Remote Surveillance Technology of Dialysis Arteriovenous Access: Retrospective Evaluation in a UK Renal Centre.

BACKGROUND: Early identification of dysfunctional arteriovenous haemodialysis (HD) vascular access (VA) is important for timely referral and intervention. METHOD: We retrospectively calculated VA risk score using Vasc-Alert surveillance software technology from HD treatment sessions in 2 satellite HD units over 18 months. We included in the analysis HD patients dialysing with arteriovenous fistula or graft (AVF/G) with available Vasc-Alert data for≥ 2 months. For group one (eventful) that included patients who developed vascular access thrombosis or stenosis over the study period, we collected Vasc-Alert risk score 2 months prior to the event and, for group two (uneventful), over 5 consecutive months. Vasc-Alert technology utilises routinely collected data during HD to calculate VA risk score and triggers an alert if the score is ≥7 in 3 consecutive dialysis sessions. Patients with >2 alerts (vascular access score ≥7) per month were considered to have positive alerts. RESULTS: From 140 HD patients, 81 patients dialysed via AVF/G. 77/81 had available Vasc-Alert data and were included in the final analysis. Out of 17 eventful patients, 11 (64.7%) had positive alerts 2 months prior to the vascular event. Out of the 60 patients without vascular events, 20 patients (33.3%) had positive alert. Vasc-Alert's sensitivity and specificity for vascular events were 64.7% and 66.6%, respectively. Within the 6 patients with thrombosed access, 2 patients (33.3%) detected by Vasc-Alert were not detected with clinical monitoring. CONCLUSION: Vascular access risk score can be a useful non-invasive vascular access surveillance method to assist clinical decision making.

A validation study of the kidney failure risk equation in advanced chronic kidney disease according to disease aetiology with evaluation of discrimination, calibration and clinical utility.

BACKGROUND: The Kidney Failure Risk Equation (KFRE) predicts the 2- and 5-year risk of end-stage renal disease (ESRD) in patients with chronic kidney disease (CKD) stages 3a-5. Its predictive performance in advanced CKD and in specific disease aetiologies requires further exploration. This study validates the 4- and 8-variable KFREs in an advanced CKD population in the United Kingdom by evaluating discrimination, calibration and clinical utility. METHODS: Patients enrolled in the Salford Kidney Study who were referred to the Advanced Kidney Care Service (AKCS) clinic at Salford Royal NHS Foundation Trust between 2011 and 2018 were included. The 4- and 8-variable KFREs were calculated on the first AKCS visit and the observed events of ESRD (dialysis or pre-emptive transplantation) within 2- and 5-years were the primary outcome. The area under the receiver operator characteristic curve (AUC) and calibration plots were used to evaluate discrimination and calibration respectively in the whole cohort and in specific disease aetiologies: diabetic nephropathy, hypertensive nephropathy, glomerulonephritis, autosomal dominant polycystic kidney disease (ADPKD) and other diseases. Clinical utility was assessed with decision curve analyses, comparing the net benefit of using the KFREs against estimated glomerular filtration rate (eGFR) cut-offs of < 20 ml/min/1.73m2 and < 15 ml/min/1.73m2 to guide further treatment. RESULTS: A total of 743 patients comprised the 2-year analysis and 613 patients were in the 5-year analysis. Discrimination was good in the whole cohort: the 4-variable KFRE had an AUC of 0.796 (95% confidence interval [CI] 0.762-0.831) for predicting ESRD at 2-years and 0.773 (95% CI 0.736-0.810) at 5-years, and there was good-to-excellent discrimination across disease aetiologies. Calibration plots revealed underestimation of risk at 2-years and overestimation of risk at 5-years, especially in high-risk patients. There was, however, underestimation of risk in patients with ADPKD for all KFRE calculations. The predictive accuracy was similar between the 4- and 8-variable KFREs. Finally, compared to eGFR-based thresholds, the KFRE was the optimal tool to guide further care based on decision curve analyses. CONCLUSIONS: The 4- and 8-variable KFREs demonstrate adequate discrimination and calibration for predicting ESRD in an advanced CKD population and, importantly, can provide better clinical utility than using an eGFR-based strategy to inform decision-making.

Lanthanum carbonate--a first line phosphate binder?

Hyperphosphatemia is associated with increased morbidity and mortality in dialysis patients. Oral phosphate binders are necessary to control serum phosphate in patients eating a normal diet and undergoing peritoneal dialysis or thrice weekly hemodialysis. Until recently, none of the available drugs came close to the model of an ideal oral binder, which would demonstrate high affinity, rapid binding regardless of pH, low solubility and absorption, lack of toxicity, palatability, and reasonable cost. Lanthanum carbonate is a safe and effective binder with data demonstrating no toxic effects after continuous exposure up to 6 years. Suggestions that absorption and accumulation of lanthanum is significant and of clinical importance do not stand up to close scrutiny and recommended it as a first line treatment for dialysis patients, particularly if they have evidence of vascular calcification.

Recurrence of hemolytic uremic syndrome after live related renal transplantation associated with subsequent de novo disease in the donor.

There is a significant risk of disease recurrence in patients with nondiarrheal (D-) hemolytic uremic syndrome (HUS) undergoing renal transplantation. Recent studies have found that approximately 20% of sporadic cases of HUS have mutations in the gene for the complement regulatory protein factor H. The authors report on 2 families, in each of which a family member initially presented with sporadic HUS and subsequently received a live-related renal transplant, one from a sibling and the other from the father. Subsequently, both recipients suffered recurrent HUS in the allograft, and both donors had HUS within a year of the transplant. Neither family has a factor H mutation. This report underlines the risk of disease recurrence in recipients associated with live-related renal transplantation in HUS and also suggests that the donors may be at risk.

Anaemia management and cardiomyopathy in renal failure.

Patients with renal failure are at great cardiovascular risk, with attributable death rates 10-20 times those of an age-matched population. Most patients develop cardiomyopathy, with a continuum of left ventricular dilation (LV), hypertrophy and systolic dysfunction. Untreated, these conditions predispose to cardiac failure, a dominant and highly lethal cardiovascular syndrome in this population. Several prospective observational studies have demonstrated anaemia to be an independent risk factor for each step in the process: haemodynamic overload, maladaptive LV enlargement, LV burn-out and death. Recent evidence suggests that physiological haemoglobin targets (e.g. >12 g/dl) may be optimal for maintaining cardiac health and quality of life, especially in patients without pre-existing clinical cardiac disease. Ongoing studies should determine whether a physiologically targeted approach to anaemia management reduces the burden of cardiomyopathy in renal failure.