Vascular Access Events Research Articles

#2559 “Remote software technology to assist clinical decision in vascular access surveillance: single UK centre experience”

Abstract Background and Aims Optimal arteriovenous access monitoring and surveillance aims for early detection of dysfunctional access, enabling pre-emptive referral for angioplasty or surgery to prevent access loss or thrombosis. Here we compared the addition of remote software surveillance to standard clinical care in our units. Method From January–December 2023 we conducted a 12-month prospective study of maintenance hemodialysis (HD) patients. We used Vasc-Alert software technology to assist clinical decision making for vascular access (VA) surveillance in 2 out of 5 HD units. In these units, vascular access risk score was calculated using Vasc-Alert software platform from routinely collected data from the dialysis procedure as previously described [1]. Patients with high Vasc-Alert access risk score (≥7) underwent clinical assessment and were referred for fistulogram if they met the relevant KDOQI criteria [2]. The following variables were collected from all 5 HD units: baseline permanent VA prevalence, subsequent VA events (stenosis or thrombosis), access abandonment (i.e. unsalvageable access loss), complication free days (CFD)-extended over one year (defined as days without serious vascular access events, radiological or surgical intervention, VA infection, hospitalisation or use of central venous catheter). Data was collected on patients who were pre-emptively referred for diagnostic fistulogram ± angioplasty but thrombosed while awaiting intervention. Median time interval from the date of fistulogram request till the date of confirmed thrombosed access was calculated. Comparison between HD units with Vasc-Alert use (Group 1) or without (Group 2) was performed using appropriate statistical tests depending on the type and distribution of the data. Survival analysis of post-intervention primary patency rate was conducted at 3 and 6 months defined as the time from the index procedure until the next access thrombosis or reintervention [3]. Results There were 81 (53.6%) patients with permanent VA in group 1and 201 (59.3%) patients in group 2at the start of the study. We recorded 23 (28.4%) episodes of stenosis and 6 (7.4%) episodes of thrombosis in Group 1 and 40 (19.9%) episodes of stenosis and 21 (10.4%) episodes of thrombosis in Group 2 (p value 0.121 and 0.432, respectively). In Group 2, 11 patients (5.5%) developed repeated stenosis and 2 patients (1%) repeated thrombosis. In Group 1, 5 /6 (83%) cases preemptively referred for diagnostic fistulogram ± angioplasty developed thrombosis whilst awaiting elective intervention, compared with 4/21 (19%) in group 2 (p value = 0.008) (Fig. 1). The median time interval from the date of fistulogram request till date of thrombosed VA was 26 days with Interquartile range (IQR 25-75%) of 21-34 days. Group 1 had better post-intervention primary patency rate of VA (Fig. 2) and longer CFD-extended compared to group 2 (p values < 0.001 and 0.002 respectively) (Table 1). Conclusion Our study shows that integrating Vasc-Alert technology into the VA surveillance program was associated with improved early detection of high-risk access, higher primary patency rates and CFD-extended. Additionally, our data emphasizes the need to enhance interventional radiology capacity for timely access intervention, to realise the true potential of Vasc-Alert technology in prevent access thrombosis.

Randomized Controlled Clinical Trial of the Effect of Treatment with Vitamin K2 on Vascular Calcification in Hemodialysis Patients (Trevasc-HDK)

Vitamin K deficiency among patients on hemodialysis (HD) affects the function of matrix GLA protein (MGP), a potent vitamin K-dependent inhibitor of vascular calcification (VC). We conducted a single-center randomized controlled trial (RCT) on maintenance HD patients to examine if vitamin K2 supplementation can reduce progression of coronary artery calcification (CAC) over an 18-month study period. Patients were randomized to vitamin K2 group receiving menaquinone-7360 μg 3 times/wk or control group. The primary outcome was CAC scores at the end of the study period. The secondary outcomes were aortic valve calcification (AVC), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx), dephosphorylated undercarboxylated MGP (dp-ucMGP) levels, major adverse cardiac events (MACE), and vascular access events. Of the 178 patients randomized, follow-up was completed for 138 patients. The CAC scores between the 2 groups were not statistically different at the end of 18 months (relative mean difference [RMD] 0.85, 95% CI 0.55-1.31). The secondary outcomes did not differ significantly in AVC (RMD 0.82, 95% CI 0.34-1.98), cfPWV (absolute mean difference [AMD] 0.55, 95% CI-0.50 to 1.60), and AIx (AMD 0.13, 95% CI-3.55 to 3.80). Supplementation with vitamin K2 did reduce dp-ucMGP levels (AMD-86, 95% CI-854 to-117). The composite outcome of MACE and mortality was not statistically different between the 2 groups (Hazard ratio= 0.98, 95% CI 0.50-1.94). Our study did not demonstrate a beneficial effect of vitamin K2 in reducing progression of VC in this population at the studied dose and duration.

#5089 EVALUATION OF REMOTE MONITORING OF HAEMODIALYSIS VASCULAR ACCESS FOR PREDICTION OF STENOSIS AND THROMBOTIC VASCULAR EVENTS

Abstract Background and Aims Early identification of dysfunctional arteriovenous haemodialysis (HD) vascular access (VA) is important for timely referral and intervention. We evaluated the accuracy of remote monitoring technology of VA that uses access flow data routinely collected during HD treatment to predict stenotic/thrombotic vascular events. Method We retrospectively calculated access risk score in a blinded fashion using Vasc-Alert vascular access surveillance technology from all HD treatments sessions in 2 satellite HD units for 12 months. We included in the analysis HD patients dialysing with arteriovenous fistula or graft with available Vascalert data for ≥ 2 months. The Access Risk Score was calculated as average of the scores for every 3 consecutive HD treatments and a high-risk score (HRS) was defined as ≥ 7.1 Using the electronic patient records, we identified patients with significant vascular access events (thrombosis, angiographic stenosis requiring angioplasty or doppler with > 50% stenosis) and without vascular access event. Information for clinically detected malfunctioning fistula was retrieved from the last clinic letter and the last vascular access multidisciplinary meeting notes prior to the vascular event. For the event positive patients, we included in the analysis the Vasc-alert data 2 months prior to the event. For the negative group, we included Vasc-alert data for 5 consecutive months with 1 month follow up. For the analysis we considered HRS positive if ≥2 HRS were generated. Results Out of 141 patients with available Vasc-alert data there were 60 patients dialyzing via a tunneled line. Amongst 81 patients with arteriovenous fistula or graft, 58 had available Vasc-alert data for ≥ 2 months. Out of 12 event positive patients (4 patients with thrombosed access, 6 patients with stenosis requiring angioplasty and 2 patients with >50% on doppler referred and awaiting fistulogram),10 (83%) had ≥2 HRS generated 2 months prior to the vascular event (Median 8, IQR 6.75-8). Out of the 46 patients without vascular events, 15 patients (32.6%) had HRS ≥ 2 and 4 patients had only one HRS score. Patient characteristics by vascular event are presented in Table 1. The sensitivity and specificity of HRS ≥2 for detecting future vascular events were 83.3% and 67.4%, respectively. The positive and negative predictive value of HRS ≥2 was 40% and 93.9% respectively. History of prior access stenosis and clinically detected malfunctioning fistula were significantly associated with vascular access events (P value 0.002, < 0.001 respectively), and HRS≥2 discrete values (P value 0.007 and 0.005 respectively). Within the patients with thrombosed access, 2 patients (50%) detected by HRS were not detected with clinical monitoring. Conclusion Our results suggest that vascular access risk score can be a useful screening tool to assist clinical decision making for VA risk stratification. Prospective studies are required to evaluate its utility in the VA surveillance pathway.

#5014 VALIDATION AND APPLICABILITY OF A MONITORING SYSTEM FOR VASCULAR ACCESS IN HAEMODIALYSIS: A MULTICENTRE STUDY

Abstract Background and Aims Routine systems for monitoring vascular access (VA) performance are lacking. We recently showed that with a VA triage system it is possible to improve the average value of a number of VA efficiency parameters and that the VA triage score was associated with clinical outcomes. The triage categorization is generated monthly by a scoring system which is based on a number of parameters (blood flows, VA pressure values, end HD circuit clots and a dedicated score of the external VA examination, KT/V) recorded at each session by the staff on a dedicate electronic spreadsheet. According to threshold values, triage classified each VA in Green (G), Yellow (Y) or Red (R), thus indicating the VA performance and the clinical risk of complication linked to VA. In our open label single centre study, with three years of follow-up, the average VA score improved significantly and G VA associated with lower mortality, compared to the Y and R VA. Aims: To validate the ability of the triage system to early identify VA with increased risk of complications. Methods In this interventional prospective, blinded multicentre study, each centre used the VA triage electronic spreadsheet without knowledge of the generated triage. After six months of system implementation, two years of follow-up (01/01/2020 - 01/12/2021) were planned to record VA related events. Two external reviewers evaluated the records. A minimum of three months VA follow up was necessary for patients enrolment. Results From 18 HD centres we enrolled 757 patients, aged 64,5±15,5 y.o.; 27% diabetics; HD since 24,4±32,4 months; 369 (48,7%) with arteriovenous fistula (AVF) and 388 (51,3%) with permanent central venous catheter (CVC). During 11,4±5,6 months of follow-up (range 3-23), 108537 HD sessions were recorded on the triage electronic spreadsheet, with 214 total clinical events and an event free time of 224,5 ±172 days (range 4-713). The VA related events were 150 (70,1%) during 16,3±2,2 months of follow up (range 3-23) with an event free time of 230±160 days (range 11-713). The VA Triage was: 60% Green, 35% Yellow and 5% Red. In the 369 patients with AVF the VA Triage was: 61% Green, 36% Yellow and 3% Red; The AVF Triage Green group showed: lower incidence of VA related events respect to the AVF Triage Yellow and Red group (30% vs 48%; P: 0.05); higher time-free from VA events (AVF Green vs AVF Yellow-Red: log-rank test: 0.04). Similar results were confirmed in the CVC groups: VA events incidence Triage Green 15% vs Triage Yellow-Red 40% (p: 0.001; time-free from VA events log-rank Test 0.001). Conclusion Our VA triage system identifies 40% of vascular accesses as yellow-red triage. These VA were not identified as at elevated clinical risk by the dialysis staff and only the Triage system was able to highlight them as critical. Notably the VA access with Yellow and Red Triage independently from the VA typology had an higher risk of clinical complications that according to the time survival curve could be detectable roughly 237,8 days before the event developed. The Triage system was able to identify early the VA with increased clinical risk and it may be a useful tool to prevent VA complication.

The association of long-term blood pressure variability with hemodialysis access thrombosis.

BackgroundBlood pressure variability (BPV) is an important risk factor for cardiovascular events in hemodialysis patients. We sought to determine the impact of BPV on hemodialysis access thrombosis.MethodsWe enrolled 1,011 prevalent hemodialysis patients from 12 hemodialysis centers since January 2018 and followed them until December 2020. Predialysis blood pressure (BP) was assessed at 12-week intervals. The coefficient of variation derived from 36 consecutive BP measurements was used as the metric for variability. The primary outcome was incident hemodialysis access thrombosis. Linear regression models were used to assess factors associated with BPV at baseline. Kaplan-Meier curves of the time until vascular access events were drawn and log-rank tests were calculated. Cox proportional hazards models were performed to assess the association of BPV with incident vascular access events.ResultsThe average coefficient of variance for systolic BPV was 10.9%. BPV was associated with age, body mass index, mean BP, diabetes, coronary and peripheral artery disease, history of access dysfunction, graft access, intradialytic hypotension, and use of antihypertensive medications. There were 194 access thrombosis events and 451 access stenosis events during a median follow-up period of 30 months. After adjustment of potential confounding factors, BPV was associated with increased risk of access thrombosis [hazard ratio = 1.27, 95% confidence interval (CI), 1.18–1.44, per 1 standard deviation increase in BPV]. The patients in the highest BPV quartile had 2.45 times the risk of thrombosis (CI, 1.62–3.70). The association was independent of average BP, intradialytic hypotension, and comorbidities. Similar trends of association were found in the subgroups analyzed. Comparative analysis using a time-varying variable model and different metrics of BPV showed consistent results.ConclusionOur findings underscored the impact of BP fluctuation on vascular access thrombosis.

MO792: Validation and Applicability of an Innovative Monitoring System for Vascular Access in Haemodialysis—A Multicentre Study

Abstract BACKGROUND AND AIMS Routine systems for monitoring vascular access (VA) performance are lacking. We recently showed that with a VA triage system it is possible to improve the average value of a number of HD efficiency parameters and that the triage score was associated with clinical outcomes [1]. The triage categorization is generated monthly by a scoring system which is based on a number of parameters (blood flows, VA pressure values, end HD circuit clots and a dedicated score of the external VA examination) recorded at each session by the staff and by the KT/V value recorded once every month. According to threshold values, each VA is classified as Green (G), Yellow (Y) or Red (R), thus attracting the attention of the staff. In our open-label single centre study, with 3 years of follow-up, the average VA scores improved significantly and G VA associated with lower mortality, compared to the Y and R VA. To validate our triage system with a multicentre, blinded approach in a large number of patients. The primary outcome was to evaluate if the triage identifies VA with an increased rate of complications; the secondary outcome was to verify the association of G VA score with better clinical outcomes. METHOD In this interventional prospective multicentre study, each centre used the electronic spreadsheet without knowledge of the generated score and triage. After 6 months of system implementation, 2 years of follow-up (1 January 2020–1 December 2021) were planned to record VA-related events. Two external reviewers evaluated the records. A minimum of 3 months VA follow-up was necessary for patients’ enrolment. RESULTS From 18 HD centres we enrolled 757 patients, aged 64.5 ± 15.5 years; x/y M/F; 27% diabetics; HD since 24.4 ± 32.4 months; 369 (48.7%) with arteriovenous fistula (AVF) and 388 (51.3%) with permanent central venous catheter (CVC). During 11.4 ± 5.6 months of follow-up (range 3–23), 108 537 HD sessions were recorded on the triage electronic spreadsheet, with 214 total clinical events and an event-free time of 224.5 ± 172 days (range 4–713). The VA-related events were 150 (70.1%) with an event-free time of 230 ± 160 days (range 11–713). As of today, we have the association of VA triage with VA events in a subgroup of 300 patients (66.1 ± 11.7 years; HD vintage 28 ± 18; diabetes 27.6%; 180 with AVF and 120 had CVC) who are not different from the remaining 457. In this subgroup, 54% had G VA triage, 39% Y and 7% R. In the subgroups distinguished by VA type, AVF cases (64.5 ± 12.1 years; HD since 30.3 ± 27.2; 24.4% diabetics) were triaged as G in 54%, Y in 41% and R in 5%, while CVC cases (66.5 ± 11.7 years; HD since 28.8 ± 36.5 months; 34.3% diabetics) were G in 54%, Y in 34% and R in 11%. 83 patients had VA-related events VA during 16.3 ± 2.2 months of follow-up (range 3–23), with an event-free time of 237.8 ± 195.9 days. Figure 1 shows how both AVF and CVC patients, stratified into only two triage groups (G versus Y and R together) according to their average triage, had significantly different time-free from events, which was higher in both populations (AVF P = 0.04; CVC P = 0.001) in the green triage groups. CONCLUSION Our VA triage system identifies 40% of vascular accesses as yellow-red triage, thus deserving clinical surveillance. This score has increased the rate of clinical complications which, according to the time survival curve could be detectable roughly 237.8 days before the event developed.

Association of Frailty With Thrombosis of Hemodialysis Vascular Access: A Prospective Taiwanese Cohort Study

Frailty, a multidimensional construct, has been associated with poor outcomes in patients receiving maintenance dialysis. This study assessed the association of frailty with dialysis vascular access patency. Multicenter prospective cohort study. 761 prevalent patients receiving hemodialysis at 9 centers in Taiwan as of January2018. Performance-based frailty was defined as 3 of the following: unintentional weight loss, weakness, exhaustion, low physical activity, and slow gait speed. Patients were categorized as prefrail if they had 1 or 2 of these characteristics. Rate of and time to dialysis access thrombosis. Data regarding vascular access events were collected for 30 months after enrollment through December 31,2020. Logistic regression analysis was used to estimate the association of clinical characteristics with frailty. Cox proportional hazards regression analysis was used to estimate the association of frailty with vascular access thrombosis adjusted for known clinical risk factors. The patients' mean age was 66 years, 46% were female, 18% had synthetic graft accesses, and 82% arteriovenous fistulas. Overall, 31% were frail, 35% were prefrail, and 34% were not frail. The frailty phenotype was associated with age, female sex, low body mass index, diabetes mellitus, and prior stroke. During a median follow-up of 731 days, 161 patients (21%) had access thrombosis events (not frail, 14%; prefrail, 20%; frail, 30%; P < 0.001). Frail patients had a higher risk of vascular access thrombosis than nonfrail patients (HR, 2.31 [95% CI, 1.55-3.39], P< 0.001). After multivariable adjustment for age and comorbidities, frailty remained significantly associated with access thrombosis for both fistulas and grafts. Limited generalizability and potential residual confounding. Frailty is associated with an increased risk of vascular access thrombosis. These findings highlight the risks of access failure experienced by frail patients receiving hemodialysis.

The Impact of Frailty on the Outcomes of Hemodialysis Vascular Access.

Frailty has been associated with mortality and adverse cardiovascular outcomes in patients with hemodialysis (HD), however the relevance of frailty on the outcomes of HD vascular access remains unclear. We enrolled a cohort of patients with prevalent HD between August 2018 and November 2018. The presence of 5 frailty phenotypes was determined at enrollment, using the modified Fried's criteria. Data regarding vascular access events or mortality were linked to prospectively collected data up to 24 months after enrollment. Of the 382 patients screened, 313 were recruited in the final analysis. The participants' mean age was 66 years, and 42.5% were female. Among all participants, 40.3% were determined to be frail and 29.4% pre-frail. The frail phenotype was associated with age, female gender, lower body mass index, unemployment, lower education level, and higher dialysis clearance. During the follow-up period (median, 24 months), 112 patients had vascular access events (non-frail, 27.4%; pre-frail, 35.9%; frail, 46.1%; p = 0.003) and 45 patients experienced thrombosis of the vascular access (non-frail, 4.2%; pre-frail, 9.8%; frail, 18.3%; p = 0.002). Cox regression analysis showed that frail patients had a 2.2-fold higher risk of experiencing vascular access events than non-frail patients [hazard ratio (HR): 2.205, 95% confidence interval (CI): 1.377-3.532, p = 0.001], but the association was not significant (HR: 1.634, 95% CI: 0.938-2.848, p = 0.082) after multivariate adjustment. The frail phenotype is common in Taiwanese patients who undergo maintenance HD and is associated with adverse outcomes of dialysis vascular access.

Validation of a vascular access specific quality of life measure (VASQoL).

A self-administered 11 item vascular access specific quality of life measure (VASQoL) was previously derived from detailed qualitative interviews with adult patients with kidney failure who have experienced vascular access using the Capabilities Approach as a theoretical base. This study reports the psychometric validation of the VASQoL measure including its reliability, content validity and responsiveness to change. Cognitive interviews were conducted with 23 adult patients with kidney failure after completion of the VASQoL measure. Focus group discussion with a vascular access professional multidisciplinary team was undertaken (n = 8) and subsequently a further 101 adult kidney failure patients with vascular access (TCVC, AVF or AVG) completed the digital VASQoL measure, EQ-5D and SF-36 questionnaires in a longitudinal study with prospectively recorded vascular access events. Transcript analysis of cognitive interviews after VASQoL completion indicated that the content was comprehensive and well understood by participants. Assessment of Internal reliability for the VASQoL measure was high (Cronbach's alpha 0.858). Test-retest reliability of the overall VASQoL measure was high (intra class correlation coefficient 0.916). In those patients who experienced a vascular access event, significant differences were observed in paired analysis of the VASQoL physical domain questions and vascular access function domain questions and in the EQ-5D usual activities, pain and anxiety domains. In those with no vascular access event, variation was observed in longitudinal analysis in VASQoL questions relating to worry about VA function and capability domains, whilst no variation was observed in the EQ5D measure. The VASQoL measure has good internal consistency, test-retest reliability, convergent validity and responsiveness to change for clinically relevant vascular access outcomes. This provides a validated, vascular access specific quality of life measure that can be used in future trials of vascular access, evaluation of new technologies and routine use as a patient reported outcome measure (PROM).

Evaluating outcomes of same-day discharge after catheter ablation for atrial fibrillation in a real-world cohort.

BackgroundAs same-day discharge (SDD) after catheter ablation (CA) for atrial fibrillation (AF) is increasingly utilized, it is important to further investigate this approach.ObjectiveTo investigate the safety and efficacy of SDD after CA for AF in a large nationwide administrative sample.MethodsThe IBM MarketScan Commercial Claims and Encounters database was used to identify adult patients under 65 years undergoing CA for AF (2016–2020). Eligible patients were indexed to date of first CA and classified into SDD or overnight stay (ONS) groups based on length of service. A 1:3 propensity score matching was used to create comparable SDD:ONS samples. Study outcomes were CA-related complications within 30 days after index procedure and AF recurrence within 1 year. Cox proportional hazards models were estimated for outcome comparison.ResultsIn the postmatch 30-day cohort, there were 1610 SDD and 4637 ONS patients with mean age 56.1 (± 7.6) years. There was no significant difference in composite 30-day postprocedural complication rate between SDD and ONS groups (2.7% vs 2.8%, respectively; P = .884). The most common complications were cerebrovascular events (0.7% vs 0.7%; P = .948), vascular access events (0.6% vs 0.6%; P = .935), and pericardial complications (0.6% vs 0.5%; P = .921). Further, no significant difference in composite AF recurrence rate at 1 year was observed among SDD and ONS groups (10.2% vs 8.8%; hazard ratio = 1.167; 95% confidence interval 0.935–1.455; P = .172).ConclusionIn a large, propensity-matched, real-world sample, SDD appears to be safe and have similar outcomes compared with overnight observation following CA for AF.

Impact of incremental versus conventional initiation of haemodialysis on residual kidney function: study protocol for a multicentre feasibility randomised controlled trial

IntroductionPreserving residual kidney function (RKF) may be beneficial to patients on haemodialysis (HD) and it has been proposed that commencing dialysis incrementally rather than three times a week may preserve...

P1248DOES INCREMENTAL HAEMODIALYSIS PRESERVE NATIVE KIDNEY FUNCTION? A MULTI-CENTRE FEASIBILITY RANDOMISED CONTROL TRIAL

Abstract Background and Aims Incremental HD is a method of individualising haemodialysis (HD) dose according to level of residual renal function(RRF) such that as RRF reduces, HD dose is upwardly adjusted. Retrospective data suggest potential benefit of this approach in preserving RRF, a key predictor of survival for dialysis patients. Method A randomised, intention-to-treat, multi-centre trial was designed to determine the feasibility of a future definitive trial of incremental HD to establish if this approach preserves RRF. The trial was designed to estimate effect size of potential benefit in terms of RRF. 55 patients with RRF urea clearance≥3ml/min/1.73m2 BSA and within 3 months of starting HD were randomised across 4 UK dialysis centres to either conventional 3x weekly HD for 3.5-4 hours or incremental HD. The incremental HD protocol involved initiation of HD 2x weekly after randomization and upward adjustment of HD frequency and time as RRF was lost. In the conventional HD arm, patients were dialysed to ensure Standard Kt/VDialysis&amp;gt;2.0. In the incremental HD arm, patients were dialysed to ensure Standard Kt/VDialysis+Standard Kt/VResidual Renal Function&amp;gt;2.0 so both groups were dialysed to the same urea clearance target, except that urea clearance incorporated RRF in the incremental HD arm. Follow up was for 6 months (primary outcome data) but secondary outcome data will be for 12m. Patients were withdrawn for transplant, dialysis modality change or for patient choice. The primary outcome was rate of change of RRF in the first 6 months after randomization (effect size of intervention). Recruitability, retainability, protocol adherence and rate of adverse events were also measured as a primary objective. As a secondary outcome, we determined proportion of patients with urea clearance≥2 and ≥3ml/min /1.73m2 BSA at the 6 month time point. Impact of dialysis treatment was measured using questionnaire-based assessments at baseline and 6 months. Results 26 patients were randomised to standard HD and 29 to incremental HD. Baseline demographics including age, weight, haemoglobin, blood pressure, Charleson Comorbidity Index, were not significantly different between study arms. Baseline residual renal urea clearance was 5.1 ± SD 1.8 ml/min/1.73m2 BSA in the standard HD arm and 5.72 ± SD 2.49 in the incremental HD arm. 6 months, residual renal urea clearance reduced to 2.68±SD 1.73 in the standard HD arm and 3.80±SD 1.85 in the incremental arm. In the first 6 months, 3 patients recovered to dialysis independence (standard arm=1, incremental arm=2). Slope of RRF was not significantly different between two arms (p=0.39). The proportion of patients with significant urea clearance&amp;gt;2ml/min/1.73m2 BSA at 6 months was significantly higher in the incremental HD arm (92%) compared to the standard HD arm (65%), p=0.032. Rate of major adverse cardiac events, fluid overload, hyperkalaemia, vascular access events, deaths and infections did not differ significantly between groups. There were 2 deaths in the standard HD arm (in 4025 patient days) versus 1 in the incremental HD arm in the first 6 months(4666 patient days). There was no significant difference in Clinical Frailty Score, Montreal Cognitive Assessment score, depression score (PHQ-9), Quality of Life (EQ-5D-5L) and Illness Intrusiveness Rating Scale between groups at baseline and 6m time points. Conclusion Rate of loss of RRF (slope) was not significantly different between incremental HD and standard HD arms but incremental HD was associated with significantly higher probability of retaining urea clearance&amp;gt;2ml/min/1.73m2. There was no evidence of any clinical detrimental effect of incremental HD in terms of mortality, fluid overload or hyperkalaemic events. Incremental HD does not appear to be harmful and may confer a small benefit to preservation of residual renal function. A definitive study is required to define clinical benefits further.

The effect of extended‐hours hemodialysis on outcomes: A systematic review and meta‐analysis

Extended-hours hemodialysis is associated with improvements in quality of life (QoL) and mortality, but it may accelerate the loss of residual kidney function (RKF) and increase vascular access complications. Multiple established databases were systematically searched; randomized and non-randomized studies were pooled separately. QoL outcomes were assessed using standardized mean difference (SMD), vascular access adverse events and mortality were assessed with relative risk ratios (RR). Four hundred seventy-six patients from six trials were eligible. Data from randomized controlled trials (RCTs) could only be synthesized for vascular access adverse events and mortality, which demonstrated no significant change in vascular access adverse events (RR 1.25, 95% CI 0.88 to 1.77) or mortality (RR 2.29, 95% CI 0.60 to 8.71). Pooled data from non-randomized trials demonstrated no significant difference in QoL (SF-36 Physical Component Summary SMD 0.61, 95% CI -0.10 to 1.31, SF-36 Mental Component Summary SMD -0.04, 95% CI -0.61 to 0.54). RKF was assessed in one report which demonstrated a potential reduction over 12 months with extended-hours hemodialysis. The majority of trials had high risk of bias. Extended-hours hemodialysis was not associated with improved QoL or mortality, or increased vascular access events. Adequately powered RCTs are needed to fully assess extended-hours hemodialysis.

Catheter Complications in Patients Undergoing Extracorporeal Photopheresis for Management of Graft-Versus-Host Disease

<h3>Introduction</h3> Complications associated with central vascular access (VA) in patients (pts) undergoing extracorporeal photopheresis (ECP) may limit therapy. VA options often include dual lumen vortex (DLV) implantable and tunneled trifusion/other (TF) catheters. There is limited data about VA associated complications such as infection, thrombosis, and equipment failure in those undergoing ECP. <h3>Objectives</h3> Our primary aim was to describe VA associated complications during ECP. <h3>Methods</h3> We retrospectively reviewed pts who received ECP at our institution from January 2011 to October 2019. We examined episodes of cellulitis, catheter associated bacterial infection (CLABSI), catheter removal/exchange (CRE), and discontinuation of ECP. <h3>Results</h3> Fifty-two pts had at least 4 ECP sessions using VA. 12 were treated for acute and 40 for chronic/overlap GvHD (cGvHD). Overall, median # ECP sessions (ES) was 35 (range 4-311), median # ECP months (EM) was 7 (range 0.5 to 86). Total number of VA events = 21. In cGvHD (n=40), Median ES was 50 (range 14-311). With DLV catheters (16/40 pts), total VA events = 8 (1 event every 133 ES). 5 events required CRE, and 3 pts resumed ECP after event. With TF catheters (24/40 pts), total VA events = 8 (1 event every 142 ES). 2 events required CRE, and 4 pts restarted ECP after event. In acute GVHD (n=12), median ES was 15 (range 4-83). 11/12 used a TF catheter. CLABSI was diagnosed in 5/12 pts, all of whom were already hospitalized for GvHD therapy. 3/5 required CRE. ECP was discontinued in all events due to progressive GvHD or infection. <h3>Conclusion</h3> During ECP for cGvHD treatment, DLV and TF catheters have similar number of complications (p=0.81) when adjusted for total ES and EM. VA events are a major cause of ECP discontinuation. In aGvHD, the high incidence of CLABSI is attributed to severe immunosuppression from therapy rather than specific catheter related events.

Mean Platelet Volume Predicts Vascular Access Events in Hemodialysis Patients.

Arteriovenous fistula (AVF) and arteriovenous graft (AVG) is the vascular access (VA) of 78% of hemodialysis patients (HD) in France. VA dysfunction corresponding to either stenosis requiring angioplasty or acute thrombosis is responsible for 30% of hospitalizations. Mean platelet volume (MPV) is a biological marker of cardiovascular events. We studied MPV in a cohort of HD patients as a predictive marker of VA dysfunction. We conducted a prospective monocentric cohort study that included patients with AVF or AVG on chronic HD (n = 153). The primary outcome was the incidence of VA dysfunction regarding MPV value. The median MPV was 10.8 fL (7.8–13.5), and four groups were designed according to MPV quartiles. Fifty-four patients experienced the first event of VA dysfunction. The incidence of VA dysfunction was higher in patients with the highest MPV: 59% (23 events), 34% (14 events), 27% (11 events), and 18% (6 events), respectively, for the fourth, third, second, and first quartiles (p = 0.001). Multivariate analysis confirmed an independent association between MPV and VA dysfunction—OR 1.52 (1.13–2.07), p < 0.001. VA dysfunction is predicted by MPV level. Patients with the highest MPV have the highest risk of VA events.

Validity of administrative database code algorithms to identify vascular access placement, surgical revisions, and secondary patency.

We assessed the validity of physician billing codes and hospital admission using International Classification of Diseases 10th revision codes to identify vascular access placement, secondary patency, and surgical revisions in administrative data. We included adults (≥18 years) with a vascular access placed between 1 April 2004 and 31 March 2013 at the University Health Network, Toronto. Our reference standard was a prospective vascular access database (VASPRO) that contains information on vascular access type and dates of placement, dates for failure, and any revisions. We used VASPRO to assess the validity of different administrative coding algorithms by calculating the sensitivity, specificity, and positive predictive values of vascular access events. The sensitivity (95% confidence interval) of the best performing algorithm to identify arteriovenous access placement was 86% (83%, 89%) and specificity was 92% (89%, 93%). The corresponding numbers to identify catheter insertion were 84% (82%, 86%) and 84% (80%, 87%), respectively. The sensitivity of the best performing coding algorithm to identify arteriovenous access surgical revisions was 81% (67%, 90%) and specificity was 89% (87%, 90%). The algorithm capturing arteriovenous access placement and catheter insertion had a positive predictive value greater than 90% and arteriovenous access surgical revisions had a positive predictive value of 20%. The duration of arteriovenous access secondary patency was on average 578 (553, 603) days in VASPRO and 555 (530, 580) days in administrative databases. Administrative data algorithms have fair to good operating characteristics to identify vascular access placement and arteriovenous access secondary patency. Low positive predictive values for surgical revisions algorithm suggest that administrative data should only be used to rule out the occurrence of an event.

A Trial of Extending Hemodialysis Hours and Quality of Life.

The relationship between increased hemodialysis hours and patient outcomes remains unclear. We randomized (1:1) 200 adult recipients of standard maintenance hemodialysis from in-center and home-based hemodialysis programs to extended weekly (≥24 hours) or standard (target 12-15 hours, maximum 18 hours) hemodialysis hours for 12 months. The primary outcome was change in quality of life from baseline assessed by the EuroQol 5 dimension instrument (3 level) (EQ-5D). Secondary outcomes included medication usage, clinical laboratory values, vascular access events, and change in left ventricular mass index. At 12 months, median weekly hemodialysis hours were 24.0 (interquartile range, 23.6-24.0) and 12.0 (interquartile range, 12.0-16.0) in the extended and standard groups, respectively. Change in EQ-5D score at study end did not differ between groups (mean difference, 0.04 [95% confidence interval, -0.03 to 0.11]; P=0.29). Extended hours were associated with lower phosphate and potassium levels and higher hemoglobin levels. Blood pressure (BP) did not differ between groups at study end. Extended hours were associated with fewer BP-lowering agents and phosphate-binding medications, but were not associated with erythropoietin dosing. In a substudy with 95 patients, we detected no difference between groups in left ventricular mass index (mean difference, -6.0 [95% confidence interval, -14.8 to 2.7] g/m2; P=0.18). Five deaths occurred in the extended group and two in the standard group (P=0.44); two participants in each group withdrew consent. Similar numbers of patients experienced vascular access events in the two groups. Thus, extending weekly hemodialysis hours did not alter overall EQ-5D quality of life score, but was associated with improvement in some laboratory parameters and reductions in medication burden. (Clinicaltrials.gov identifier: NCT00649298).

The use of vascular access audit and infections in home hemodialysis.

Vascular access-related infection is an important adverse event in home hemodialysis (HHD). We hypothesize that errors in self-cannulation or manipulation of dialysis vascular access are associated with increased incidence of access-related infection. We conducted a retrospective cohort study of all prevalent HHD patients at the University Health Network. All vascular access-related infections were recorded from 2006 to 2013. Errors in dialysis access were ascertained by nurse-administered vascular access checklist. Ninety-two patients had completed at least one vascular access audit. Median HHD vintage was 2.3 (0.9-5.0) years in patients with appropriate vascular access technique and 5.8 (1.5-9.4) years in patients with erroneous vascular access technique. The overall rate of infection between patients with and without appropriate vascular access technique was similar (0.27 and 0.28 infections per year, P = 0.166). Among patients who were identified with errors in dialysis access manipulation, patients with five or more errors were associated with higher rate of access-related infection (mean of 0.47 vs. 0.16 infection per patient-year, P < 0.001). The use of vascular access audit is a feasible strategy, which can identify errors in vascular access technique. Patients with a longer median HHD vintage are associated with higher risk of inappropriate vascular access technique. Patients with multiple errors in vascular access technique are associated with a higher risk of dialysis access-related infection. Prospective evaluation of the impact of vascular access audit on adverse vascular access events is warranted.

Association Between Vascular Access Dysfunction and Subsequent Major Adverse Cardiovascular Events in Patients on Hemodialysis: A Population-Based Nested Case-Control Study.

The association between dialysis vascular access dysfunction and the risk of developing major adverse cardiovascular events (MACE) in hemodialysis patients is unclear and has not yet been investigated. We analyzed data from the National Health Insurance Research Database of Taiwan to quantify this association. Adopting a case-control design nested within a cohort of patients who received hemodialysis from 2001 to 2010, we identified 9711 incident cases of MACE during the stage of stable maintenance dialysis and 19,422 randomly selected controls matched to cases on age, gender, and duration of dialysis. Events of vascular access dysfunction in the 6-month period before the date of MACE onset (ie, index date) for cases and before index dates for controls were evaluated retrospectively. The presence of vascular access dysfunction was associated with a 1.385-fold higher odds of developing MACE as estimated from the logistic regression analysis. This represents a significantly increased adjusted odds ratio (OR) at 1.268 (95% confidence interval [CI] = 1.186-1.355) after adjustment for comorbidities and calendar years of initiating dialysis. We also noted a significant exposure-response trend (P < 0.001) between the frequency of vascular access dysfunction and MACE, with the greatest risk (adjusted OR = 1.840, 95% CI = 1.549-2.186) noted in patients with ≥3 vascular access events. We concluded that dialysis vascular access dysfunction was significantly associated with an increased risk of MACE. Hence, vascular access failure can be an early sign for MACE in patients receiving maintenance hemodialysis. Active monitoring and treatment of cardiovascular risk factors and related diseases, not merely managing vascular access dysfunction, would be required to reduce the risk of MACE.

An international feasibility study of home haemodialysis in older patients.

Home haemodialysis (HHD) is undergoing a significant revival. There is a global demographic shift with a rising mean age of dialysis patients. We postulated that intensive HHD may also benefit the older dialysis population. However, there is a lack of literature on the feasibility of HHD in older patients with end-stage renal disease (ESRD). The purpose of this study was to ascertain the feasibility of delivering HHD to older patients. We conducted a multi-centre multinational retrospective cohort study of HHD patients ≥65 years of age at the time of HHD initiation; 79 patients were included. Baseline demographic data included age at start of dialysis, race and sex. Dialysis characteristics including total weekly treatment hours, need for assistance, training time, dialysis access, modality and dialysis vintage were captured, as well as cause of ESRD and medical co-morbidities. The primary outcome was time to technique failure or death. Rates of hospitalization, cardiovascular events, non-infectious vascular access events and infections were collected. Median age at start was 68 (interquartile range 66-71) years. An arteriovenous fistula was the predominant access, and most patients were receiving <16 h of total weekly dialysis treatment. Family or nurse assistance for dialysis was required in 54% of patients. There were 17 (22%) deaths and 20 (26%) technique failures. The cumulative time at risk was 188 years. Event-free survival at 1, 2 and 5 years was 85, 77 and 24%, respectively, and technique survival was 92, 83 and 56%, respectively. Advancing age (categorized into quartiles) was an unadjusted risk factor for death and technique failure. This analysis confirms feasibility of HHD in patients 65 years or older at the start of this modality and should foster further research on the potential benefits of (intensive) HHD in older ESRD patients.