

We included 10 165 individuals, of whom 4429 stopped and 5736 continued RASi, with a median follow-up of 2.3 years. Median age was 78 years, 45% were women, and median kidney function before the index episode of AKI was 55 mL/min/1.73 m2. After weighting, those who stopped had an increased risk [HR, 95% confidence interval (95% CI)] of the composite of death, myocardial infarction and stroke (1.13, 1.07–1.19; ARD 3.7, 95% CI 2.6–4.8) compared with those who continued, a similar risk of recurrent AKI (0.94, 0.84–1.05), and a decreased risk of hyperkalaemia (0.79, 0.71–0.88).

CONCLUSION

Stopping RASi use among survivors of moderate-to-severe AKI was associated with a similar risk of recurrent AKI, but higher risk of the composite of death, myocardial infarction and stroke.

FC006: Sex Differences in the Recognition, Monitoring and Management of Chronic Kidney Disease in Health Care

BACKGROUND AND AIMS

Sex-specific differences exist in the population prevalence of chronic kidney disease (CKD), progression rates and health outcomes. Recognition, diagnosis and monitoring are central processes in the management of patients with CKD, but it is unknown whether these processes differ between men and women.

METHOD

This is an observational cohort study of all adult individuals (n = 227 847) with at least one eGFR (from serum creatinine) &lt;60 mL/min/1.73 m2 during outpatient routine care in Stockholm, Sweden, 2009–2017. Through logistic regression, we evaluated differences by sex in carrying an ICD-10 code for CKD and provision of recommended medications (renin–angiotensin system inhibitors [RASi] and statins) at inclusion. Through Cox regression, we evaluated potential sex differences in receiving a CKD diagnosis, referral to nephrology care and performance of laboratory monitoring (creatinine and albuminuria) in the next 18 months from inclusion. We also explored time-trends, comparing the above-mentioned nephrology care indicators among 70–80 000 unique eligible individuals per calendar year (in total 695 632 observations), thus allowing participants to contribute to different calendar year-cohorts.

RESULTS

We identified more women (55%) than men (45%) with probable CKD (eGFR &lt; 60 mL/min/1.73 m2). Women were generally older than men (median 77 versus 74 years), but eGFR was similar between sexes (51 mL/min/1.73 m2). More men than women had diabetes or myocardial infarction, but there was similar prevalence of hypertension. At inclusion and compared with men, women had lower risk of carrying an ICD-10 code for CKD (odds ratio [OR]: 0.47, 95% CI: 0.45–0.49) and were less likely to receive RASi (OR: 0.55; 0.50–0.61, among patient with albuminuria A3) or statins (OR: 0.64; 0.63–0.66, among patients ≥ 50 years), despite the presence of clear indications. In subsequent time-to-event analyses, women were less likely to receive a CKD diagnosis (hazard ratio [HR]: 0.43; 0.42–0.45) and visit a nephrologist (HR: 0.46; 0.43–0.48) regardless of CKD severity, presence of albuminuria or criteria for referral. Women were also less likely to undergo monitoring of creatinine or albuminuria, even among participants with diabetes (HR: 0.75; 0.74–0.76) or hypertension (HR: 0.76; 0.75–0.78). Multivariable adjustment including comorbidities, eGFR and indication for referral showed some attenuation of the effect, but a sex difference remained. Although in absolute terms there has been a gradual improvement in all nephrology care indicators over time, the observed sex gap persisted throughout.

CONCLUSION

We found profound sex differences in the detection, recognition, monitoring and management (including referrals) of CKD in healthcare, also across high-risk groups and indications.

MO502: Use of Lithium, Valproate and the Risk of Acute or Chronic Kidney Disease: An Observational Study From Routine Care Data

BACKGROUND AND AIMS

Lithium is an established treatment for bipolar disorder and treatment-resistant depression. Despite awareness of potential kidney damage, there is a lack of research evidence to inform on the existence and magnitude of the risk. Observational studies to date show conflicting findings, possibly explained by inadequate control populations, prevalent user bias and a lack of information on kidney function or serum lithium levels.

METHOD

We conducted a cohort study to compare kidney outcomes in adults who started lithium or valproate therapy in Stockholm, Sweden, during 2007–18. Within lithium users, we also compared outcomes by average serum lithium concentrations during the first year of therapy. Kidney outcomes were CKD progression (composite of &gt;30% eGFR decline and kidney failure) and AKI (by diagnosis or KDIGO transient creatinine elevations). Propensity score weighted Cox regression was used to estimate hazard ratios with [95% confidence intervals (95% CI)] and balance 46 identified confounders. Complete collection of repeated dispensations at Swedish pharmacies allowed modelling of the time-dependent risk associated with cumulative lithium exposure. Sensitivity analyses included restricting to patients with a diagnosis of bipolar disorder, apply a 1-year lag, use of alternative weighting methods and evaluation of eGFR monitoring rates to ascertain surveillance bias between groups.

RESULTS

We included 16 645 individuals, of whom 5308 initiated lithium and 5638 valproate therapy. Their median age was 45 years (57% women) and median eGFR was 99 mL/min/1.73 m2. A total of 179 CKD progression events and 234 AKI were identified during a median of follow-up of 4.3 and 4.2 years, respectively. After propensity score weighting, the adjusted hazard ratio for the risk of CKD progression was 1.12 (95% CI 0.86–1.47) and for AKI 0.88 (95% CI 0.7–1.09). There was a weak, non-statistically significant association between cumulative exposure to lithium and the risk of CKD progression that was not observed for cumulative use of valproate. Results were consistent among patients with a bipolar disorder diagnosis and robust to 1-year lag or alternative weighing methods. A total of 3913 lithium users were on therapy for at least one year and underwent routine serum lithium monitoring. Compared with patients with average serum lithium levels &lt;1.0 mEq/L, those with serum lithium ≥1.0 mEq/L (n = 270) were at a higher risk of both CKD progression (HR: 2.18; 1.28–3.71) and AKI (HR: 1.37; 0.81–2.34).

CONCLUSION

In this analysis of patients from routine clinical practice, the risk of kidney outcomes associated with lithium therapy did not differ from that of valproate. Modest risk magnitudes need to be offset with the effectiveness and anti-suicidal benefits of lithium. However, elevated serum lithium levels strongly predicting kidney risk, emphasizing the need for close monitoring and lithium dose-adjustment.

MO514: Cardiorenal Outcomes Associated With Oral Anticoagulant Use in Patients With Atrial Fibrillation

BACKGROUND AND AIMS

Novel oral anticoagulants (NOAC) are currently the first-line choice for stroke prevention in patients with atrial fibrillation (AF), as they have a better risk/benefit profile compared with vitamin K antagonists (VKA). Secondary analyses of trials suggest that NOAC also reduces kidney outcomes, but this has been less explored.

METHOD

Observational study from the SCREAM project comparing clinical outcomes of all persons with AF and eGFR ≥15 mL/min/1.73 m2 that initiated NOAC or VKA in Stockholm, Sweden, during 2011–18. The primary outcomes were acute kidney injury (AKI, by diagnosis or sudden creatinine elevation) and the composite of kidney failure and &gt;30% eGFR decline. Secondary outcomes were major bleeding and the composite of hospital admission with stroke or systemic embolism. Inverse probability of treatment weighting (IPTW) was used to balance 51 baseline confounders. Sensitivity analyses included falsification endpoints (pneumonia and cataract surgery), subgroups and evaluation of per-protocol effects.

RESULTS

A total of 32 699 patients initiated oral anticoagulants (median age, 75 years, 45% women, median eGFR 73 mL/min/1.73 m2), of which 18 323 (56%) used NOAC. Compared with VKA, initiation of NOAC was associated with a 13% lower relative risk of experiencing the composite kidney outcome (HR: 0.87; 95% CI 0.78–0.98) and a 12% relative risk reduction on AKI occurrence (HR: 0.88; 95% CI 0.80–0.97). Compared with VKA, NOAC use was associated with a lower risk of major bleeding (HR 0.77; 95% CI 0.67–0.89), but a similar risk of stroke/systemic embolism (HR: 0.93; 95% CI 0.78–1.11). Results were similar across subgroups, including patients with chronic kidney disease (eGFR &lt;60 mL/min/1.73 m2) and when censoring patients at treatment discontinuation or switch.

CONCLUSION

Compared with VKA, and regardless of baseline kidney function, initiation of NOAC was associated with a lower risk of CKD progression, AKI and major bleeding, but a similar risk of the composite of stroke and systemic embolism.

Association of Clonal Hematopoiesis of Indeterminate Potential with Worse Kidney Function and Anemia in Two Cohorts of Patients with Advanced Chronic Kidney Disease

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP) is an inflammatory premalignant disorder resulting from acquired genetic mutations in hematopoietic stem cells. This condition is common in aging populations and associated with cardiovascular morbidity and overall mortality, but its role in CKD is unknown.

METHODS

We performed targeted sequencing to detect CHIP mutations in two independent cohorts of 87 and 85 adults with an eGFR<60 ml/min per 1.73m2. We also assessed kidney function, hematologic, and mineral bone disease parameters cross-sectionally at baseline, and collected creatinine measurements over the following 5-year period.

RESULTS

At baseline, CHIP was detected in 18 of 87 (21%) and 25 of 85 (29%) cohort participants. Participants with CHIP were at higher risk of kidney failure, as predicted by the Kidney Failure Risk Equation (KFRE), compared with those without CHIP. Individuals with CHIP manifested a 2.2-fold increased risk of a 50% decline in eGFR or ESKD over 5 years of follow-up (hazard ratio 2.2; 95% confidence interval, 1.2 to 3.8) in a Cox proportional hazard model adjusted for age, sex, and baseline eGFR. The addition of CHIP to 2-year and 5-year calibrated KFRE risk models improved ESKD predictions. Those with CHIP also had lower hemoglobin, higher ferritin, and higher red blood cell mean corpuscular volume versus those without CHIP.

CONCLUSIONS

In this exploratory analysis of individuals with preexisting CKD, CHIP was associated with higher baseline KFRE scores, greater progression of CKD, and anemia. Further research is needed to define the nature of the relationship between CHIP and kidney disease progression.

Can Peer Review Be Kinder? Supportive Peer Review: A Re-Commitment to Kindness and a Call to Action

Peer review aims to select articles for publication and to improve articles before publication. We believe that this process can be infused by kindness without losing rigor. In 2014, the founding editorial team of the Canadian Journal of Kidney Health and Disease (CJKHD) made an explicit commitment to treat authors as we would wish to be treated ourselves. This broader group of authors reaffirms this principle, for which we suggest the terminology “supportive review.”

Fitted filtration efficiency and breathability of 2-ply cotton masks: Identification of cotton consumer categories acceptable for home-made cloth mask construction

The objective of this study was to characterize commercially-available cotton fabrics to determine their suitability as materials for construction of cloth masks for personal and public use to reduce infectious disease spread. The study focused on cottons because of their widespread availability, moderate performance and they are recommended for inclusion in home-made masks by international health authorities. Fifty-two cottons were analyzed by electron microscopy to determine fabric characteristics and fabric weights. Sixteen fabrics were selected to test for breathability and to construct 2-ply cotton masks of a standard design to use in quantitative fit testing on a human participant. Cotton mask fitted filtration efficiencies (FFEs) for 0.02-1 μm ambient and aerosolized sodium chloride particles ranged from 40 to 66% compared with the mean medical mask FFE of 55±2%. Pressure differentials across 2-ply materials ranged from 0.57 to > 12 mm H2O/cm2 on samples of equal surface area with 6 of 16 materials exceeding the recommended medical mask limit. Models were calibrated to predict 2-ply cotton mask FFEs and differential pressures for each fabric based on pore characteristics and fabric weight. Models indicated cotton fabrics from 6 of 9 consumer categories can produce cloth masks with adequate breathability and FFEs equivalent to a medical mask: T-shirt, fashion fabric, mass-market quilting cotton, home décor fabric, bed sheets and high-quality quilting cotton. Masks from one cloth mask and the medical mask were re-tested with a mask fitter to distinguish filtration from leakage. The fabric and medical masks had 3.7% and 41.8% leakage, respectively. These results indicate a well fitted 2-ply cotton mask with overhead ties can perform similarly to a disposable 3-ply medical mask on ear loops due primarily to the superior fit of the cloth mask which compensates for its lower material filtration efficiency.

Stopping Versus Continuing Renin-Angiotensin System Inhibitors After Acute Kidney Injury and Adverse Clinical Outcomes; An Observational Study From Routine Care Data

Background

The risk–benefit ratio of continuing with renin–angiotensin system inhibitors (RASi) after an episode of acute kidney injury (AKI) is unclear. While stopping RASi may prevent recurrent AKI or hyperkalaemia, it may deprive patients of the cardiovascular benefits of using RASi.

Methods

We analysed outcomes of long-term RASi users experiencing AKI (stage 2 or 3, or clinically coded) during hospitalization in Stockholm and Sweden during 2007–18. We compared stopping RASi within 3 months after discharge with continuing RASi. The primary study outcome was the composite of all-cause mortality, myocardial infarction (MI) and stroke. Recurrent AKI was our secondary outcome and we considered hyperkalaemia as a positive control outcome. Propensity score overlap weighted Cox models were used to estimate hazard ratios (HRs), balancing 75 confounders. Weighted absolute risk differences (ARDs) were also determined.

Results

We included 10 165 individuals, of whom 4429 stopped and 5736 continued RASi, with a median follow-up of 2.3 years. The median age was 78 years; 45% were women and median kidney function before the index episode of AKI was 55 mL/min/1.73 m². After weighting, those who stopped had an increased risk [HR, 95% confidence interval (CI)] of the composite of death, MI and stroke [1.13, 1.07–1.19; ARD 3.7, 95% CI 2.6–4.8] compared with those who continued, a similar risk of recurrent AKI (0.94, 0.84–1.05) and a decreased risk of hyperkalaemia (0.79, 0.71–0.88).

Discussion

Stopping RASi use among survivors of moderate-to-severe AKI was associated with a similar risk of recurrent AKI, but higher risk of the composite of death, MI and stroke.

Stopping renin-angiotensin system inhibitors after hyperkalemia and risk of adverse outcomes

BACKGROUND

Stopping renin-angiotensin system inhibitors (RASi) after an episode of hyperkalemia is common but may involve therapeutic compromises, in that the cessation of RASi deprives patients of their beneficial cardiovascular effects.

METHODS AND RESULTS

Observational study from the Stockholm Creatinine Measurements (SCREAM) project including patients initiating RASi in routine care and surviving a first-detected episode of hyperkalemia (potassium >5.0 mmol/L). We used target trial emulation techniques based on cloning, censoring and weighting to compare stopping vs. continuing RASi within 6 months after hyperkalemia. Outcomes were 3-year risks of mortality, major adverse cardiovascular events (MACE, composite of cardiovascular death, myocardial infarction and stroke hospitalization) and recurrent hyperkalemia. Of 5669 new users of RASi who developed hyperkalemia (median age 72 years, 44% women), 1425 (25%) stopped RASi therapy within 6 months. Compared with continuing RASi, stopping therapy was associated with a higher 3-year risk of death (absolute risk difference 10.8%; HR 1.49, 95% CI 1.34-1.64) and MACE (risk difference 4.7%; HR 1.29, 1.14-1.45), but a lower risk of recurrent hyperkalemia (risk difference -9.5%; HR 0.76, 0.69-0.84). Results were consistent for events following potassium of >5.0 or >5.5 mmol/L, after censoring when the treatment decision was changed, across prespecified subgroups, and after adjusting for albuminuria.

CONCLUSION

These findings suggest that stopping RASi after hyperkalemia may be associated with a lower risk of recurrence of hyperkalemia, but higher risk of death and cardiovascular events.

Involving Patient Partners in the KRESCENT Peer Review: Intent, Process, Challenges, and Opportunities

Purpose of review:

The Kidney Research Scientist Core Education and National Training (KRESCENT) is a national Canadian training program for kidney scientists, funded by the Kidney Foundation of Canada (KFOC), the Canadian Institutes of Health Research (CIHR), and the Canadian Society of Nephrology (CSN). We describe our first year of incorporating patient partners into a scientific peer-review committee, the 2017 committee to select senior research trainees and early-career kidney researchers for funding and training, in the hope that it will be helpful to others who wish to integrate the perspective of people with lived experience into the peer-review process.

Sources of information:

Other peer-review committees, websites, journal articles, patient partners, Kidney Foundation of Canada Research Council, Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD) Patient Council, participants in the 2017 Kidney Foundation of Canada KRESCENT peer-review panel.

Methods:

We describe our motivation, rationale, guiding principles, plans, feedback, implementation, and response.

Key findings:

We disseminated a “call for patient partners” 8 weeks before the meeting, seeking patients or their care givers to partner with the KRESCENT peer-review panel; we defined these people with lived experience of kidney disease as patient partners. Eight patient partners came forward and all participated as reviewers. Patient partners first participated in a webinar to learn about the function, structure, and processes of a peer-review committee. They practiced reviewing plain language summaries and giving feedback. In a subsequent teleconference, they shared and discussed their reviews. Plain language summaries were scored, overall, on the same 0-5 quality scale used by scientific reviewers. Three patient reviewers participated in some or all of the 6-hour meeting, which was conducted as usual, for this panel, by teleconference (initially audio only; from 2020 onwards by videoconference). In the meeting, the 2 assigned scientific reviewers first gave their scores, followed by the patient reviewers giving their scores, and discussion (mostly scientific, and conducted in usual scientific language). Scientific reviewers then negotiated a consensus score based on their initial scores, the discussion, patient reviewers’ scores and statements, and the scientific officer’s notes. Patient reviewers, scientific reviewers, and the Kidney Foundation of Canada (KFOC) were generally positive about the process. The increased length of the meeting (estimated at 1 hour) was generally thought to be acceptable. Patient reviewers also provided feedback on the methods used to incorporate patients into the research under review. These comments were concrete, insightful, and helpful. The patients did not uniformly recommend that basic scientists involve patients in their work. We did not detect bias against preclinical science, work that did not involve patients, or rarer diseases. Some patients found participation inspiring and enlightening. All participants appreciated the idea of patient partners as community witnesses to a group process committed to fairness and supportiveness. We discussed assigning formal meaningful weight to patient reviewers’ assessments. Most, but not all, patients thought that the scientific reviewers were ultimately the best judges of the allocation of scarce research resources.

Limitations:

Patient participants tended to be Caucasian, middle class, and well educated. Because of the difficulties of travel for some people living with or supporting those living with kidney disease, our findings may not generalize fully to peer-review meetings that are conducted face to face. This is explicitly a supportive panel, committed to reviewing junior scientists with kindness as well as rigor; our findings may not generalize to panels conducted differently. We did not use formal qualitative methodology.

Implications:

Inclusion of patient partners as patient reviewers for the KRESCENT program peer-review panel was feasible, added value for scientific and patient reviewers, and for the funding stakeholders (CIHR, KFOC, and CSN). We were glad that we had taken this step and continue to refine the process with each successive competition.

Timing of dialysis initiation to reduce mortality and cardiovascular events in advanced chronic kidney disease: nationwide cohort study

OBJECTIVE

To identify the optimal estimated glomerular filtration rate (eGFR) at which to initiate dialysis in people with advanced chronic kidney disease.

DESIGN

Nationwide observational cohort study.

SETTING

National Swedish Renal Registry of patients referred to nephrologists.

PARTICIPANTS

Patients had a baseline eGFR between 10 and 20 mL/min/1.73 m2 and were included between 1 January 2007 and 31 December 2016, with follow-up until 1 June 2017.

MAIN OUTCOME MEASURES

The strict design criteria of a clinical trial were mimicked by using the cloning, censoring, and weighting method to eliminate immortal time bias, lead time bias, and survivor bias. A dynamic marginal structural model was used to estimate adjusted hazard ratios and absolute risks for five year all cause mortality and major adverse cardiovascular events (composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) for 15 dialysis initiation strategies with eGFR values between 4 and 19 mL/min/1.73 m2 in increments of 1 mL/min/1.73 m2. An eGFR between 6 and 7 mL/min/1.73 m2 (eGFR6-7) was taken as the reference.

RESULTS

Among 10 290 incident patients with advanced chronic kidney disease (median age 73 years; 3739 (36%) women; median eGFR 16.8 mL/min/1.73 m2), 3822 started dialysis, 4160 died, and 2446 had a major adverse cardiovascular event. A parabolic relation was observed for mortality, with the lowest risk for eGFR15-16. Compared with dialysis initiation at eGFR6-7, initiation at eGFR15-16 was associated with a 5.1% (95% confidence interval 2.5% to 6.9%) lower absolute five year mortality risk and 2.9% (0.2% to 5.5%) lower risk of a major adverse cardiovascular event, corresponding to hazard ratios of 0.89 (95% confidence interval 0.87 to 0.92) and 0.94 (0.91 to 0.98), respectively. This 5.1% absolute risk difference corresponded to a mean postponement of death of 1.6 months over five years of follow-up. However, dialysis would need to be started four years earlier. When emulating the intended strategies of the Initiating Dialysis Early and Late (IDEAL) trial (eGFR10-14 v eGFR5-7) and the achieved eGFRs in IDEAL (eGFR7-10 v eGFR5-7), hazard ratios for all cause mortality were 0.96 (0.94 to 0.99) and 0.97 (0.94 to 1.00), respectively, which are congruent with the findings of the randomised IDEAL trial.

CONCLUSIONS

Very early initiation of dialysis was associated with a modest reduction in mortality and cardiovascular events. For most patients, such a reduction may not outweigh the burden of a substantially longer period spent on dialysis.

GLP-1 receptor agonist versus DPP-4 inhibitor and kidney and cardiovascular outcomes in clinical practice in type-2 diabetes

Whether glucagon-like peptide-1 receptor agonists (GLP1-RA) reduce detrimental kidney outcomes is uncertain. In secondary analyses, trials have shown consistent reductions in macroalbuminuria, but inconclusive results about kidney function decline. To help clarify this, we conducted a cohort study to compare kidney and cardiovascular outcomes in individuals who started GLP1-RA or dipeptidyl peptidase-4 inhibitors (DPP4i) (reduces degradation of endogenous GLP1). The primary outcome was a composite of sustained doubling of creatinine, kidney failure or kidney death. The secondary outcomes were three-point major adverse cardiovascular events (MACE) and its individual components. Propensity score weighted Cox regression was used to balance 53 confounders. A total of 19,766 individuals were included, of whom 5,699 initiated GLP1-RA, and were followed for a median 2.9 years. Mean age was 63 years, 26.2% had atherosclerotic cardiovascular disease and 16.0% had an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73m². The adjusted hazard ratio for GLP1-RA vs. DPP4i was 0.72 (95% confidence interval 0.53-0.98) for the composite kidney outcome and 0.85 (0.73-0.99) for MACE, with absolute five-year risk reductions of 0.8% (0.1%-1.5%) and 1.6% (0.2%-2.9%), respectively. Hazard ratios were 0.79 (0.60-1.05) for cardiovascular death, 0.86 (0.68-1.09) for myocardial infarction and 0.74 (0.59-0.93) for stroke. Results were consistent within subgroups, including age, sex, eGFR and baseline metformin use. Thus, in our analysis of patients from routine clinical practice, the use of GLP1-RA was associated with a lower risk of kidney outcomes compared with DPP4i. Reductions in both kidney outcomes and MACE were similar in magnitude to those reported in large cardiovascular outcome trials.

Navigating Performance Standards for Face Mask Materials: A Custom-Built Apparatus for Measuring Particle Filtration Efficiency

Public health agencies have recommended the community use of face masks to reduce the transmission of airborne diseases like COVID-19. Virus transmission is reduced when masks act as efficient filters, thus evaluating mask particle filtration efficiency (PFE) is essential. However, the high cost and long lead times associated with purchasing turn-key PFE systems or hiring certified laboratories hampers the testing of filter materials. There is a clear need for "custom" PFE test systems; however, the variety of standards that prescribe (medical) face mask PFE testing (e.g., ASTM International, NIOSH) vary widely in their protocols and clarity of guidelines. Herein, the development is described of an "in-house" PFE system and method for testing face masks in the context of current standards for medical masks. Pursuant to the ASTM International standards, the system uses an aerosol of latex spheres (0.1 µm nominal size) with particle concentrations upstream and downstream of the mask material measured using a laser particle analyzer. PFE measurements are obtained for a variety of common fabrics and medical masks. The approach described in this work conforms to the current standards for PFE testing while providing the flexibility to adapt to changing needs and filtration conditions.

Patterns of chronic and transient hyperkalaemia and clinically important outcomes in patients with chronic kidney disease

Background

Whether hyperkalaemia in CKD is chronic or transient, and whether this has different outcome implications, is not known.

Methods

This was an observational study of adults with CKD G3–5 from Stockholm, Sweden 2006–11. We examined individual trajectories of potassium from all measurements obtained through routine outpatient care. For each month of follow-up, we created a rolling assessment of the proportion of time in which potassium was abnormal during the previous 12 months. We defined patterns of hyperkalaemia as transient (≤50% of time during the previous year with potassium >5.0 mmol/L) and chronic (>50% of time with potassium >5.0 mmol/L), and examined whether previous hyperkalaemia pattern offers additional predictive value beyond that provided by the most recent (current) potassium value.

Results

We included 36 511 participants (56% women) with CKD G3–5 and median estimated glomerular filtration rate 46 mL/min/1.73 m². Transient and chronic hyperkalaemia, respectively, were observed in 15% and 4% of patients with CKD G3a, and in 50% and 17% of patients with CKD G5. In fully adjusted models, transient (hazard ratio 1.36, 95% confidence interval 1.29–1.46) or chronic (1.16, 1.04–1.32) hyperkalaemia patterns, but not current hyperkalaemia, were associated with major adverse cardiovascular events (MACE), compared with normokalaemia. Transient hyperkalaemia (1.43, 1.35–1.52) and current potassium values, but not chronic hyperkalaemia, were associated with the risk of death.

Conclusions

Between 4% and 17% of patients with CKD G3–5 develop chronic hyperkalaemia. In general, hyperkalaemia predicted MACE and death; however, the lack of effect of current potassium on MACE when adjusted for the previous pattern, and the stronger effects on death than on MACE, lead us to question whether hyperkalaemia is causal in these relationships.

Re-Envisioning the Canadian Nephrology Trials Network: A Can-SOLVE-CKD Stakeholder Meeting of Patient Partners and Researchers

Purpose

The Canadian Nephrology Trials Network (CNTN) was formed in 2014 to support Canadian researchers in developing, designing, and conducting prospective studies in nephrology. In response to the changing landscape and needs within the Canadian nephrology research community, an interest in further growth and development of the network was identified. In the following report, we describe the process undertaken to re-envision the network through the creation of 3 new committees and how the committees are facilitating change and growth within the CNTN for future sustainability.

Sources of information

To understand areas for improvement and capacity building, the organization charged with overseeing the CNTN, Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD), began by conducting an environmental scan. As well, 2 informal surveys were sent to nephrology professionals (who were members of the CNTN and the Canadian Society of Nephrology) and patient partners (from Can-SOLVE CKD).

Methods

In September 2018, 44 CNTN members and other stakeholders from across Canada (including patient partners and representatives from research funding agencies) convened for a 2-day visioning workshop in Mississauga, Ontario. The agenda for this workshop was largely based on the results from the informal surveys. CNTN leadership participated and chose other workshop participants through informal stakeholder mapping and purposeful recruitment. Patient partners were recruited to participate in the workshop through advertisement within the Can-SOLVE-CKD patient council. The survey results and discussion questions were presented to participants at the workshop who, in turn, discussed in large- and small-group session ways in which the CNTN might be expanded.

Results

Surveys of patient partners indicated that they would like to see greater involvement of patients in the research process. Surveys of researchers indicated that they wanted more support and resources for coordinating prospective trials. The themes which emerged from the workshop discussions were peer review, engagement, and training. These themes were broadened and formally re-named to Scientific Operations, Communications and Engagement, and Capacity Building. A working committee, each co-led by a nephrologist with research experience and a patient partner, was created to advance each of these identified themes. An executive committee was created to provide overall strategic leadership and governance to the network. The Scientific Operations Committee conducts peer reviews; provides letters of endorsement after peer review; and holds semi-annual in-person meetings where researchers can present their proposals and obtain feedback from multiple stakeholders, including patients. The Communications and Engagement Committee publishes a quarterly newsletter, engages the community on Twitter, and reaches out to community sites and new nephrologists to engage them in research. The Capacity Building Committee conducts webinars to encourage patient partners to develop their own research questions and is developing a hub-and-spoke model to improve research collaboration.

Limitations

We did not conduct formal stakeholder mapping. Only attendees of the visioning workshop provided input, and not everyone's comment or opinion was included in the workshop report. Perspectives were limited to the sample of people who attended the workshop or were surveyed and may not reflect perspectives of all stakeholders in nephrology research in Canada. We did not use formal qualitative methodology to summarize the workshops.

Implications

Renewed areas of focus and related committees within the CNTN could lead to an increased capacity for nephrology research, increased engagement and collaboration with researchers, a higher likelihood of funding with rigorous peer review, and more clinical trials and multicenter collaborative prospective research being conducted in Canada.

Stopping mineralocorticoid receptor antagonists after hyperkalaemia: trial emulation in data from routine care

AIMS

Whether to continue or stop mineralocorticoid receptor antagonists (MRA) after an episode of hyperkalaemia is a challenge in clinical practice. While stopping MRA may prevent recurrent hyperkalaemias, it deprives patients of their cardioprotection. We here assessed the association between stopping vs. continuing MRA therapy after hyperkalaemia and the subsequent risks of adverse health events.

METHODS AND RESULTS

Observational study from the Stockholm CREAtinine Measurements (SCREAM) project 2006-2018. We identified patients initiating MRA and surviving a first-detected episode of hyperkalaemia (plasma potassium >5.0 mmol/L). Using target trial emulation methods, we assessed the association between stopping vs. continuing MRA within 6 months after hyperkalaemia and subsequent outcomes. The primary outcome was the composite of hospital admission with heart failure, stroke, myocardial infarction, or death. The secondary outcome was occurrence of another hyperkalaemia event. Among 39 518 patients initiating MRA, we identified 7366 who developed hyperkalaemia. Median age was 76 years, 45% were women and 69% had a history of heart failure. Following hyperkalaemia, 2222 (30%) discontinued treatment. Compared with continuing MRA, stopping therapy was associated with a lower 2-year risk of recurrent hyperkalaemia [hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.72-0.79], but a higher risk of the primary outcome (HR 1.10, 95% CI 1.06-1.14). Similar results were observed in patients with heart failure, after censoring when treatment decision was changed, and across pre-specified subgroups.

CONCLUSIONS

Stopping MRA after an episode of hyperkalaemia was associated with reduced risk for recurrent hyperkalaemia, but higher risk of death or cardiovascular events. Recurrent hyperkalaemia was common in either strategy.

MO493PATTERNS OF HYPERKALEMIA AND ASSOCIATED ADVERSE HEALTH OUTCOMES IN PERSONS WITH CHRONIC KIDNEY DISEASE

Background and Aims

Patients with CKD are often described as having chronic hyperkalemia, but earlier studies have relied on a single potassium measurement. Whether the hyperkalemia in CKD is chronic or transient, and whether temporal patterns have different outcome implications, is unknown.

Method

Observational study from the Stockholm Creatinine Measurements (SCREAM) project of patients with confirmed CKD G3-5. We extracted all data on potassium measured during routine outpatient care and estimated its longitudinal trajectories. At each month, we created a rolling assessment of the proportion of time in which potassium was abnormal during the previous year, defining patterns of normokalemia (100% of time with potassium 3.5-5.0 mmol/L), transient (&lt;50% of time with potassium &gt;5.0 mmol/L) and chronic hyperkalemia (≥50% of time with potassium &gt;5.0 mmol/L). We described the presence of chronic and transient hyperkalemia throughout the spectrum of CKD G3-5 and identified clinical predictors by logistic regression. Through time-dependent Cox models we examined whether previous hyperkalemia patterns offer prognostic gain beyond that of the current potassium value.

Results

We included 36,511 participants (56% women) with confirmed CKD G3-5, median age 81 years, and eGFR 46 ml/min/1.73 m2. During 3-year-median follow-up, patterns of transient and chronic hyperkalemia were observed in 15% and 4% of patients with CKD G3a, increasing to 50% and 17% of patients with CKD G5. Factors associated with chronic hyperkalemia were younger age, male sex, more severe CKD category, presence of diabetes or heart failure, use of renin-angiotensin system inhibitors, and use of potassium binders. Major cardiovascular events (MACE) occurred in 13,104 (36%) patients and 13,570 (37%) died. In time-dependent models, independent of identified confounders and of time-updated potassium values, compared with the normokalemic pattern, patients with transient (HR 1.37, 95% CI 1.29-1.46) or chronic (HR 1.17, 95% CI 1.04-1.32) hyperkalemia patterns were at higher risk of MACE. Transient hyperkalemia pattern (HR 1.43, 95% CI 1.35-1.52) and time-updated elevated potassium, but not a state of chronic hyperkalemia (HR 1.07, 95% CI 0.95-1.20), predicted the risk of death.

Conclusion

Chronic hyperkalemia occurs in 4-17% of patients with CKD G3-5. We did not observe a clear dose-response for the association between hyperkalemia pattern (normal, transient, chronic) with either MACE or death. There was modest incremental information in the previous potassium pattern, beyond potassium measured at a single time point.

FC 067WHEN TO INITIATE DIALYSIS TO REDUCE MORTALITY AND CARDIOVASCULAR EVENTS IN ADVANCED CKD: A NATIONWIDE COHORT STUDY

Background and Aims

There is currently no direct evidence to inform a specific glomerular filtration rate (GFR) to initiate maintenance dialysis. Previous studies are limited by the number of kidney function thresholds compared, immortal time or lead time biases, or small sample sizes. The only randomised trial (IDEAL) found no difference between early versus late start, but confidence intervals were wide.

Method

Nationwide observational cohort study using data from the Swedish Renal Registry between January 1, 2007 and December 31, 2016, with follow-up until June 1, 2017. Included individuals were receiving nephrologist care and had an eGFR between 10-20 ml/min/1.73m2. A randomized trial was emulated using the cloning, censoring and weighting method. Our primary analysis compared late (at an eGFR 5-7 ml/min/1.73m2 [eGFR5-7]), intermediate (eGFR7-10) and early (eGFR10-14) dialysis initiation to validate our analytical methods by comparison with IDEAL. Our secondary analysis compared fifteen dialysis initiation strategies with eGFR values ranging between 4 and 19 ml/min/1.73m2 in increments of 1 ml/min/1.73m2. Study outcomes were 5-year all-cause mortality and major adverse cardiovascular events (MACE; composite of cardiovascular death, non-fatal myocardial infarction and stroke). Adjusted hazard ratios [HR] and cumulative survival proportions were estimated using a dynamic marginal structural model.

Results

Among 10,290 individuals with advanced CKD (median age 73 years; 36% women; median eGFR 16.8 ml/min/1.73m2), 3725 individuals initiated dialysis, 4160 died and 2446 experienced MACE. In trial emulation, the 5-year mortality risk was 53.0% for eGFR5-7, 50.3% for eGFR7-10 and 49.7% for eGFR10-14. Compared with eGFR5-7, the 5-year absolute mortality risk difference was -2.7% (95% CI, -4.6% to -0.7%) for eGFR7-10 and -3.3% (95% CI, -5.2% to -1.3%) for eGFR10-14, with a HR of 0.97 (0.94-0.99) and 0.96 (0.94-0.99), respectively. The 5-year absolute MACE risk differences were -1.1% (95% CI, -3.8% to 2.1%) for eGFR7-10 and -3.6% (95% CI, -6.0% to -1.0%) for eGFR10-14 compared with eGFR5-7, with a HR of 1.00 (0.97-1.04) and 0.96 (0.97-1.00), respectively. When analysing fifteen eGFR thresholds, initiation at eGFR15-16 was associated with the largest reduction in mortality (absolute difference, -5.9% [95% CI, -8.0% to -3.1%]; HR, 0.88 [95% CI, 0.85-0.92]) and MACE (absolute difference, -4.5% [95% CI, -7.6% to -1.4%]; HR, 0.92 [95% CI, 0.89-0.97]), compared with eGFR4-5. This -5.9% absolute risk difference translates to a mean postponement of death of 1.8 months over 5-years of follow-up. However, dialysis would need to be initiated on average 14 months earlier.

Conclusion

Early dialysis initiation was associated with a modest reduction in mortality and cardiovascular events. Such a reduction may not outweigh the burden of longer dialysis treatment duration for the patient.

MO129COMPARATIVE EFFECTIVENESS OF SGLT2I VERSUS DPP4I ON CARDIOVASCULAR AND RENAL OUTCOMES IN ROUTINE-CARE SETTINGS

Background and Aims

While clinical trials have demonstrated the efficacy of SGLT2 inhibitors on preventing cardiovascular and renal damage, few studies have expanded this evidence to routine-care settings.

Method

We compared clinical outcomes of adults who started SGLT2i or DPP4i therapy in Stockholm, Sweden, during 2013-2019. The primary outcome was a composite of cardiovascular (CV) death and hospitalization for heart failure (HF). Secondary outcomes included major adverse cardiovascular events (MACE; composite of cardiovascular death, myocardial infarction, stroke), all-cause mortality and the rate of eGFR decline (eGFR slope). Propensity score weighted Cox regression was used to balance 55 variables and estimate intention-to-treat hazard ratios with 95% confidence intervals. Differences in eGFR slope were calculated with linear mixed models.

Results

We identified 7136 individuals starting SGLT2i and 13,618 starting DPP4i therapy. Median age was 64 years (37% women) and median eGFR 86 ml/min/1.73m2. During median follow-up of 2.1 years, 211 individuals developed the primary outcome, 269 experienced MACE and 178 died. After propensity score weighting, patients starting SGLT2i therapy were at lower risk for the composite of CV death/HF hospitalization (HR 0.71; 95% CI 0.53-0.94) compared with DPP4i, and showed a tendency towards lower MACE (0.84; 95% CI 0.67-1.04) and all-cause mortality (0.85; 95% CI 0.62-1.18). There were a median of 4 (interquartile range: 2-8) eGFR measurements during follow-up per patient to estimate their eGFR slopes. In adjusted models, new users of SGLT2i had a slower rate of kidney function decline compared with DPP4i (eGFR slope difference of 0.43 (95% CI 0.15-0.72) ml/min/1.73m2 per year). Results for the primary outcome were consistent across 7 pre-specified subgroups, including eGFR (eGFR ≥60: HR 0.79 [95% CI 0.57-1.08]; eGFR &lt;60: HR 0.62 [0.38-0.99], p-value for interaction 0.40).

Conclusion

In patients undergoing routine care, initiation of SGLT2i was associated with fewer cardiovascular outcomes and less rapid kidney function decline compared with DPP4i initiation.

Stopping Renin-Angiotensin System Inhibitors in Patients with Advanced CKD and Risk of Adverse Outcomes: A Nationwide Study

BACKGROUND

It is unknown whether stopping renin-angiotensin system (RAS) inhibitor therapy in patients with advanced CKD affects outcomes.

METHODS

We studied patients referred to nephrologist care, listed on the Swedish Renal Registry during 2007-2017, who developed advanced CKD (eGFR<30 ml/min per 1.73 m²) while on RAS inhibitor therapy. Using target trial emulation techniques on the basis of cloning, censoring, and weighting, we compared the risks of stopping within 6 months and remaining off treatment versus continuing RAS inhibitor therapy. These included risks of subsequent 5-year all-cause mortality, major adverse cardiovascular events, and initiation of kidney replacement therapy (KRT).

RESULTS

Of 10,254 prevalent RAS inhibitor users (median age 72 years, 36% female) with new-onset eGFR <30 ml/min per 1.73 m², 1553 (15%) stopped RAS inhibitor therapy within 6 months. Median eGFR was 23 ml/min per 1.73 m². Compared with continuing RAS inhibition, stopping this therapy was associated with a higher absolute 5-year risk of death (40.9% versus 54.5%) and major adverse cardiovascular events (47.6% versus 59.5%), but with a lower risk of KRT (36.1% versus 27.9%); these corresponded to absolute risk differences of 13.6 events per 100 patients, 11.9 events per 100 patients, and -8.3 events per 100 patients, respectively. Results were consistent whether patients stopped RAS inhibition at higher or lower eGFR, across prespecified subgroups, after adjustment and stratification for albuminuria and potassium, and when modeling RAS inhibition as a time-dependent exposure using a marginal structural model.

CONCLUSIONS

In this nationwide observational study of people with advanced CKD, stopping RAS inhibition was associated with higher absolute risks of mortality and major adverse cardiovascular events, but also with a lower absolute risk of initiating KRT.

Modifiable Lifestyle Factors for Primary Prevention of CKD: A Systematic Review and Meta-Analysis

BACKGROUND

Despite increasing incidence of CKD, no evidence-based lifestyle recommendations for CKD primary prevention apparently exist.

METHODS

To evaluate the consistency of evidence associating modifiable lifestyle factors and CKD incidence, we searched MEDLINE, Embase, CINAHL, and references from eligible studies from database inception through June 2019. We included cohort studies of adults without CKD at baseline that reported lifestyle exposures (diet, physical activity, alcohol consumption, and tobacco smoking). The primary outcome was incident CKD (eGFR<60 ml/min per 1.73 m²). Secondary outcomes included other CKD surrogate measures (RRT, GFR decline, and albuminuria).

RESULTS

We identified 104 studies of 2,755,719 participants with generally a low risk of bias. Higher dietary potassium intake associated with significantly decreased odds of CKD (odds ratio [OR], 0.78; 95% confidence interval [95% CI], 0.65 to 0.94), as did higher vegetable intake (OR, 0.79; 95% CI, 0.70 to 0.90); higher salt intake associated with significantly increased odds of CKD (OR, 1.21; 95% CI, 1.06 to 1.38). Being physically active versus sedentary associated with lower odds of CKD (OR, 0.82; 95% CI, 0.69 to 0.98). Current and former smokers had significantly increased odds of CKD compared with never smokers (OR, 1.18; 95% CI, 1.10 to 1.27). Compared with no consumption, moderate consumption of alcohol associated with reduced risk of CKD (relative risk, 0.86; 95% CI, 0.79 to 0.93). These associations were consistent, but evidence was predominantly of low to very low certainty. Results for secondary outcomes were consistent with the primary finding.

CONCLUSIONS

These findings identify modifiable lifestyle factors that consistently predict the incidence of CKD in the community and may inform both public health recommendations and clinical practice.

Comparative Effectiveness of Renin-Angiotensin System Inhibitors and Calcium Channel Blockers in Individuals With Advanced CKD: A Nationwide Observational Cohort Study

RATIONALE & OBJECTIVE

It is unknown whether initiating renin-angiotensin system (RAS) inhibitor therapy in patients with advanced chronic kidney disease (CKD) is superior to alternative antihypertensive agents such as calcium channel blockers (CCBs). We compared the risks for kidney replacement therapy (KRT), mortality, and major adverse cardiovascular events (MACE) in patients with advanced CKD in routine nephrology practice who were initiating either RAS inhibitor or CCB therapy.

STUDY DESIGN

Observational study in the Swedish Renal Registry, 2007 to 2017.

SETTINGS & PARTICIPANTS

2,458 new users of RAS inhibitors and 2,345 CCB users with estimated glomerular filtration rates<30mL/min/1.73m² (CKD G4-G5 without KRT) who were being followed up by a nephrologist. As a positive control cohort, new users of the same drugs with CKD G3 (estimated glomerular filtration rate, 30-60mL/min/1.73m²) were evaluated.

EXPOSURES

RAS inhibitor versus CCB therapy initiation.

OUTCOME

Initiation of KRT (maintenance dialysis or transplantation), all-cause mortality, and MACE (composite of cardiovascular death, myocardial infarction, or stroke).

ANALYTICAL APPROACH

HRs with 95% CIs were estimated using propensity score-weighted Cox proportional hazards regression adjusting for demographic, clinical, and laboratory covariates.

RESULTS

Median age was 74 years, 38% were women, and median follow-up was 4.1 years. After propensity score weighting, there was significantly lower risk for KRT after new use of RAS inhibitors compared with new use of CCBs (adjusted HR, 0.79 [95% CI, 0.69-0.89]) but similar risks for mortality (adjusted HR, 0.97 [95% CI, 0.88-1.07]) and MACE (adjusted HR, 1.00 [95% CI, 0.88-1.15]). Results were consistent across subgroups and in as-treated analyses. The positive control cohort of patients with CKD G3 showed similar KRT risk reduction (adjusted HR, 0.67 [95% CI, 0.56-0.80]) with RAS inhibitor therapy compared with CCBs.

LIMITATIONS

Potential confounding by indication.

CONCLUSIONS

Our findings provide evidence from real-world clinical practice that initiation of RAS inhibitor therapy compared with CCBs may confer kidney benefits among patients with advanced CKD, with similar cardiovascular protection.

Forgotten Technology in the COVID-19 Pandemic: Filtration Properties of Cloth and Cloth Masks-A Narrative Review

Management of the global crisis of the coronavirus disease 2019 pandemic requires detailed appraisal of evidence to support clear, actionable, and consistent public health messaging. The use of cloth masks for general public use is being debated, and is in flux. We searched the MEDLINE and EMBASE databases and Google for articles reporting the filtration properties of flat cloth or cloth masks. We reviewed the reference lists of relevant articles to identify further articles and identified articles through social and conventional news media. We found 25 articles. Study of protection for the wearer used healthy volunteers, or used a manikin wearing a mask, with airflow to simulate different breathing rates. Studies of protection of the environment, also known as source control, used convenience samples of healthy volunteers. The design and execution of the studies was generally rigorously described. Many descriptions of cloth lacked the detail required for reproducibility; no study provided all the expected details of material, thread count, weave, and weight. Some of the homemade mask designs were reproducible. Successful masks were made of muslin at 100 threads per inch (TPI) in 3 to 4 layers (4-layer muslin or a muslin-flannel-muslin sandwich), tea towels (also known as dish towels), made using 1 layer (2 layers would be expected to be better), and good-quality cotton T-shirts in 2 layers (with a stitched edge to prevent stretching). In flat-cloth experiments, linen tea towels, 600-TPI cotton in 2 layers, and 600-TPI cotton with 90-TPI flannel performed well but 80-TPI cotton in 2 layers did not. We therefore recommend cotton or flannel at least 100 TPI, at least 2 layers. More layers, 3 or 4, will provide increased filtration but there is a trade-off in that more layers increases the resistance to breathing. Although this is not a systematic review, we included all the articles that we identified in an unbiased way. We did not include gray literature or preprints. A plain language summary of these data and recommendations, as well as information on making, wearing and cleaning cloth masks is available at www.clothmasks.ca.

Acute hyperkalemia in the emergency department: a summary from a Kidney Disease: Improving Global Outcomes conference

Hyperkalemia is a common electrolyte disorder observed in the emergency department. It is often associated with underlying predisposing conditions, such as moderate or severe kidney disease, heart failure, diabetes mellitus, or significant tissue trauma. Additionally, medications, such as inhibitors of the renin-angiotensin-aldosterone system, potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs, succinylcholine, and digitalis, are associated with hyperkalemia. To this end, Kidney Disease: Improving Global Outcomes (KDIGO) convened a conference in 2018 to identify evidence and address controversies on potassium management in kidney disease. This review summarizes the deliberations and clinical guidance for the evaluation and management of acute hyperkalemia in this setting. The toxic effects of hyperkalemia on the cardiac conduction system are potentially lethal. The ECG is a mainstay in managing hyperkalemia. Membrane stabilization by calcium salts and potassium-shifting agents, such as insulin and salbutamol, is the cornerstone in the acute management of hyperkalemia. However, only dialysis, potassium-binding agents, and loop diuretics remove potassium from the body. Frequent reevaluation of potassium concentrations is recommended to assess treatment success and to monitor for recurrence of hyperkalemia.

Cloth Masks May Prevent Transmission of COVID-19: An Evidence-Based, Risk-Based Approach

As the COVID-19 pandemic progressed across the world, governments, international agencies, policymakers, and public health officials began recommending widespread use of nonmedical cloth masks to reduce the transmission of SARS-CoV-2. The authors of this article suggest that there is convincing evidence to support this recommendation.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

Purpose of review:

(1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients.

Sources of information:

The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

Methods:

The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions.

Key findings:

We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool.

Limitations:

The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

Stopping renin-angiotensin system blockers after acute kidney injury and risk of adverse outcomes: parallel population-based cohort studies in English and Swedish routine care

BACKGROUND

The safety of restarting angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) after acute kidney injury (AKI) is unclear. There is concern that previous users do not restart ACEI/ARB despite ongoing indications. We sought to determine the risk of adverse events after an episode of AKI, comparing prior ACEI/ARB users who stop treatment to those who continue.

METHODS

We conducted two parallel cohort studies in English and Swedish primary and secondary care, 2006-2016. We used multivariable Cox regression to estimate hazard ratios (HR) for hospital admission with heart failure (primary analysis), AKI, stroke, or death within 2 years after hospital discharge following a first AKI episode. We compared risks of admission between people who stopped ACEI/ARB treatment to those who were prescribed ACEI/ARB within 30 days of AKI discharge. We undertook sensitivity analyses, including propensity score-matched samples, to explore the robustness of our results.

RESULTS

In England, we included 7303 people with AKI hospitalisation following recent ACEI/ARB therapy for the primary analysis. Four thousand three (55%) were classified as stopping ACEI/ARB based on no prescription within 30 days of discharge. In Sweden, we included 1790 people, of whom 1235 (69%) stopped treatment. In England, no differences were seen in subsequent risk of heart failure (HR 1.10; 95% confidence intervals (CI) 0.93-1.30), AKI (HR 0.90; 95% CI 0.77-1.05), or stroke (HR 0.99; 95% CI 0.71-1.38), but there was an increased risk of death (HR 1.27; 95% CI 1.15-1.41) in those who stopped ACEI/ARB compared to those who continued. Results were similar in Sweden: no differences were seen in risk of heart failure (HR 0.91; 95% CI 0.73-1.13) or AKI (HR 0.81; 95% CI 0.54-1.21). However, no increased risk of death was seen (HR 0.94; 95% CI 0.78-1.13) and stroke was less common in people who stopped ACEI/ARB (HR 0.56; 95% CI 0.34-0.93). Results were similar across all sensitivity analyses.

CONCLUSIONS

Previous ACEI/ARB users who continued treatment after an episode of AKI did not have an increased risk of heart failure or subsequent AKI compared to those who stopped the drugs.

Plant-based diets to manage the risks and complications of chronic kidney disease

Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling, these restrictions can result in a low intake of fruits and vegetables and a lack of diversity in the diet. Plant nutrients and plant-based diets could have beneficial effects in patients with CKD: increased fibre intake shifts the gut microbiota towards reduced production of uraemic toxins; plant fats, particularly olive oil, have anti-atherogenic effects; plant anions might mitigate metabolic acidosis and slow CKD progression; and as plant phosphorus has a lower bioavailability than animal phosphorus, plant-based diets might enable better control of hyperphosphataemia. Current evidence suggests that promoting the adoption of plant-based diets has few risks but potential benefits for the primary prevention of CKD, as well as for delaying progression in patients with CKD G3-5. These diets might also help to manage and prevent some of the symptoms and metabolic complications of CKD. We suggest that restriction of plant foods as a strategy to prevent hyperkalaemia or undernutrition should be individualized to avoid depriving patients with CKD of these potential beneficial effects of plant-based diets. However, research is needed to address knowledge gaps, particularly regarding the relevance and extent of diet-induced hyperkalaemia in patients undergoing dialysis.

P0178COMPARATIVE EFFECTIVENESS OF RENIN-ANGIOTENSIN SYSTEM INHIBITORS AND CALCIUM CHANNEL BLOCKERS IN INDIVIDUALS WITH ADVANCED CHRONIC KIDNEY DISEASE: A NATIONWIDE COHORT STUDY

Background and Aims

There is a lack of data that could help to guide the choice of antihypertensive agents in patients with advanced chronic kidney disease (CKD). We evaluated whether initiating treatment with a renin-angiotensin system inhibitor (RASi) is superior to calcium channel blockers (CCB) in preventing mortality, major adverse cardiovascular events (MACE) or kidney replacement therapy (KRT) in patients with advanced CKD.

Method

Observational study from the Swedish Renal Register, 2007-2017. We identified all nephrologist-referred patients in Sweden who initiated RASi or CCB treatment and had non-dialysis dependent advanced CKD (eGFR &lt;30 ml/min/1.73m2). The associations between RASi vs CCB initiation, mortality, MACE and KRT were assessed by Cox regression. Analyses were adjusted with propensity score weighting for a wide range of confounders, including demographics, blood pressure, laboratory measures, comorbidities and medications. As a positive control we evaluated new use of the same drugs in patients with CKD G3 (N = 2608; eGFR between 30-60 ml/min/1.73m2). Furthermore subgroup, as-treated and competing risk analyses were performed.

Results

The propensity-score weighted cohort included 2479 RASi and 2327 CCB initiators who were well-matched for baseline confounders (all standardized differences &lt;0.1). Median follow-up was 4.1 years, with a maximum follow-up of over 10 years. Compared to CCB, initiation of RASi was associated with a similar risk of mortality (adjusted HR 0.94; 95% CI 0.85-1.03) and MACE (0.99; 0.87-1.13), but with a lower risk of KRT (0.87; 0.78-0.98). Results were consistent across subgroups, in as-treated analyses and after accounting for the competing risk of death. In the control cohort of patients with CKD G3, initiation of RASi (versus CCB) was associated with lower KRT risk (adjusted HR 0.67; 0.47-0.96), and similar risk of mortality (0.91; 0.76-1.08) and MACE (1.06; 0.82-1.35).

Conclusion

Compared with CCB, initiation of RASi in patients with advanced CKD was associated with a lower risk of KRT, but no different risk of mortality or MACE.

Association of Acute Increases in Plasma Creatinine after Renin-Angiotensin Blockade with Subsequent Outcomes

BACKGROUND AND OBJECTIVES

Data from observational and interventional studies provide discordant results regarding the relationship between creatinine increase after renin-angiotensin system inhibition (RASi) and adverse outcomes. We compared health outcomes among patients with different categories of increase in creatinine upon initiation of RASi in a large population-based cohort.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective analysis of the Stockholm CREAtinine Measurements database, which contains complete information on diagnoses, medication dispensation claims, and laboratory test results for all Stockholm citizens accessing health care. Included were 31,951 adults initiating RASi during 2007-2011 with available pre- and postinitiation creatinine monitoring. Multivariable Cox regression was used to compare mortality, cardiovascular and ESKD events among individuals with different ranges of creatinine increases within 2 months after starting treatment.

RESULTS

In a median follow-up of 3.5 years, acute increases in creatinine were associated with mortality (3202 events) in a graded manner: compared with creatinine increases <10%, a 10%-19% increase showed an adjusted hazard ratio (HR) of 1.15 (95% confidence interval [95% CI], 1.05 to 1.27); HR 1.22 (95% CI, 1.07 to 1.40) for 20%-29%; HR 1.55 (95% CI, 1.36 to 1.77) for ≥30%. Similar graded associations were present for heart failure (2275 events, P<0.001) and ESKD (52 events; P<0.001), and, less consistently, myocardial infarction (842 events, P=0.25). Results were robust across subgroups, among continuing users, when patients with decreases in creatinine were excluded from the reference group, and after accounting for death as a competing risk.

CONCLUSIONS

Among real-world monitored adults, increases in creatinine (>10%) after initiation of RASi are associated with worse health outcomes. These results do not address the issue of discontinuation of RASi when plasma creatinine increases but do suggest that patients with increases in creatinine have higher subsequent risk of cardiovascular and kidney outcomes.