In patients with ESRD, the effects of online hemodiafiltration on all-cause mortality and cardiovascular events are unclear. In this prospective study, we randomly assigned 714 chronic hemodialysis patients to online postdilution hemodiafiltration (n=358) or to continue low-flux hemodialysis (n=356). The primary outcome measure was all-cause mortality. The main secondary endpoint was a composite of major cardiovascular events, including death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, therapeutic coronary intervention, therapeutic carotid intervention, vascular intervention, or amputation. After a mean 3.0 years of follow-up (range, 0.4-6.6 years), we did not detect a significant difference between treatment groups with regard to all-cause mortality (121 versus 127 deaths per 1000 person-years in the online hemodiafiltration and low-flux hemodialysis groups, respectively; hazard ratio, 0.95; 95% confidence interval, 0.75-1.20). The incidences of cardiovascular events were 127 and 116 per 1000 person-years, respectively (hazard ratio, 1.07; 95% confidence interval, 0.83-1.39). Receiving highvolume hemodiafiltration during the trial associated with lower all-cause mortality, a finding that persisted after adjusting for potential confounders and dialysis facility. In conclusion, this trial did not detect a beneficial effect of hemodiafiltration on all-cause mortality and cardiovascular events compared with low-flux hemodialysis. On-treatment analysis suggests the possibility of a survival benefit among patients who receive high-volume hemodiafiltration, although this subgroup finding requires confirmation.

Interdialytic hemodialysis catheter-locking solutions could contribute to a reduction of catheter-related complications, especially infections. However, they can cause side effects because of leakage from the tip of the catheter. Recently, trisodium citrate (TSC) has been advocated because of its antimicrobial properties and local anticoagulation. In a multicenter, doubleblind, randomized, controlled trial, TSC 30% was compared with unfractionated heparin 5000 U/ml for prevention of catheter-related infections, thrombosis, and bleeding complications. The study was stopped prematurely because of a difference in catheter-related bacteremia (CRB; P < 0.01). Of 363 eligible patients, 291 could be randomized. The study included 98 tunneled cuffed catheters and 193 untunneled. There were no significant differences in patient and catheter characteristics on inclusion. In the heparin group, 46% of catheters had to be removed because of any complication compared with 28% in the TSC group (P ‫؍‬ 0.005). CRB rates were 1.1 per 1000 catheter-days for TSC versus 4.1 in the heparin group (P < 0.001). For tunneled cuffed catheters, the risk reduction for CRB was 87% (P < 0.001) and for untunneled catheters was 64% (P ‫؍‬ 0.05). Fewer patients died from CRB in the TSC group (0 versus 5; P ‫؍‬ 0.028). There were no differences in catheter flow problems and thrombosis (P ‫؍‬ 0.75). No serious adverse events were encountered. Major bleeding episodes were significantly lower in the TSC group (P ‫؍‬ 0.010). TSC 30% improves overall patency rates and reduces catheter-related infections and major bleeding episodes for both tunneled and untunneled hemodialysis catheters. Flow problems are not reduced.

Renin, prorenin, and immunoreactive renin were present in vitreous and subretinal fluid of eyes from subjects with and without diabetic retinopathy. Renin substrate, albumin, transferrin, and immunoglobin G were also found in these ocular fluids. In many samples renin levels were close to the detection limit of the assay. The levels of renin substrate, albumin, transferrin, and immunoglobulin G varied widely among ocular fluid samples, but in each individual sample the levels were, relative to each other, similar to those in plasma. In contrast, the prorenin level in ocular fluid was up to 100 times higher than expected on the basis of the plasma protein content of ocular fluid. Moreover, there was little difference in prorenin concentrations between samples with low and high plasma protein contents. Prorenin, relative to albumin and other plasma proteins, was higher in vitreous fluid from eyes with proliferative diabetic retinopathy complicated by traction retinal detachment than in eyes of nondiabetic subjects with spontaneous retinal detachment. It appears that prorenin (and possibly renin) in ocular fluid is controlled by an active and specific process, possibly local synthesis within the eye. In view of the vascular actions of angiotensin II, an intraocular renin-angiotensin system may play a role in diabetic retinopathy.

These data demonstrate that standardized monitoring of either VP or Qa or the combination of both and subsequent corrective intervention can reduce thrombosis rate in grafts to below the recommended quality of care standard (that is, 0.5 per patient-year, NKF-DOQI). These surveillance strategies are equally effective in reducing thrombosis rates.

Although there were more interventions needed for access salvage in the patients with prosthetic graft implants, we may conclude that patients with poor forearm vessels do benefit from implantation of a prosthetic graft for vascular access.

Online hemodiafiltration may diminish inflammatory activity through amelioration of the uremic milieu. However, impurities in water quality might provoke inflammatory responses. We therefore compared the long-term effect of low-flux hemodialysis to hemodiafiltration on the systemic inflammatory activity in a randomized controlled trial. High-sensitivity C-reactive protein and interleukin-6 were measured for up to 3 years in 405 patients of the CONvective TRAnsport STudy, and albumin was measured at baseline and every 3 months in 714 patients during the entire follow-up. Differences in the rate of change over time of C-reactive protein, interleukin-6, and albumin were compared between the two treatment arms. C-reactive protein and interleukin-6 concentrations increased in patients treated with hemodialysis, and remained stable in patients treated with hemodiafiltration. There was a statistically significant difference in rate of change between the groups after adjustments for baseline variables (C-reactive protein difference 20%/year and interleukin-6 difference 16%/year). The difference was more pronounced in anuric patients. Serum albumin decreased significantly in both treatment arms, with no difference between the groups. Thus, long-term hemodiafiltration with ultrapure dialysate seems to reduce inflammatory activity over time compared to hemodialysis, but does not affect the rate of change in albumin.

SummaryBackground and objectives There is increasing awareness that residual renal function (RRF) has beneficial effects in hemodialysis (HD) patients. The aim of this study was to investigate the role of RRF, expressed as GFR, in phosphate and anemia management in chronic HD patients.Design, setting, participants, & measurements Baseline data of 552 consecutive patients from the Convective Transport Study (CONTRAST) were analyzed. Patients with a urinary output Ն100 ml/24 h (n ϭ 295) were categorized in tertiles on the basis of degree of GFR and compared with anuric patients (i.e., urinary output Ͻ100 ml/24 h, n ϭ 274). Relations between GFR and serum phosphate and erythropoiesis-stimulating agent (ESA) index (weekly ESA dose per kg body weight divided by hematocrit) were analyzed with multivariable regression models.Results Phosphate levels were between 3.5 and 5.5 mg/dl in 68% of patients in the upper tertile (GFR Ͼ 4.13 ml/min per 1.73 m 2 ), as compared with 46% in anuric patients despite lower prescription of phosphate-binding agents. Mean hemoglobin levels were 11.9 Ϯ 1.2 g/dl with no differences between the GFR categories. The ESA index was 31% lower in patients in the upper tertile as compared with anuric patients. After adjustments for patient characteristics, patients in the upper tertile had significantly lower serum phosphate levels and ESA index as compared with anuric patients. ConclusionsThis study suggests a strong relation between RRF and improved phosphate and anemia control in HD patients. Efforts to preserve RRF in HD patients could improve outcomes and should be encouraged.

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