Reduced Cardiovascular Mortality Associated with Early Vascular Access Placement in Elderly Patients with Chronic Kidney Disease

Racial Disparities in the Arteriovenous Fistula Care Continuum in Hemodialysis Patients

BACKGROUND AND OBJECTIVES

Arteriovenous fistulas are the optimal vascular access type for patients on hemodialysis. However, arteriovenous fistulas are used less frequently in Black than in White individuals. The arteriovenous fistula care continuum comprises a series of sequential steps. A better understanding is needed of where disparities exist along the continuum in order to mitigate racial differences in arteriovenous fistula use.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using Medicare claims data from the United States Renal Data System, longitudinal analyses of patients ≥67 years initiating hemodialysis with a central venous catheter between July 1, 2010 and June 30, 2012 were performed. Three patient cohorts were identified: patients initiating hemodialysis with a catheter (n=41,814), patients with arteriovenous fistula placement within 6 months of dialysis initiation (n=14,077), and patients whose arteriovenous fistulas were successfully used within 6 months of placement (n=7068). Three arteriovenous fistula processes of care outcomes were compared between Blacks and Whites: (1) arteriovenous fistula creation, (2) successful arteriovenous fistula use, and (3) primary arteriovenous fistula patency after successful use.

RESULTS

An arteriovenous fistula was placed within 6 months of dialysis initiation in 37% of patients initiating dialysis with a catheter. Among the patients with arteriovenous fistula placement, the arteriovenous fistula was successfully used for dialysis within 6 months in 48% of patients. Among patients with successful arteriovenous fistula use, 21% maintained primary arteriovenous fistula patency at 3 years. After adjusting for competing risks, Black patients on hemodialysis were 10% less likely to undergo arteriovenous fistula placement (adjusted subdistribution hazard ratio, 0.90; 95% confidence interval, 0.87 to 0.94); 12% less likely to have successful arteriovenous fistula use after placement (adjusted subdistribution hazard ratio, 0.88; 95% confidence interval, 0.83 to 0.93); and 22% less likely to maintain primary arteriovenous fistula patency after successful use (subdistribution hazard ratio, 0.78; 95% confidence interval, 0.74 to 0.84).

CONCLUSIONS

Lower arteriovenous fistula use among Blacks older than 67 years of age treated with hemodialysis was attributable to each step along the continuum of arteriovenous fistula processes of care.

Long-Term Outcomes of Arteriovenous Fistulas with Unassisted versus Assisted Maturation: A Retrospective National Hemodialysis Cohort Study

BACKGROUND

About half of arteriovenous fistulas (AVFs) require one or more interventions before successful dialysis use, a process called assisted maturation. Previous research suggested that AVF abandonment and interventions to maintain patency after maturation may be more frequent with assisted maturation versus unassisted maturation.

METHODS

Using the US Renal Data System, we retrospectively compared patients with assisted versus unassisted AVF maturation for postmaturation AVF outcomes, including functional primary patency loss (requiring intervention after achieving AVF maturation), AVF abandonment, and frequency of interventions.

RESULTS

We included 7301 patients ≥67 years who initiated hemodialysis from July 2010 to June 2012 with a catheter and no prior AVF; all had an AVF created within 6 months of starting hemodialysis and used for dialysis (matured) within 6 months of creation, with 2-year postmaturation follow-up. AVFs matured without prior intervention for 56% of the patients. Assisted AVF maturation with one, two, three, or four or more prematuration interventions occurred in 23%, 12%, 5%, and 4% of patients, respectively. Patients with prematuration interventions had significantly increased risk of functional primary patency loss compared with patients who had unassisted AVF maturation, and the risk increased with the number of interventions. Although the likelihood of AVF abandonment was not higher among patients with up to three prematuration interventions compared with patients with unassisted AVF maturation, it was significantly higher among those with four or more interventions.

CONCLUSIONS

For this cohort of patients undergoing assisted AVF maturation, we observed a positive association between the number of prematuration AVF interventions and the likelihood of functional primary patency loss and frequency of postmaturation interventions.

Hemodialysis vascular access in the elderly-getting it right

Choosing the optimal hemodialysis vascular access for the elderly patient is best achieved by a patient-centered coordinated multidisciplinary team approach that aligns the patient's end-stage kidney disease Life-Plan, i.e., the individual treatment approach (supportive care, time-limited or long-term kidney replacement therapy, or combination thereof) and selection of dialysis modality (peritoneal dialysis versus hemodialysis) with the most suitable dialysis access. Finding the right balance between the patient's preferences, the likelihood of access function and survival, and potential complications in the context of available resources and limited patient survival can be extremely challenging. The framework for choosing the most appropriate vascular access for the elderly presented in this review considers the individual end-stage kidney disease Life-Plan, the patient life expectancy, the likelihood of access function and survival, the timing of dialysis relative to access placement, prior access history, and patient preference. This complex decision-making process should be dynamic in order to accommodate patients' changing needs and life and health circumstances. Effective and timely communication between the patient, their caregivers, and treating team is key to delivering truly patient-centered care. Delivering this care also requires overcoming the limitations of the currently available evidence that is predominantly based on observational data with its inherent risks of bias. While challenging, future randomized controlled studies exploring the risks, benefits, costs, and timing of placement of available access types in the elderly are required to help us "get it right" for our patients.

Prehemodialysis arteriovenous access creation is associated with better cardiovascular outcomes in patients receiving hemodialysis: a population-based cohort study

Background

Cardiovascular (CV) disease contributes to nearly half of the mortalities in patients with end-stage renal disease. Patients who received prehemodialysis arteriovenous access (pre-HD AVA) creation had divergent CV outcomes.

Methods

We conducted a population-based cohort study by recruiting incident patients receiving HD from 2001 to 2012 from the Taiwan National Health Insurance Research Database. Patients’ characteristics, comorbidities, and medicines were analyzed. The primary outcome of interest was major adverse cardiovascular events (MACEs), defined as hospitalization due to acute myocardial infarction, stroke, or congestive heart failure (CHF) occurring within the first year of HD. Secondary outcomes included MACE-related mortality and all-cause mortality in the same follow-up period.

Results

The patients in the pre-HD AVA group were younger, had a lower burden of underlying diseases, were more likely to use erythropoiesis-stimulating agents but less likely to use renin–angiotensin–aldosterone system blockers. The patients with pre-HD AVA creation had a marginally lower rate of MACEs but a significant 35% lower rate of CHF hospitalization than those without creation (adjusted hazard ratio (HR) 0.65, 95% confidence interval (CI) [0.48–0.88]). In addition, the pre-HD AVA group exhibited an insignificantly lower rate of MACE-related mortality but a significantly 52% lower rate of all-cause mortality than the non-pre-HD AVA group (adjusted HR 0.48, 95% CI [0.39–0.59]). Sensitivity analyses obtained consistent results.

Conclusions

Pre-HD AVA creation is associated with a lower rate of CHF hospitalization and overall death in the first year of dialysis.

Gender Disparities in Vascular Access Surgical Outcomes in Elderly Hemodialysis Patients

BACKGROUND

Despite national vascular access guidelines promoting the use of arteriovenous fistulas (AVF) over arteriovenous grafts (AVGs) for dialysis, AVF use is substantially lower in females. We assessed clinically relevant AVF and AVG surgical outcomes in elderly male and female patients initiating hemodialysis with a central venous catheter (CVC).

METHODS

Using the United States Renal Data System standard analytic files linked with Medicare claims, we assessed incident hemodialysis patients in the United States, 9,458 elderly patients (≥67 years; 4,927 males and 4,531 females) initiating hemodialysis from July 2010 to June 2011 with a catheter and had an AVF or AVG placed within 6 months. We evaluated vascular access placement, successful use for dialysis, assisted use (requiring an intervention before successful use), abandonment after successful use, and rate of interventions after successful use.

RESULTS

Females were less likely than males to receive an AVF (adjusted likelihood 0.57, 95% CI 0.52-0.63). Among patients receiving an AVF, females had higher adjusted likelihoods of unsuccessful AVF use (hazard ratio [HR] 1.46, 95% CI 1.36-1.56), assisted AVF use (OR 1.34, 95% CI 1.17-1.54), and AVF abandonment (HR 1.28, 95% CI 1.10-1.50), but similar relative rate of AVF interventions after successful use (relative risk [RR] 1.01, 95% CI 0.94-1.08). Among patients receiving an AVG, females had a lower likelihood of unsuccessful AVG use (HR 0.83, 95% CI 0.73-0.94), similar rates of assisted AVG use (OR 1.05, 95% CI 0.78-1.40) and AVG abandonment, and greater relative rate of interventions after successful AVG use (RR 1.16, 95% CI 1.01-1.33).

CONCLUSIONS

While AVFs should be considered the preferred vascular access in most circumstances, clinical AVF surgical outcomes are uniformly worse in females. Clinicians should also consider AVGs as a viable alternative in elderly female patients initiating hemodialysis with a CVC to avoid extended CVC dependence.

Tradeoffs in Vascular Access Selection in Elderly Patients Initiating Hemodialysis With a Catheter

RATIONALE & OBJECTIVE

National vascular access guidelines recommend placement of arteriovenous fistulas (AVFs) over grafts (AVGs) in hemodialysis patients, but have not been comprehensively assessed in the elderly. We evaluated clinically relevant vascular access outcomes in elderly patients receiving an AVF or AVG after hemodialysis therapy initiation.

STUDY DESIGN

Retrospective cohort study using national administrative data.

SETTINGS & PARTCIPANTS

Claims data from the US Renal Data System of 9,458 US patients 67 years and older who initiated hemodialysis therapy from July 1, 2010, to June 30, 2011, with a catheter and received an AVF (n=7,433) or AVG (n=2,025) within the ensuing 6 months.

PREDICTOR

Arteriovenous access subtype, AVF or AVG.

OUTCOMES

Successful use of vascular access, interventions to make vascular access functional, duration of catheter dependence before successful use of vascular access, frequency of interventions, and abandonment after successful use of vascular access.

ANALYTICAL APPROACH

Multivariable logistic regression analysis was used to compare the need for intervention before successful use of AVFs and AVGs, and negative bionomial regression was used to calculate the frequency of intervention after successful use of vascular access.

RESULTS

Unsuccessful use of vascular access within 6 months of creation was higher for AVFs versus AVGs (51% vs 45%; adjusted HR, 1.86; 95% CI, 1.73-1.99). Interventions to make vascular access functional were greater in AVFs versus AVGs (42% vs 23%; OR, 2.66; 95% CI, 2.26-3.12). AVFs had a lower 1-year abandonment rate after successful use compared with AVGs (OR, 0.71; 95% CI, 0.62-0.83) and required one-fourth fewer interventions after successful use (relative risk, 0.75; 95% CI, 0.69-0.81). Patients receiving an AVF had substantially longer catheter dependence before successful use than those receiving an AVG (median time, 3 vs 1 month; P<0.001).

LIMITATIONS

Residual confounding due to vascular access choice, restriction to an elderly population, and 1-year follow-up period.

CONCLUSIONS

In elderly hemodialysis patients initiating hemodialysis therapy with a catheter, the optimal vascular access selection depends on tradeoffs between shorter catheter dependence and less frequent interventions to make the vascular access (AVG) functional versus longer access patency and fewer interventions after successful use of the vascular access (AVF).

Preoperative management of arteriovenous fistula (AVF) for hemodialysis

Native arteriovenous fistula (AVF) is the favorite access for hemodialysis (HD). The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) recommends its creation in most patients with renal failure. Unfortunately, intensive efforts to promote native AVF in patients with marginal vessels have increased the rate of primary fistula failure. A non-functioning fistula prompts the use of central venous catheter (CVC) that, unlike AVF, has been associated with an increased risk of morbidity and mortality among patients receiving HD. We believe that successful and timely AVF placement relies on the development of a multidisciplinary integrated preoperative program divided into five stages: (i) management of patients with advanced chronic kidney disease (CKD), (ii) management of preoperative risk factors for AVF failure, (iii) planning of native AVF, (iv) assessment of patient eligibility and (v) preoperative vascular mapping. Focusing specifically on native AVF, we review scientific evidence regarding preoperative management of this vascular access in order to favor construction of long-term functioning fistula minimizing development of severe complications.