Blood volume-monitored regulation of ultrafiltration to decrease the dry weight in fluid-overloaded hemodialysis patients: a randomized controlled trial.

BACKGROUND: Because chronic fluid volume overload is associated with higher mortality, we tested whether blood-volume monitored regulation of ultrafiltration and dialysate conductivity (UCR) and/or regulation of ultrafiltration and temperature (UTR) would facilitate dry weight reduction, in comparison to conventional dialysis (CONV). METHODS: We carried out a multicenter, 4-week, randomized controlled trial in hemodialysis patients ≥15% above normal extracellular fluid volume (ECV), per bioimpedance spectroscopy, who were randomized 1:1:1. Applying UCR (Nikkiso), UTR (Fresenius) and CONV, initial dry weight was reduced rapidly to target. Dry weight reduction was attenuated and eventually stopped at the occurrence of dialysis complications. The primary outcome was defined as intra- and postdialytic complications. Secondary outcomes were magnitudes of dry weight and blood pressure reduction. RESULTS: Of 244 patients assessed, N = 95 had volume overload ≥15% above normal ECV. Fifty patients received the allocated interventions (N = 16 UCR, N = 18 UTR, N = 16 CONV) and completed the trial. The rate of complications was significantly lower in UTR compared to CONV (21 ± 21% vs 34 ± 20%, p = 0.022), and also compared to UCR (vs 39 ± 27%, p = 0.028), but not statistically different between UCR and CONV (p = 0.93). Dry weight reduction was significantly higher in UTR compared to UCR (5.0 ± 3.4% vs 2.0 ± 2.7% body weight, p = 0.013), but not compared to CONV (vs 3.9 ± 2.1% body weight, p = 0.31). Systolic blood pressure reduction throughout the intervention phase was 17 ± 22 mmHg overall, but not significantly different between the three groups. Average maximum ultrafiltration rates were significantly higher in UTR than in UCR and CONV, at statistically similar dialysis times. Retrospective examination of randomly selected hemodialysis sessions in the UCR group identified technical mistakes in 36% of the dialysis sessions, despite considerable training efforts. CONCLUSIONS: Even in patients with volume overload, fluid removal was challenging. Despite the relative advantage of UTR, which must be interpreted with caution in view of the poor technical execution of UCR, this study renders clear that fluid removal must not be reinforced rapidly. Apprehension of this obstacle is imperative for future clinical and academic endeavors aimed at improving dialysis outcomes by correcting volume status. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT01416753 ), trial registration date: August 12, 2011.

Fluid overload in hemodialysis patients: a cross-sectional study to determine its association with cardiac biomarkers and nutritional status.

BACKGROUND: Chronic fluid overload is associated with higher mortality in dialysis patients; however, the link with cardiovascular morbidity has not formally been established and may be influenced by subclinical inflammation. We hypothesized that a relationship exists between fluid overload and [i] cardiovascular laboratory parameter as well as between fluid overload and [ii] inflammatory laboratory parameters. In addition, we aimed to confirm whether volume status correlates with nutritional status. METHODS: We recorded baseline characteristics of 244 hemodialysis patients at three hemodialysis facilities in Vienna (Austria) and determined associations with volume measurements using the body composition monitor (Fresenius/Germany). In one facility comprising 126 patients, we further analyzed cardiovascular, inflammatory and nutritional parameters. RESULTS: We detected predialysis fluid overload (FO) in 39% of all patients (n = 95) with FO defined as ≥15% of extracellular water (ECW). In this subgroup, the absolute FO was 4.4 +/-1.5 L or 22.9 ± 4.8% of ECW. A sub-analysis of patients from one center showed that FO was negatively associated with body mass index (r = -0.371; p = <0.001), while serum albumin was significantly lower in fluid overloaded patients (p = 0.001). FO was positively associated with D-Dimer (r = 0.316; p = 0.001), troponin T (r = 0.325; p < 0.001), and N-terminal pro-B-type natriuretic peptide (r = 0.436; p < 0.001), but not with investigated inflammatory parameters. CONCLUSIONS: Fluid overload in HD patients was found to be lower in patients with high body mass index, indicating that dry weight was inadequately prescribed and/or difficult to achieve in overweight patients. The association with parameters of cardiovascular compromise and/or damage suggests that fluid overload is a biomarker for cardiovascular risk. Future studies should determine if this applies to patients prior to end-stage renal disease.

Chronic Inflammation Might Protect Hemodialysis Patients From Severe COVID-19.

Hemodialysis patients (HD) are expected to have excess mortality in coronavirus disease 2019 (COVID-19). This was challenged by a recent study reporting HD patients to have comparable mortality and less ICU admissions when hospitalized with COVID-19. An altered immune system due to chronic inflammation might protect HD-patients from severe COVID-19. Therefore, we aimed to describe the peripheral blood immune phenotype in HD-patients and respective controls with COVID-19. Methods: Sixty-four patients (31 HD, 33 non-HD) with PCR-confirmed COVID-19 and 16 control patients (10 HD, 6 non-HD) were prospectively included. According to symptoms, COVID-19 patients were categorized as asymptomatic/mild, moderate or severe COVID-19 phenotypes. Cytokine profiling and immune phenotyping was performed. Results: Th1 and Th17 plasma cytokine levels were highly increased in HD patients without COVID-19 and were not significantly regulated during COVID-19. In non-HD COVID-19 patients these cytokines increased significantly with disease severity. While all patients with moderate or severe COVID-19 showed hallmarks of COVID-19 such as decreased CD3+, CD4+ and CD8+ and CD4+CD25hiFoxP3+ regulatory T cells, significantly increased CD38+CD8+ effector memory and CD38+CD8+ TEMRA T cells were detected in moderate/severe COVID-19 HD patients, which was not observed in non-HD patients with moderate or severe COVID-19. Furthermore, CD161+CD8+ T cells decreased significantly in non-HD COVID-19 patients dependent on disease severity, but not in HD patients. Dynamics of B cells and subtypes were comparable in HD and non-HD COVID-19 patients. Conclusions: HD patients might be protected from severe COVID-19 due to their chronic inflammatory state with increased CD38+CD8+ effector memory and TEMRA T cells as well as CD161+CD8+ T cells.

Impact of Timely Public Health Measures on Kidney Transplantation in Austria during the SARS-CoV-2 Outbreak-A Nationwide Analysis.

SARS-CoV-2 led to considerable morbidity/mortality worldwide and tremendously impacted on daily life. Strict lockdown measures were implemented early to contain the viral outbreak in Austria. Massive changes in organizational structures of healthcare facilities followed with unclear implications on the care of non-COVID-19-affected patients. We studied the nationwide impact of COVID-19 on kidney transplantation in Austria during the first six months of 2020. Concurrent with general lockdown measures, all kidney transplant activity was suspended from 13 March to 9 April. Nevertheless, between January and June, total transplant (p = 0.48) and procured donor organ numbers (p = 0.6) did not differ significantly from earlier years. Ten (0.18%) of 5512 prevalent Austrian kidney transplant recipients were diagnosed with SARS-CoV-2. The case fatality rate (one death; 10%) in renal transplant patients was less than in other countries but higher than in Austria's general population (2.4%). We conclude that early and strict general lockdown measures imposed by the government allowed an early, however cautious, re-opening of Austrian transplant programs and played a crucial role for the favorable outcomes of SARS-CoV-2 in Austrian kidney transplant patients. Even though it may be uncertain whether similar results may be obtainable in other countries, the findings may support early intervention strategies during similar episodes in the future.

Antithrombotic agents for primary and secondary prevention of cardiovascular events in patients with end-stage renal disease on chronic hemodialysis.

BACKGROUND AND AIMS: Cardiovascular disease (CVD) is common in patients with end-stage renal disease (ESRD) on hemodialysis (HD). However, antithrombotic therapy to prevent CVD increases the risk of bleeding. We aimed to investigate the prevalence of CVD and the practice patterns of antithrombotic agents in patients with ESRD on HD. METHODS: In a cross-sectional population based cohort of chronic HD patients (n = 626) from Vienna, Austria, the medical histories of patients and use of antithrombotic treatment were recorded, and the distribution of antithrombotic therapies for primary (n = 260, 41.5%) or secondary (n = 366, 58.5%) prevention of CVD was analyzed. RESULTS: Single antiplatelet therapy (SAPT) was used in 234 patients (37.4%), dual antiplatelet (DAPT) in 50 (8.0%), combination of anticoagulation and antiplatelet in 59 (9.4%), anticoagulation monotherapy in 78 (12.5%), and no antithrombotics in 205 patients (32.7%). The prevalence of CVD was 58.5%. In primary CVD prevention, 23.5% (n = 61) of patients were treated with SAPT. For secondary prevention, SAPT was used in 173 (47.3%), DAPT in 49 (13.4%), and dual antithrombotic therapies in 50 patients (13.7%), while 55 (15.0%) patients received no antithrombotics. Age (odds ratio [OR] per 1 year increase 0.96, 95%CI 0.94-0.99, p = 0.004) and hereditary nephropathy (OR 4.13, 95%CI 1.08-15.78, p = 0.038) were independently associated with the absence of antithrombotic therapy in secondary CVD prevention. CONCLUSION: The majority of patients did not receive antithrombotic therapy for primary prevention. Only 15% did not receive antithrombotic agents in the secondary prevention setting. The net-clinical benefit of antithrombotic therapy in ESRD needs to be determined.

Blood volume-monitored regulation of ultrafiltration in fluid-overloaded hemodialysis patients: study protocol for a randomized controlled trial.

BACKGROUND: Data generated with the body composition monitor (BCM, Fresenius) show, based on bioimpedance technology, that chronic fluid overload in hemodialysis patients is associated with poor survival. However, removing excess fluid by lowering dry weight can be accompanied by intradialytic and postdialytic complications. Here, we aim at testing the hypothesis that, in comparison to conventional hemodialysis, blood volume-monitored regulation of ultrafiltration and dialysate conductivity (UCR) and/or regulation of ultrafiltration and temperature (UTR) will decrease complications when ultrafiltration volumes are systematically increased in fluid-overloaded hemodialysis patients. METHODS/DESIGN: BCM measurements yield results on fluid overload (in liters), relative to extracellular water (ECW). In this prospective, multicenter, triple-arm, parallel-group, crossover, randomized, controlled clinical trial, we use BCM measurements, routinely introduced in our three maintenance hemodialysis centers shortly prior to the start of the study, to recruit sixty hemodialysis patients with fluid overload (defined as ≥15% ECW). Patients are randomized 1:1:1 into UCR, UTR and conventional hemodialysis groups. BCM-determined, 'final' dry weight is set to normohydration weight -7% of ECW postdialysis, and reached by reducing the previous dry weight, in steps of 0.1 kg per 10 kg body weight, during 12 hemodialysis sessions (one study phase). In case of intradialytic complications, dry weight reduction is decreased, according to a prespecified algorithm. A comparison of intra- and post-dialytic complications among study groups constitutes the primary endpoint. In addition, we will assess relative weight reduction, changes in residual renal function, quality of life measures, and predialysis levels of various laboratory parameters including C-reactive protein, troponin T, and N-terminal pro-B-type natriuretic peptide, before and after the first study phase (secondary outcome parameters). DISCUSSION: Patients are not requested to revert to their initial degree of fluid overload after each study phase. Therefore, the crossover design of the present study merely serves the purpose of secondary endpoint evaluation, for example to determine patient choice of treatment modality. Previous studies on blood volume monitoring have yielded inconsistent results. Since we include only patients with BCM-determined fluid overload, we expect a benefit for all study participants, due to strict fluid management, which decreases the mortality risk of hemodialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01416753.

Effective use of cinacalcet for the treatment of secondary hyperparathyroidism in Austrian dialysis patients--results of the Austrian cohort of the ECHO study.

BACKGROUND: Despite extensive use of standard therapy for secondary hyperparathyroidism (sHPT) in dialysis patients, still most patients do not achieve the recommended treatment targets. In a pan-European observational study (ECHO), the effectiveness of the calcimimetic cinacalcet for the treatment of sHPT was evaluated in real-world clinical practice. A sub-analysis of the entire Austrian study cohort is presented. METHODS: Adult dialysis patients who had initiated cinacalcet therapy were included. Data on biochemical parameters of bone and mineral metabolism (intact parathyroid hormone [iPTH], calcium [Ca] and phosphorus [P]) and concurrent medication were collected 6 months prior to the initiation of cinacalcet, at initiation (baseline) and after up to 12 months of active treatment. RESULTS: A total of 320 patients (mean age (±SD): 56 (±14) years) from 34 Austrian dialysis centres were enrolled. At baseline, patients presented with elevated serum iPTH (median 605 pg/ml) and hyperphosphataemia (median 2.1 mmol/l). After 12 months of cinacalcet treatment, serum iPTH (median percentage change -48%), calcium (-2%) and phosphorus (-6%) decreased. The greatest iPTH reduction (-66%) was found in patients with most severe sHPT (>800 pg/ml at baseline). The proportion of patients achieving the recommended NKF/K-DOQI(™) treatment targets increased from baseline to month 12 for iPTH (3-36%) and phosphorus (24 to 39%) and remained stable for calcium (51 to 50%), respectively. No patient had all 3 parameters simultaneously within NKF/K-DOQI(™) treatment targets at baseline, while 7% of patients achieved this treatment goal after 12 months. During the study the use of the phosphate binder sevelamer remained fairly stable, while the relative percentage use of calcium-based phosphate binders increased and the usage of aluminium-containing binders decreased; vitamin D analogue use remained stable. CONCLUSION: Additional use of cinacalcet improved biochemical parameters of bone and mineral metabolism and enabled more patients to achieve and maintain the KDOQI(™) treatment targets for serum iPTH, calcium and phosphorus.

Cell-free plasma DNA: a marker for apoptosis during hemodialysis.

BACKGROUND: We evaluated whether cell-free plasma DNA might be an appropriate marker for cell damage during hemodialysis (HD) and whether it correlated with annexin V expression and 7-amino-actinomycin D (7AAD) nuclear staining of blood leukocytes. METHODS: Circulating DNA, annexin V, and 7AAD were measured in HD patients before HD, 20 min after start of HD, and after HD had ended. Healthy volunteers provided control measurements. Necrosis and apoptosis were monitored by gel electrophoresis. RESULTS: Plasma DNA concentrations were not significantly different between controls and patients before HD. Circulating DNA increased significantly (P < 0.05) after 20 min of treatment with HD. Post-HD concentrations of DNA were significantly higher compared with pre-HD and controls (P < 0.005). Agarose gel electrophoresis showed ladders typical of apoptosis in post-HD samples. Two subpopulations of CD45+ leukocytes were defined by flow cytometry: annexin V+/7AAD+ population for apoptosis, and annexin V+/7AAD- for early apoptosis. Compared with healthy controls, mean fluorescence (MF) of 7AAD+ apoptotic cells in the annexin V+/7AAD+ subpopulation before HD was not significantly increased. HD increased MF of 7AAD+ cells in the annexin V+/7AAD+ subpopulation. In this subpopulation, MF of annexin V+ cells was significantly higher (P < 0.01). MF of annexin V+ cells in the annexin V+/7AAD+ subpopulation increased during HD. CONCLUSIONS: During HD, cell-free plasma DNA concentrations, annexin V expression, and 7AAD uptake in leukocytes increases. The increase in plasma DNA, appearing as ladders typical of apoptosis, and the 7AAD uptake in leukocytes demonstrate that the predominant portion of circulating DNA in HD patients originates from apoptotic leukocytes.