A multicenter randomized controlled trial indicates that paclitaxel-coated balloons provide no benefit for arteriovenous fistulas.

The role of paclitaxel-coated balloons has been established in the coronary and peripheral arterial circulations with recent interest in the use of paclitaxel-coated balloons to improve patency rates following angioplasty of arteriovenous fistulas. To assess the efficacy of paclitaxel-coated angioplasty balloons to prolong the survival time of target lesion primary patency in arteriovenous fistulas, we designed an investigator-led multi-center randomized controlled trial with follow up time variable for a minimum of one year. Patients with an arteriovenous fistula who were undergoing an angioplasty for a clinical indication were included but patients with one or more lesions outside the treatment segment were excluded. Following successful treatment with a high-pressure balloon, 212 patients were randomized. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the control arm, an identical procedure was followed, but using a standard balloon. The primary endpoint was time to loss of clinically driven target lesion primary patency. Primary analysis showed no significant evidence for a difference in time to end of target lesion primary patency between groups: hazard ratio 1.18 with a 95% confidence interval of 0.78 to 1.79. There were no significant differences for any secondary outcomes, including patency outcomes and adverse events. Thus, our study demonstrated no evidence that paclitaxel-coated balloons provide benefit, following standard care high-pressure balloon angioplasty, in the treatment of arteriovenous fistulas. Hence, in view of the benefit suggested by other trials, the role of paclitaxel-coated angioplasty balloons remains uncertain.

NIMO-CKD-UK: a real-world, observational study of iron isomaltoside in patients with iron deficiency anaemia and chronic kidney disease.

BACKGROUND: Intravenous iron is often used to treat iron deficiency anaemia in non-dialysis chronic kidney disease (ND-CKD), but the optimal dosing regimen remains unclear. We evaluated the impact of high- versus low-dose intravenous iron isomaltoside on the probability of retreatment with intravenous iron in iron-deficient ND-CKD patients. METHODS: This real-world, prospective, observational study collected data from 256 ND-CKD patients treated for anaemia in the UK. Following an initial course of iron isomaltoside, patients were followed for ≥12 months. Iron dose and the need for retreatment were determined at the investigators' discretion. The primary study outcome was the need for retreatment at 52 weeks compared between patients who received >1000 mg of iron during Course 1 and those who received ≤1000 mg. Safety was evaluated through adverse drug reactions. RESULTS: The probability of retreatment at Week 52 was significantly lower in the >1000 mg iron group (n = 58) versus the ≤1000 mg group (n = 198); hazard ratio (95% confidence interval [CI]): 0.46 (0.20, 0.91); p = 0.012. Mean (95% CI) haemoglobin increased by 6.58 (4.94, 8.21) g/L in the ≤1000 mg group and by 10.59 (7.52, 13.66) g/L in the >1000 mg group (p = 0.024). Changes in other blood and iron parameters were not significantly different between the two groups. Administering >1000 mg of iron isomaltoside saved 8.6 appointments per 100 patients compared to ≤1000 mg. No serious adverse drug reactions were reported. Of the patients who received ≤1000 mg of iron in this study, 82.3% were eligible for a dose >1000 mg. CONCLUSIONS: The >1000 mg iron isomaltoside regimen reduced the probability of retreatment, achieved a greater haemoglobin response irrespective of erythropoiesis-stimulating agent treatment, and reduced the total number of appointments required, compared to the ≤1000 mg regimen. Many of the patients who received ≤1000 mg of iron were eligible for >1000 mg, indicating that there was considerable underdosing in this study. TRIAL REGISTRATION: ClinicalTrials.gov NCT02546154 , 10 September 2015.

Early Ultrasound Surveillance of Newly-Created Hemodialysis Arteriovenous Fistula.

Introduction: We assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomized controlled trial (RCT) evaluation of ultrasound-directed salvage intervention. Methods: Consenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF nonmaturation identified by logistic regression modeling. Results: Of 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those that did not mature. Wrist and elbow AVF nonmaturation could be optimally modeled from week 4 ultrasound parameters alone, but with only moderate positive predictive values (PPVs) (wrist, 60.6% [95% confidence interval, CI: 43.9-77.3]; elbow, 66.7% [48.9-84.4]). Moreover, 40 (70.2%) of the 57 AVFs that thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage procedures initiated by that scan's findings to alter overall maturation rates. Modeling of the early ultrasound characteristics could also predict primary patency failure at 6 months; however, that model performed poorly at predicting assisted primary failure (those AVFs that failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data. Conclusion: Early ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only very modest improvements in fistula patency. Power calculations suggest that an impractically large number of participants (>1700) would be required for formal RCT evaluation.

Doppler ultrasound surveillance of recently formed haemodialysis arteriovenous fistula: the SONAR observational cohort study.

Background: Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. Objective: To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency. Design: A prospective multicentre observational cohort study (the 'SONAR' study). Setting: Seventeen haemodialysis centres in the UK. Participants: Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. Intervention: Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings. Main outcome measures: Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months. Results: A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas' non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset (n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data. Conclusions: Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit. Trial Registration: This trial is registered as ISRCTN36033877 and ISRCTN17399438. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

For people with advanced kidney disease, haemodialysis is best provided by an 'arteriovenous fistula', which is created surgically by joining a vein onto an artery at the wrist or elbow. However, these take about 2 months to develop fully ('mature'), and as many as 3 out of 10 fail to do so. We asked whether we could use early ultrasound scanning of the fistula to identify those that are unlikely to mature. This would allow us to decide whether it would be practical to run a large, randomised trial to find out if using early ultrasound allows us to 'rescue' fistulas that would otherwise fail. We invited adults to undergo serial ultrasound scanning of their fistula in the first few weeks after it was created. We then analysed whether we could use the data from the early scans to identify those fistulas that were not going to mature by week 10. Of the 333 fistulas that were created, about two-thirds reached maturity by week 10. We found that an ultrasound scan 4 weeks after fistula creation could reliably identify those fistulas that were going to mature. However, of those fistulas predicted to fail, about one-third did eventually mature without further intervention, and even without knowing what the early scans showed, another third were successfully rescued by surgery or X-ray-guided treatment at a later stage. Performing an early ultrasound scan on a fistula can provide reassurance that it will mature and deliver trouble-free dialysis. However, because scans are poor at identifying fistulas that are unlikely to mature, we would not recommend their use to justify early surgery or X-ray-guided treatment in the expectation that this will improve outcomes.

Surveillance arterioveNous fistulAs using ultRasound (SONAR) trial in haemodialysis patients: a study protocol for a multicentre observational study.

INTRODUCTION: Arteriovenous fistulas (AVFs) are considered the best and safest modality for providing haemodialysis in patients with end-stage renal disease. Only 20% of UK centres achieve the recommended 80% target for achieving dialysis of the prevalent dialysis population via permanent access (as opposed to a central venous catheter). This is partly due to the relatively poor maturation rate of newly created fistulas, with as many as 50% of fistulas failing to mature.The Surveillance Of arterioveNous fistulAe using ultRasound study will examine whether a protocolised programme of Doppler ultrasound (US) surveillance can identify, early after creation, potentially correctable problems in those AVFs that subsequently fail to mature. METHODS AND ANALYSIS: This is a multicentre observational study that will assess newly created AVFs by Doppler US performed at 2, 4, 6 and 10 weeks after creation. The primary outcome measure will be primary fistula patency at week 10. Secondary outcome measures include: successful use of the fistula; clinical suitability for dialysis; creation of new fistula or radiological salvage; fistula thrombosis; secondary fistula patency rate and patient acceptability. ETHICS AND DISSEMINATION: The study has been approved by the Cambridgeshire and Hertfordshire Research Ethics Committee and by the Health Research Authority (REC 18/EE/0234). The results generated from this work will be published as open access, within 3 years of trial commencement. We will also present our findings at key national/international renal meetings, as well as support volunteers at renal patient groups to disseminate the trial outcome. TRIAL REGISTRATION NUMBER: ISRCTN36033877.

Outcomes of immunosuppression in IgA nephropathy based on the oxford classification.

Numerous studies have addressed the predictive value of pathology findings from the Oxford Classification. Whether this influences treatment choice has not been determined. We evaluated patients with IgA nephropathy who were immunosuppressed and correlated our findings with both clinical and histological features as per the Oxford Classification. This was a retrospective observational study of 45 patients who had biopsy-proven IgA nephropathy with a mean follow-up of 2.6 years. Primary outcomes were time to end-stage renal disease (ESRD) or a 50% rise in serum creatinine. Immunosuppression was not associated with lower hazards for both ESRD and 50% rise in serum creatinine. From the Oxford Classification, only T0 was associated with significantly lower hazards for ESRD [hazard ratio (HR), 0.067; confidence interval (CI) 0.01-0.58]. Patients who had crescents and/or necrotizing lesions on biopsy were more likely to be immunosuppressed (odds ratio 9.99; 95% CI 1.99-50.06, P = 0.005) but demonstrated a statistically nonsignificant higher hazard for both renal end points (HR, 1.61; CI 0.19-13.89). Such lesions were also associated with a higher incidence of hypertension (149 vs. 135 mm Hg) and greater proteinuria (2.7 vs. 1.9 g/day) at presentation. The use of the Oxford Classification did not aid decision-making with regard to the use of immunosuppression. Crescents and/or necrosis identified on histology were associated with the use of immunosuppression. Hence, there is a need for these lesions to be evaluated further in large cohorts and incorporated into future disease classifications.

Paclitaxel-coated balloon fistuloplasty versus plain balloon fistuloplasty only to preserve the patency of arteriovenous fistulae used for haemodialysis (PAVE): study protocol for a randomised controlled trial.

BACKGROUND: The initial therapy for a stenosis in an arteriovenous fistula used for haemodialysis is radiological balloon dilatation or angioplasty. The benefit of angioplasty is often short-lived, intervention-free survival is reported to be 40-50 % at 1 year. Previous small studies and observational data suggest that paclitaxel-coated balloons may be of benefit in improving outcomes after fistuloplasty of stenotic arteriovenous fistulae. METHODS/DESIGN: We have designed a multicentre, double-blind randomised controlled trial to test the superiority of paclitaxel-coated balloons for preventing restenosis after fistuloplasty in patients with a native arteriovenous fistula. Two hundred and eleven patients will be followed up for a minimum of 1 year. Inclusion criteria include a clinical indication for a fistuloplasty, an access circuit that is free of synthetic graft material or stents, and a residual stenosis of 30 % or less after plain balloon fistuloplasty. Exclusion criteria include a synchronous venous lesion in the same access circuit, location of the stenosis central to the thoracic inlet or a thrombosed access circuit at the time of treatment. The primary endpoint is time to end of target lesion primary patency. This is defined as a clinically-driven radiological or surgical re-intervention at the treatment segment, thrombosis that includes the treatment segment, or abandonment of the access circuit due to an inability to re-treat the treatment segment. Secondary endpoints include angiographic late lumen loss, time to end of access circuit cumulative patency, the total number of interventions, and quality of life. The trial is funded by the National Institute for Health Research. DISCUSSION: We anticipate that this trial will provide rigorous data that will determine the efficacy of additional paclitaxel-coated balloon fistuloplasty versus plain balloon fistuloplasty only to preserve the patency of arteriovenous fistulae used for haemodialysis. TRIAL REGISTRATION: ISRCTN14284759 . Registered on 28 October 2015.

Eating disorders should be considered in the differential diagnosis of patients presenting with acute kidney injury and electrolyte derangement.

We present a case of a 40-year-old woman with a history of ongoing anorexia nervosa and bulimia nervosa who has required multiple admissions to hospital for management of acute kidney injury (AKI) and electrolyte derangement. This case is of interest as recent studies have highlighted the significant prevalence of disordered eating and the major public health implications this may have. We discuss the unusual finding of hypercalcaemia in this case and address the investigation and management of AKI and electrolyte disturbance in a patient with anorexia and bulimia.

Atorvastatin inhibits autoreactive B cell activation and delays lupus development in New Zealand black/white F1 mice.

Systemic lupus erythematosus is a multisystem autoimmune disease characterized by a wide range of immunological abnormalities that underlie the loss of tolerance. In this study we show that administration of atorvastatin to lupus-prone NZB/W F(1) mice resulted in a significant reduction in serum IgG anti-dsDNA Abs and decreased proteinuria. Histologically, the treatment was associated with reduced glomerular Ig deposition and less glomerular injury. Disease improvement was paralleled by decreased expression of MHC class II on monocytes and B lymphocytes and reduced expression of CD80 and CD86 on B lymphocytes. Consequent upon this inhibition of Ag presentation, T cell proliferation was strongly impaired by atorvastatin in vitro and in vivo. A significant decrease in MHC class II expression was also observed in the target organ of lupus disease (i.e., the glomerulus). Serum cholesterol in atorvastatin-treated lupus mice fell to the level found in young NZB/W mice before disease onset. This is the first demonstration that atorvastatin can delay the progression of a spontaneous autoimmune disease and may specifically benefit patients with systemic lupus erythematosus.