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BACKGROUND - We practice the timely placement of an arteriovenous fistula (AVF) in patients facing chronic hemodialysis. We have anecdotally observed after AVF creation that there appears to be a slowing of the decline in kidney function as measured by the estimated glomerular filtration rate (eGFR). There are physiologically plausible explanations as to how an AVF might alter kidney function, but this clinical observation has been attributed to improved compliance and/or other practices. The present retrospective observational analysis was performed to assess the possibility that a successfully created AVF could be associated with the slowing of the eGFR trajectory.
METHODS - We identified 123 patients between 2005 and 2010 with at least two eGFR determinations for 2 years before and up to 2 years after AVF creation. Inclusion eligibility was that the fistula was maturing by the nephrologists' initial post-creation examination. Termination events were death, starting dialysis or transplantation. Each subject served as their own control for the pre- and post-AVF-creation eGFR measurements.
RESULTS - Subjects' median age was 68 years and 56% were diabetic. The rate of change of the eGFR for the 2 years prior to AVF creation was -5.9 mL/min/year (95% CI: -5.3, -6.5) and after AVF creation -0.5 mL/min/year (95% CI: -1.1, 0.1) (interaction (P < 0.001).
CONCLUSIONS - A functioning AVF may be associated with a slowing of the eGFR decline. Agreeing to timely AVF creation selects patients in an otherwise typical population and other confounders have not yet been eliminated. To do so a thorough prospective observational study is indicated.
© The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.
OBJECTIVE - During coagulation, factor IX (FIX) is activated by 2 distinct mechanisms mediated by the active proteases of either FVIIa or FXIa. Both coagulation factors may contribute to thrombosis; FXI, however, plays only a limited role in the arrest of bleeding. Therefore, therapeutic targeting of FXI may produce an antithrombotic effect with relatively low hemostatic risk.
APPROACH AND RESULTS - We have reported that reducing FXI levels with FXI antisense oligonucleotides produces antithrombotic activity in mice, and that administration of FXI antisense oligonucleotides to primates decreases circulating FXI levels and activity in a dose-dependent and time-dependent manner. Here, we evaluated the relationship between FXI plasma levels and thrombogenicity in an established baboon model of thrombosis and hemostasis. In previous studies with this model, antibody-induced inhibition of FXI produced potent antithrombotic effects. In the present article, antisense oligonucleotides-mediated reduction of FXI plasma levels by ≥ 50% resulted in a demonstrable and sustained antithrombotic effect without an increased risk of bleeding.
CONCLUSIONS - These results indicate that reducing FXI levels using antisense oligonucleotides is a promising alternative to direct FXI inhibition, and that targeting FXI may be potentially safer than conventional antithrombotic therapies that can markedly impair primary hemostasis.
BACKGROUND/AIMS - Pre-end-stage renal disease (ESRD) care is associated with improved outcomes among patients receiving dialysis. It is unknown what proportion of US micropolitan and rural dialysis patients receive pre-ESRD care and benefit from such care when compared to urban.
METHODS - A retrospective cohort study was performed using data from the US Renal Data System. Patients ≥18 years old who initiated dialysis in 2006 and 2007 were classified as rural, micropolitan or urban and the prevalence of pre-ESRD care (early nephrology care >6 months, permanent vascular access, -dietary education) was determined using the medical evidence report. The association of pre-ESRD care with dialysis mortality and transplantation was assessed using Cox regression with stratification for geographic residence.
RESULTS - Of 204,463 dialysis patients, 80% were urban, 10.2% were micropolitan and 9.8% were rural. Overall attainment of pre-ESRD care was poor. After adjustment, there were no significant geographic differences in attainment of early nephrology care or permanent dialysis access. Receiving care reduced all-cause mortality and increased the likelihood of transplantation to a similar degree regardless of geographic residence. Both micropolitan and rural patients received less dietary education (relative risk = 0.80, 95% CI = 0.76-0.84 and relative risk = 0.85, 95% CI = 0.80-0.89, respectively).
CONCLUSION - Among patients who receive dialysis, the prevalence of early nephrology care and permanent dialysis access is poor and does not vary by geographic residence. Micropolitan and rural patients receive less dietary education despite an observed mortality benefit, suggesting that barriers may exist to quality dietary care in more remote locations.
Copyright © 2013 S. Karger AG, Basel.
BACKGROUND - Hemodialysis (HD) access is considered a critical and actionable determinant of morbidity, with a growing literature suggesting that initial HD access type is an important marker of long-term outcomes. Accordingly, we examined HD access during the incident dialysis period, focusing on infection risk and successful fistula creation during the first dialysis year.
STUDY DESIGN - Longitudinal cohort.
SETTING & PARTICIPANTS - All US adults admitted to Fresenius Medical Care North America facilities within 15 days of first maintenance dialysis session between January 1 and December 31, 2007.
PREDICTOR - Vascular access type at HD therapy initiation.
OUTCOMES - Vascular access type at 90 days and at the end of the first year on HD therapy, bloodstream infection within the first year by access type, and catheter complication rate.
RESULTS - Of 25,003 incident dialysis patients studied, 19,622 (78.5%) initiated dialysis with a catheter; 4,151 (16.6%), with a fistula; and 1,230 (4.9%), with a graft. At 90 days, 14,105 (69.7%) had a catheter, 4,432 (21.9%) had a fistula, and 1,705 (8.4%) had a graft. Functioning fistulas and grafts at dialysis therapy initiation had first-year failure rates of 10% and 15%, respectively. Grafts were seldom replaced by fistulas (3%), whereas 7,064 (47.6%) of all patients who initiated with a catheter alone still had only a catheter at 1 year. Overall, 3,327 (13.3%) patients had at least one positive blood culture during follow-up, with the risk being similar between the fistula and graft groups, but approximately 3-fold higher in patients with a catheter (P<0.001 for either comparison). Nearly 1 in 3 catheters (32.5%) will require tissue plasminogen activator use by a median of 41 days, with 59% requiring more than one tissue plasminogen activator administration.
LIMITATIONS - Potential underestimation of bacteremia because follow-up blood culture results did not include samples sent to local laboratories.
CONCLUSIONS - In a large and representative population of incident US dialysis patients, catheter use remains very high during the first year of HD care and is associated with high mechanical complication and bloodstream infection rates.
Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Thrombosis is the leading cause of arteriovenous (AV) access failure for hemodialysis patients requiring frequent interventions. We describe a novel approach to the lyse-and-wait technique in thrombosed AV access using nurse-administered thrombolytics in a hospital-based hemodialysis unit. All patients at a single-center, large, urban, tertiary care hospital, who underwent in-center thrombolysis via alteplase instilled directly into a thrombosed AV access by inpatient hemodialysis unit staff between January 1, 2003 and December 31, 2007, were eligible. Included subjects were at least 18 years old and did not have known or suspected infection or trauma to the AV access site. Primary outcome measure was successful thrombolysis defined as hemodialysis performed immediately or after the interventional radiology (IR) procedure. Adverse events related to the procedure were collected. A total of 321 procedures, performed on 145 subjects (77 (53%) male, 68 (47%) female) remained for analysis. Successful instillation occurred in 317 of 321 procedures (98.8%). Successful thrombolysis occurred in 237 of 321 procedures (73.8%). Adverse events (8 major and 10 minor) occurred in 18 procedures, yielding a complication rate of 5.6%. In-center thrombolysis with alteplase administration by hemodialysis unit nursing staff under physician supervision is safe and effective with an adverse outcome rate similar to the literature. Thus, this modified lyse-and-wait protocol can be adopted with appropriate IR and surgical backup in place.
© 2012 Wiley Periodicals, Inc.
BACKGROUND AND OBJECTIVES - Referring hemodialysis patients for elective access angiography and percutaneous transluminal angioplasty (PTA) is commonly done to prevent access failure, yet the effectiveness of this procedure remains unclear. DESIGN, SETTING, PARTICIPANTS, & MEASURES: An observational matched cohort analysis among 40,132 Medicare beneficiaries receiving hemodialysis with a fistula or graft was performed. Cox regression was used to determine whether access intervention was associated with improved 1-year access survival.
RESULTS - Nonsurgical access intervention was found to be frequent at a rate of 20.9 procedures per 100 access years. In the 1-year period after intervention using angiography and PTA, the overall access failure rate was 53.7 per 100 access years in the intervention group and 49.6 in the nonintervention group (HR = 1.02; 95% CI, 0.96 to 1.08). Similar findings were also seen when the analysis was repeated in only fistulas (HR = 1.06; 95% CI, 0.98 to 1.15) and grafts (HR = 0.95; 95% CI, 0.86 to 1.05). In patients with a low intra-access flow rate (HR = 0.86; 95% CI, 0.75 to 0.99) or a new access (HR = 0.79; 95% CI, 0.71 to 0.89), angiography and PTA significantly increased access survival when compared with nonintervention (P for interaction was <0.0001). Angiography-PTA-related upper-extremity hematoma, vessel injury, or embolism-thrombosis occurred in 1.1% of all patients.
CONCLUSIONS - Access characteristics significantly modify the survival benefits of angiography and PTA intervention where the benefits of these interventions are most seen in newer accesses or accesses with insufficient flow.
BACKGROUND AND OBJECTIVES - Approximately one million Americans initiated chronic dialysis over the past decade; the first-year mortality rate reported by the U.S. Renal Data System was 19.6% in 2007. This estimate has historically excluded the first 90 days of chronic dialysis.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS - To characterize the mortality and hospitalization risks for patients starting chronic renal replacement therapy, we followed all patients initiating dialysis in 1733 facilities throughout the United States (n = 303,289). Mortality and hospitalizations within the first 90 days were compared with outcomes after this period, and the results were analyzed. Standard time-series analyses were used to depict the weekly risk estimates for each outcome.
RESULTS - Between 1997 and 2009, >300,000 patients initiated chronic dialysis and were followed for >35 million dialysis treatments; the highest risk for morbidity and mortality occurred in the first 2 weeks of treatment. The initial 2-week risk of death for a typical dialysis patient was 2.72-fold higher, and the risk of hospitalization was 1.95-fold higher when compared to a patient who survived the first year of chronic dialysis (week 53 after initiation). Similarly, over the first 90 days, the risk of mortality and hospitalization remained elevated. Thereafter, between days 91 and 365, these risks decreased considerably by more than half. Surviving these first weeks of dialysis was most associated with the type of vascular access. Initiating dialysis with a fistula was associated with a decreased early death risk by 61%, whereas peritoneal dialysis decreased the risk by 87%.
CONCLUSIONS - The first 2 weeks of chronic dialysis are associated with heightened mortality and hospitalization risks, which remain elevated over the ensuing 90 days.
Extended-release dipyridamole plus low-dose aspirin (ERDP/ASA) prolongs primary unassisted graft patency of newly created hemodialysis arteriovenous grafts, but the individual contributions of each component are unknown. Here, we analyzed whether use of aspirin at baseline associated with primary unassisted graft patency among participants in a randomized trial that compared ERDP/ASA and placebo in newly created grafts. We used Cox proportional hazards regression, adjusting for prespecified baseline comorbidities and covariates. Of all participants, 43% reported use of aspirin at baseline; of these, 82% remained on nonstudy aspirin (i.e., excluding ERDP/ASA) at 1 year. After 1 year of follow-up, the incidence of primary unassisted patency among participants using aspirin at baseline was 30% (95% CI: 24 to 35%) and among those not using aspirin was 23% (95% CI: 18 to 27%). Use of aspirin at baseline associated with a dose-dependent prolongation of primary unassisted graft patency that approached statistical significance (adjusted HR, 0.83; 95% CI: 0.68 to 1.01; P=0.06). Use of aspirin at baseline did not associate with prolongation of cumulative graft patency or participant survival. In conclusion, use of aspirin associates with a trend toward longer primary unassisted patency of newly placed hemodialysis grafts similar to that observed for ERDP/ASA.
Copyright © 2011 by the American Society of Nephrology
BACKGROUND AND OBJECTIVES - Conversion from central venous catheters to a graft or a fistula is associated with lower mortality risk in long-term hemodialysis (HD) patients; however, a similar association with hospitalization risk remains to be elucidated.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS - We conducted a prospective observational study all maintenance in-center HD patients who were treated in Fresenius Medical Care, North America legacy facilities; were alive on January 1, 2007; and had baseline laboratory data from December 2006. Access conversion (particularly from a catheter to a fistula or a graft) during the 4-month period from January 1 through April 30, 2007, was linked using Cox models to hospitalization risk during the succeeding 1-year follow-up period (until April 30, 2008).
RESULTS - The cohort (N = 79,545) on January 1, 2007 had 43% fistulas, 29% catheters, and 27% grafts. By April 30, 2007, 70,852 patients were still on HD, and among 19,792 catheters initially, only 10.3% (2045 patients) converted to either a graft or a fistula. With catheters as reference, patients who converted to grafts/fistulas had similar adjusted hazard ratios (0.69) as patients on fistulas (0.71), while patients with fistulas/grafts who converted to catheters did worse (1.22), all P < 0.0001.
CONCLUSIONS - Catheters remain associated with the greatest hospitalization risk. Conversion from a catheter to either graft or fistula had significantly lower hospitalization risk relative to keeping the catheter. Prospective studies are needed to determine whether programs that reduce catheters will decrease hospitalization risk in HD patients.
Mortality risk for dialysis patients is highest in the first year. We previously showed a 41% mortality benefit associated with a pilot case management program for incident hemodialysis patients (n = 918). The RightStart Program (RSP) provided prompt medical management and self-management education and was recently expanded to more facilities. We conducted a matched cohort analysis to validate the expanded program's continued effectiveness. Death risk was reduced for RS patients (n = 4308) versus matched controls (C; n = 4308) by 34% (hazard ratio = 0.66, P < 0.0001) at 120 d and 22% at 1 yr (hazard ratio = 0.78, P < 0.0001). RS patients had lower hospitalization during the first year (RS = 15.5 days per patient year versus C = 16.9, P < 0.01). At 120 d, more RS patients achieved hemoglobin 11 to 12 g/dl (RS = 22.4% versus C = 19.7%, P < 0.01), eKt/V > or = 1.2 (RS = 66% versus C = 53.5%, P < 0.01), albumin > or = 4.0 g/dl (RS = 26% versus C = 22%, P < 0.01), and phosphorus 3.5 to 5.5 mg/dl (RS = 52.4% versus C = 45.4%). At 120 d, RS patients had a greater reduction in catheter use (RS = 32% versus C = 25%, P < 0.01) and more vitamin D orders (RS = 60% versus C = 55%, P < 0.01). Expansion of RS to a larger incident patient population results in significant reduction of morbidity and mortality associated with improvement of intermediate outcomes.