Vascular Access for Hemodialysis and Value-Based Purchasing for ESRD

CMS ESRD quality incentive program has not improved patient dialysis vascular access

PURPOSE

Over 468,000 patients in the United States use hemodialysis to manage End Stage Renal Disease (ESRD). The purpose of this study was to determine whether the dialysis access Clinical Performance Measures (CPMs) of Centers for Medicare & Medicaid Services (CMS) ESRD Quality Incentive Program (QIP) have increased arteriovenous fistula (AVF) rates and decreased long-term tunneled hemodialysis catheter (TDC) rates among hemodialysis patients in United States.

METHODS

Retrospective observational study: evaluated reported AVF and long-term TDC rates of 4804 dialysis facilities which reported dialysis access data as part of the ESRD QIP from Payment Year (PY) 2014-2020. Facilities were also sorted by specific additional criteria to examine disparities in dialysis access.

RESULTS

Mean AVF rates of included facilities increased from 63.7% in PY 2014 to 67.2% in PY 2016 (p < 0.05), did not change in PY 2017 (p > 0.05), and declined significantly in PY 2018-2020 to 64.1% in PY 2020, near AVF rates at the inception of program. Long-term TDC rates decreased from 10.4% in PY 2014 to 9.88% in PY 2015 (p < 0.05), then increased in PY 2015-PY 2020 to rates higher than at the inception of program, at 11.8% in PY 2020 (p < 0.05). Facilities serving majority Black ZIP Code Tabulation Areas (ZCTAs) or ZCTAs with median income <$45,000 achieved significantly lower AVF rates (p < 0.05) with no significant difference in long-term TDC rates (p > 0.05). AVF rates correlated positively and long-term TDC rates correlated negatively with star rating of facilities (p < 0.05).

CONCLUSION

As one of the first financial QIPs in healthcare, the ESRD QIP has not achieved the stated goals of the CMS to increase AVF access rates above 68% and reduce long-term TDC clinical rates below 10%. Systemic disparities in race, geographic region, economic status, healthcare access, and education of providers and patients prevent successful attainment of goal metrics.

Influence of Tunneled Hemodialysis-Catheters on Inflammation and Mortality in Dialyzed Patients

Older age and comorbidities in hemodialysis patients determines the use of tunneled catheters as vascular access despite their reported clinical and mortality disadvantages. This prospective matched study analyzes the impact of permanent catheters on inflammation and mortality in hemodialysis patients; We studied 108 patients, 54 with AV-fistula (AVF) and 54 with indwelling hemodialysis catheters (HDC) matched by sex, age, diabetes and time under renal-replacement therapy comparing dialysis efficacy, inflammation and micro-inflammation parameters as well as mortality. Cox-regression analysis was applied to determine predictors of mortality, HDC patients presented higher C-reactive-protein (CRP) blood levels and percentage of pro-inflammatory lymphocytes CD14+/CD16+ with worse dialysis-efficacy parameters. Thirty-six-months mortality appeared higher in the HDC group although statistical significance was not reached. Age with a Hazard Ratio (HR) = 1.06, hypoalbuminemia (HR = 0.43), hypophosphatemia (HR = 0.75) and the increase in CD14+/CD16+ monocyte count (HR = 1.02) were predictors of mortality; elder patients dialyzing through HDC show increased inflammation parameters as compared with nAVF bearing patients, although they do not present a significant increase in mortality when matched by covariates. Increasing age and percentage of pro-inflammatory monocytes as well as decreased phosphate and serum-albumin were predictors of mortality and indicate the main conclusions or interpretations.

Reducing catheter-associated complications using 4% sodium citrate versus sodium heparin as a catheter lock solution

Objective

Use of a catheter lock solution plays a decisive role in vascular access. The effects of different concentrations of heparin and different types of catheter lock solutions are controversial. Therefore, this study aimed to compare the efficacy and safety of sodium citrate and sodium heparin catheter lock solutions.

Methods

A total of 120 patients were divided into four groups (30 patients per group) according to the use of catheter lock solution as follows: 6250 U/mL sodium heparin, 5000 U/mL sodium heparin, 2500 U/mL sodium heparin, and 4% sodium citrate. Coagulation function and the incidence of catheter occlusion, hemorrhage, and catheter-related infections were recorded.

Results

The different catheter lock solutions were significantly related to conduit blockage, hemorrhage, infection, and leakage levels. In the 4% sodium citrate group, the odds ratio was 0.688 for conduit blockage (95% confidence interval [CI], 0.206–2.297), 0.286 for hemorrhage (95% CI, 0.091–0.899), 0.266 for infection (95% CI, 0.073–0.964), and 0.416 for leakage (95% CI, 0.141–1.225) compared with the 6250 U/mL sodium heparin.

Conclusions

The solution 4% sodium citrate can effectively reduce the risk of catheter obstruction, bleeding, infection, and leakage better than sodium heparin in patients with long-term intravenous indwelling catheters.

The murine dialysis fistula model exhibits a senescence phenotype: pathobiological mechanisms and therapeutic potential

There is no therapy that promotes maturation and functionality of a dialysis arteriovenous fistula (AVF). The search for such therapies largely relies on evaluation of vascular responses and putative therapies in experimental AVFs. We studied an AVF in mice with chronic kidney disease (CKD). We demonstrate numerous stressors in the vein of the AVF-CKD group, including pathological shear, mitogenic, inflammatory, and hypoxia-reoxygenation stress. Because stress promotes premature senescence, we examined whether senescence is induced in the vein of the AVF-CKD model. We demonstrate a senescence phenotype in the AVF-CKD model, as indicated by increased expression of p16^Ink4a, p21^Cip1, and p53 and expected changes for certain senescence-associated microRNAs. RNA-sequencing analysis demonstrated differential expression of ~10,000 genes, including upregulation of proinflammatory and proliferative genes, in the vein of the AVF-CKD group. The vein in the AVF-CKD group exhibited telomere erosion and increased senescence-associated β-galactosidase activity and staining. Senescence was induced in the artery of the AVF-CKD group and in the vein of the AVF without CKD. Finally, given the rapidly rising clinical interest in senolytics, we provide proof of concept of senolytics as a therapeutic approach by demonstrating that senolytics decrease p16^Ink4a expression in the AVF-CKD model. This study introduces a novel concept underlying the basis for maturational and functional failure in human dialysis AVFs and identifies a new target for senolytic therapy.

Examining the Association between Hemodialysis Access Type and Mortality: The Role of Access Complications

BACKGROUND AND OBJECTIVES

People receiving hemodialysis to treat kidney failure need a vascular access (a fistula, a graft, or a central venous catheter) to connect to the blood purification machine. Higher rates of access complications are considered the mechanism responsible for the excess mortality observed among catheter or graft users versus fistula users. We tested this hypothesis using mediation analysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied incident patients who started hemodialysis therapy from North America, Europe, and Australasia (the Dialysis Outcomes and Practice Patterns Study; 1996-2011). We evaluated the association between access type and time to noninfectious (e.g., thrombosis) and infectious complications of the access (mediator model) and the relationship between access type and time-dependent access complications with 6-month mortality from the creation of the first permanent access (outcome model). In mediation analysis, we formally tested whether access complications explain the association between access type and mortality.

RESULTS

Of the 6119 adults that we studied (mean age =64 [SD=15] years old; 58% men; 47% patients with diabetes), 50% had a permanent catheter for vascular access, 37% had a fistula, and 13% had a graft. During the 6-month study follow-up, 2084 participants (34%) developed a noninfectious complication of the access, 542 (8.9%) developed an infectious complication, and 526 (8.6%) died. Access type predicted the occurrence of access complications; both access type and complications predicted mortality. The associations between access type and mortality were nearly identical in models excluding and including access complications (hazard ratio, 2.00; 95% confidence interval, 1.55 to 2.58 versus hazard ratio, 2.01; 95% confidence interval, 1.56 to 2.59 for catheter versus fistula, respectively). In mediation analysis, higher mortality with catheters or grafts versus fistulas was not the result of increased rates of access complications.

CONCLUSIONS

Hemodialysis access complications do not seem to explain the association between access type and mortality. Clinical trials are needed to clarify whether these associations are causal or reflect confounding by underlying disease severity.