Association Between Vascular Access Dysfunction and Subsequent Major Adverse Cardiovascular Events in Patients on Hemodialysis: A Population-Based Nested Case-Control Study

Association of Permanent Vascular Access Dysfunction with Subsequent Risk of Cardiovascular Disease: A Population-Based Cohort Study

A functional permanent vascular access (VA) is required to perform a successful hemodialysis procedure. Hemodialysis VA dysfunction is a major cause of morbidity and hospitalization in the hemodialysis population. Cardiovascular disease (CVD) is the leading cause of death in patients receiving chronic hemodialysis. Information about CVD associated with hemodialysis VA dysfunction is unclear. We analyzed the association between dialysis VA dysfunction and the risk of developing CVD in hemodialysis patients. This nationwide population-based cohort study was conducted using data from the National Health Insurance Research Database in Taiwan. One million subjects were sampled from 23 million beneficiaries and data was collected from 2000 to 2013. Patients with end-stage renal disease who had received permanent VA construction and hemodialysis and were aged at least 20 years old from 2000 to 2007 were included in the study population. The primary outcome was CVD, as defined by ICD-9-CM codes 410–414 and 430–437. A total of 197 individuals with permanent VA dysfunction were selected as the test group, and 100 individuals with non-permanent VA dysfunction were selected as the control group. Compared with the control group, the adjusted hazard ratio of CVD for the VA dysfunction group was 3.05 (95% CI: 1.14–8.20). A Kaplan–Meier analysis revealed that the cumulative incidence of CVD was higher in the permanent VA dysfunction group than in the comparison group. Permanent VA dysfunction is significantly associated with an increased risk of subsequent CVD.

Healthcare utilization and expenditure among individuals with end-stage kidney disease in Taiwan

BACKGROUND/PURPOSE

The prevalence of end-stage kidney disease (ESKD) in Taiwan has been increasing in recent decades. ESKD care and medical expenditures constitute an important part of the entire healthcare system.

METHODS

This study analyzed data collected from the National Health Insurance (NHI) Research Database from 2010 to 2018.

RESULTS

The annual medical cost increased by approximately 4% both in the entire Taiwanese population and in its ESKD population. The total medical expenditure in the ESKD population from 2010 to 2018 increased from 48.03 to 65.65 billion reimbursement points, with dialysis treatments costing higher than non-dialysis treatments. ESKD outpatient and inpatient costs accounted for 10.4%-11.1% and 4.8%-5.6% of the entire NHI expenditure, respectively. The leading cause of inpatient costs was circulatory diseases, accounting for 29.3% of the total ESKD inpatient costs in 2018. Furthermore, percutaneous coronary intervention had the highest cost followed by simple percutaneous transluminal angioplasty. In 2018, the hemodialysis population had the highest average monthly cost of 73 thousand points per person, while the kidney transplant population had the lowest average monthly cost of 39 thousand points per person.

CONCLUSIONS

Medical expenditure, including both inpatient and outpatient costs, of the ESKD population continued to grow from 2010 to 2018. The non-dialysis cost in the ESKD population was mainly for cardiovascular disease management and vascular access care, for which prevention will always be challenging.

Association of early failure of arteriovenous fistula with mortality in hemodialysis patients

Arteriovenous fistula (AVF) is prone to early dysfunction and relates to poor outcome. However, little is known about the role of early AVF dysfunction as an independent risk factor for death in hemodialysis patients. A retrospective cohort study was performed using data of patients who underwent initial AVF surgery at a single institution. Demographic, clinical, biochemistry and AVF parameters were extracted from the electronic records, and the association between these variables and mortality was analyzed by Cox proportional hazards model. A total of 501 patients on hemodialysis (63.4 ± 12.7 years, 57.3% male) were included, and the median observation period was 3.66 years. In multivariate analysis, early failure of AVF (hazard ratio (95% confidence interval): 1.54 (1.06–2.24); p = 0.023) was associated with overall mortality but not cardiovascular mortality. Other identified predictors of overall mortality included older age, peripheral artery disease (PAD), cardiomegaly, higher white blood cell (WBC) count and corrected calcium level, and lower total cholesterol level, while predictors of cardiovascular mortality included older age, coronary artery disease (CAD), PAD and lower hemoglobin level. In conclusion, patients with early AVF failure were associated with increased risk of overall mortality.

Blood temperature monitoring-guided vascular access intervention improved dialysis adequacy

OBJECTIVES

The aim of this study was to investigate whether blood temperature monitoring-guided vascular access intervention could improve dialysis adequacy.

METHODS

We retrospectively evaluated all patients who received outpatient-based prevalent hemodialysis patients (n = 84) in our artificial kidney room between January 2019 and October 2019. Through blood temperature monitoring, access blood flow was calculated every month and Kt/V was calculated every 3 months. The reference point was set at the time of vascular intervention in the patients (n = 27) who underwent intervention or at the middle of the study period in patients (n = 57) who did not undergo intervention. The mean blood temperature monitoring-estimated access flow and Kt/V before and after the reference point were calculated and compared.

RESULTS

Among 84 patients, 30 (35.7%) showed access flow rates of <500 mL/min, calculated by blood temperature monitoring during the study period. Twenty-seven patients (32.1%) underwent vascular intervention, of whom 24 (28.6%) showed access flow rates of <500 mL/min, 2 (2.4%) showed weak bruit or thrill incapable of needling, and 1 (1.2%) presented acute occlusion. Six patients (7.1%) whose access flow rates were <500 mL/min refused to undergo intervention. All angiographies in the patients whose access flow rates were <500 mL/min who underwent intervention showed a significant stenosis. The mean change in blood temperature monitoring-estimated access flow and Kt/V before and after vascular intervention was 483.3 ± 490.6 and 0.19 ± 0.21, respectively, which showed significant differences (all p < 0.05). A weak positive correlation between the mean change in blood temperature monitoring-estimated access flow and Kt/V was shown in all study patients by Pearson's correlation analysis (r = 0.234, p = 0.033).

CONCLUSION

Access flow estimation by blood temperature monitoring might identify candidates who require vascular intervention. Blood temperature monitoring-guided vascular intervention significantly improved access flow and dialysis adequacy.

Association of Dysfunction of Vascular Access for Hemodialysis With Major Adverse Cardiovascular Events - A Group-Based Trajectory Model Analysis

BACKGROUND

An unconventional risk factor, "dysfunction of hemodialysis vascular access", was demonstrated to be associated with subsequent major adverse cardiovascular events (MACE) in our previous study. However, applying this suggestion in a clinical scenario may be not intuitive. A group-based trajectory model was applied to further recognize those patients with the highest risks for MACE.

METHODS AND RESULTS

In a cohort of patients who received hemodialysis from 2001 to 2010, we identified 9,711 cases that developed MACE in the stage of stable maintenance dialysis, and 19,422 randomly selected controls matched to cases on age, gender and duration of dialysis. Events of vascular access dysfunction in the 6-month period before MACE for cases and index dates for controls were evaluated. By group-based trajectory modeling, patients according to their counts of vascular access dysfunction in each month over the 6-month period prior to MACE or index dates were categorized. There were 26,744 patients in group 1 (no dysfunction), 650 in group 2 (escalating dysfunction) and 1,739 in group 3 (persistent dysfunction). Logistic regression analysis indicated that patients in group 3 had the highest chance of subsequent MACE (odds ratio 2.47, in comparison with group 1) after controlling for all the available potential confounders.

CONCLUSIONS

Uninterrupted clusters of vascular access dysfunction are associated with a higher risk of subsequent MACE.

Association between initial dialytic modalities and the risks of mortality, infection death, and cardiovascular events: A nationwide population-based cohort study

To date, few studies have been conducted to pairwise compare the prognosis of peritoneal dialysis (PD), unplanned PD, and unplanned hemodialysis (HD). We analyzed longitudinal data from Taiwan’s National Health Insurance Research Database. We included 45,165 patients whose initial dialytic modality was PD or unplanned HD between January 1, 2001 and December 31, 2013. We divided the patients into three groups according to their initial dialytic modalities. The primary outcomes were all-cause mortality and death from infection during 1-year follow up. The risks of all-cause mortality and infection death were higher in the unplanned PD group than in the planned PD group (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.28–1.60; HR 1.54, 95% CI 1.32–1.80). Likewise, the risks of all-cause mortality and infection death were higher in the unplanned HD group (HR 1.64, 95% CI 1.48–1.82; HR 1.85, 95% CI 1.61–2.13). Furthermore, the risks of all-cause mortality and infection death were also higher in the unplanned HD group than in the unplanned PD group (HR 1.15, 95% CI 1.07–1.23; HR 1.20, 95% CI 1.09–1.32). In conclusion, our study demonstrates that patients whose initial modality was planned PD or unplanned PD may have better clinical outcomes than those whose initial modality was unplanned HD.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

High-Urgency Renal Transplantation for Patients With Vascular Access Failure: A Single-Center Experience

In the face of access failure for renal replacement therapy or severe complications despite or due to dialysis, high-urgency renal transplant (HU-RT) allocation is possible. Vascular access failure patients have multiple comorbidities and a higher risk of cardiovascular and thrombotic events. Thus, it is presumed that graft and patient survivals might be worse for these patients. The aim of this paper was to analyze the characteristics and outcomes of HU-RT patients due to access failure for renal replacement therapy when comparing them to a population of deceased-donor renal transplant (DDRT) patients. We analyzed data from our Renal Transplantation Unit from January 2006 to April 2017. In this period, 374 patients had a renal transplant. Of these, 11 patients received a high-urgency deceased-donor renal transplant (HU-DDRT). Compared with patients who had a DDRT, HU-DDRT patients were predominantly female (54.5% vs 43.5%, P = .007) and younger (41.6 ± 7.9 vs 49.4 ± 11.8, P = .031). HU-DDRT patients were not significantly more sensitized than DDRT (14.1 ± 27.4 vs 13.5 ± 24.1, P = .935), and had a comparable number of HLA mismatches (3.4 ± 1.4 vs 3.6 ± 1.2, P = .343). Despite the higher incidence in hypertensive (90.9 vs 73.5%, P = .196) and diabetic patients (27.3% vs 15.7%, P = .305) in the HU-DDRT group, this difference was not statistically significant. The percentage of retransplantation was similar in both groups (9.1% vs 7.2%, P = .808). Donor sex, age, and baseline serum creatinine were similar between the groups. There was an increased proportion of expanded criteria donors in HU-DDRT (54.5% vs 25.1%, P = .028). There were no differences in cold or warm ischemia time nor in serum creatinine at discharge or during the first 2 years of follow-up. In both groups, a similar proportion of patients experienced acute rejection episodes. Comparable to DDRT patients, HU-DDRT patients had a high proportion of graft survival at the 1-year follow-up (90.9% vs 93.1%, P = .777). At a 2-year follow-up, graft survival was lower in the HU-DDRT group (81.8% vs 91.5%, P = .267). Mean follow-up for both groups was comparable (78.5 ± 46.7 vs 68.4 ± 40.8 months, P = .424). Overall, graft loss occurred in approximately 36.4% of HU-DDRT patients and 20.9% of DDRT patients (P = .219). Both groups had an overall mortality rate of around 9%. The differences were not statistically significant due to the limited number of patients. More comorbidities and reportedly worse cardiovascular prognosis of access failure (AF) patients and use of expanded criteria donors did not negatively reflect in worse short-term outcomes in our cohort, which highlights the importance of HU-RT in prolonging the survival of AF patients.

Antiplatelet agents maintain arteriovenous fistula and graft function in patients receiving hemodialysis: A nationwide case-control study

Background

In this study, we evaluated the effects of various medications on the patency of vascular access (VA) for hemodialysis.

Methods

We analyzed data from the Longitudinal Health Insurance Database of Taiwan. We adopted a case–control study design within a cohort of patients who had received regular hemodialysis between 2002 and 2012; 34,354 patients with first VA failure were identified, and the duration from VA creation date to the first VA failure date was calculated. We then classified these patients into two groups, namely arteriovenous fistula (AVF, n = 25,933) and arteriovenous graft (AVG, n = 8,421). Each group was further divided into two subgroups, namely short-term (<1 year) and long-term (≥1 year) patency.

Results

The risk factors for early VA failure were age ≥65 years, diabetes mellitus, hyperlipidemia, cerebral vascular disease, congestive heart failure, peripheral artery disease, and sepsis. Male sex, hypertension, cancer, and peptic ulcer were associated with early AVF failure. Antiplatelet therapy increased the AVF and AVG patency times with adjusted odds ratios of 0.748 (95% confidence interval [CI]: 0.703–0.796, p < 0.0001) and 0.810 (95% CI: 0.728–0.901, p = 0.0001), respectively. A significant decrease in the VA failure risk was observed with an increase in the cumulative defined daily dose of antiplatelet agents.

Conclusion

This nationwide study demonstrated that some risk factors were associated with early VA failure and that the use of antiplatelet agents prevented the loss of VA patency in a dose–response manner. Thus, antiplatelet drugs should be routinely administered to high-risk patients receiving dialysis.

Factors affecting fistula failure in patients on chronic hemodialysis: a population-based case-control study

Background

With advancement of hemodialysis (HD) technique, late fistula failure (LFF) remains a problem significantly affecting life quality of patients. We attempt to identify factors affecting LFF in patients on chronic HD in Taiwan from the National Health Insurance Research Database.

Methods

This case–control study enrolled patients over 18 years old and who received regular HD for more than 3 months. LFF was defined as the first fistula failure episode beyond 3 months of chronic HD. We analyzed characteristics, comorbidities and medicine and investigated the association factors of LFF by logistic regression model. A trend test was conducted for risk in different provider levels. Sensitivity tests were conducted to test consistency.

Results

Of 1558 patients recruited, 772 (49.6%) were identified as LFF cases and 786 were identified as controls. The data showed that patients with diabetes mellitus (DM) had 42% increased rate of LFF. Patients receiving more than 10 HD sessions per month had a 90% increased rate of LFF; patients receiving chronic HD in private clinics had a 49% reduction rate of LFF. There were no significant differences in age, dialysis frequency, and comorbidities among different provider levels. There was a significant trend of risk reduction of the event from medical centers, regional hospitals, district hospitals, to private clinics. The sensitivity tests revealed similar results.

Conclusions

The factors associated with LFF include DM and receiving more HD sessions; on the contrary, receiving HD in private clinics is associated with less risk of LFF.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1010-6) contains supplementary material, which is available to authorized users.

The Use of Aspirin to Reduce the Risk of Thrombotic Events in Patients With End-Stage Renal Disease: Protocol for a Randomized Controlled Trial

Background

End-stage renal disease (ESRD) is the last stage of chronic kidney disease, mainly caused by type 2 diabetes mellitus and characterized by an increased mortality risk related to cardiovascular disease. Low-dose aspirin (acetylsalicylic acid or ASA) seems to effectively prevent cardiovascular events in patients with ESRD. However, the number of interventional studies in this population remains limited and the mechanisms of aspirin-related bleeding remain poorly understood. Aspirin’s efficacy and safety may be modified by the presence of type 2 diabetes mellitus or platelet hyperreactivity.

Objective

The overall objective of this protocol is to (1) evaluate aspirin’s safety and efficacy in reducing the risk of thrombotic events in patients with ESRD on hemodialysis and (2) examine whether aspirin’s efficacy is modified by the presence of type 2 diabetes mellitus or platelet hyperreactivity. Specifically, the primary objective is to compare the 12-month rate of any thrombotic event (cardiac death, nonfatal myocardial infarction, nonfatal stroke, arteriovenous fistula thrombosis) and Thrombolysis in Myocardial Infarction (TIMI) major bleeding in patients treated with aspirin compared to those on placebo. Secondary objectives are to test for effect modification of treatment by the presence of type 2 diabetes mellitus or platelet hyperreactivity and compare the rate of TIMI minor bleeding between treatment groups.

Methods

We developed a protocol for a phase 2 randomized, single-center, placebo-controlled, triple-blind, superiority clinical trial to assess the prophylactic efficacy and safety of aspirin in patients with ESRD and on hemodialysis. It follows the ethical principles of the Declaration of Helsinki of the World Medical Association. A total of 342 participants would be enrolled over 12 months at a large dialysis center. Patients will be randomized in a 1:1 ratio and stratified by presence of type 2 diabetes mellitus and platelet hyperreactivity to receive either oral aspirin (100 mg/d) or placebo for a treatment period of 12 months. An intention-to-treat statistical analysis will be performed.

Results

The randomized clinical trial will be performed after approval by the ethical committee of the participating center and registration at ClinicalTrials.gov.

Conclusions

We provide a protocol for a randomized controlled trial to evaluate the safety and efficacy of treatment with aspirin to reduce the risk of thrombotic events. In addition, such a study would further our understanding of the mechanism of aspirin-related bleeding and help identify subgroups of best-responders and patients with a higher risk of adverse events.

Registered Report Identifier

RR1-10.2196/10516

Association of early loss of primary functional patency of arteriovenous access with mortality in incident hemodialysis patients: A nationwide population-based observational study

The long-term survival and life quality of hemodialysis (HD) patients depend on adequacy of dialysis via a well-functioning vascular access. Loss of primary functional patency (PFP) of an arteriovenous access (AVA) eventually happens in HD patients. The association between time to loss of PFP of AVAs and mortality in HD patients remains unclear. The retrospective nationwide population-based cohort study compared the hazards of mortality with time to loss of PFP. We enrolled 1618 adult incident HD patients who received HD via AVAs for at least 90 days between January 1, 2001 and December 31, 2013. They were divided into early (≤1 year) and late (>1 year) loss of PFP according to intervention-free intervals (time from first successful cannulation to percutaneous transluminal angioplasty [PTA]). Patients with early loss of PFP were older; had more clinic visits annually and higher Charlson comorbidity index scores; were associated with higher proportions of diabetes mellitus, coronary artery disease, heart failure, stroke, chronic obstructive pulmonary disease, cancer, and use of arteriovenous graft, diuretic, antidiabetic drugs, and aspirin (all P < .05). Kaplan-Meier analysis revealed the cumulative incidence of mortality was significantly higher in patients with early loss of PFP (log-rank test; P < .01). After adjustment, early loss of PFP was independently associated with a higher risk of mortality (adjusted hazard ratio, 1.21; 95% confidence interval, 1.01-1.45; P = .045). Regarding the impact of time to PTA on mortality, patients with intervention-free intervals of ≤3, 3 to 6, and 6 to 12 months had similar trends of lower survival. Early loss of PFP is an independent risk factor for mortality in chronic HD patients. A comprehensive strategy for maintaining PFP and reducing dysfunctional AVAs may be required.

Association of vascular access flow with short-term and long-term mortality in chronic haemodialysis patients: a retrospective cohort study

OBJECTIVES

To investigate the impact of vascular access flow (Qa) on vascular and all-cause mortality in chronic haemodialysis (HD) patients.

DESIGN

Observational cohort study.

SETTING

Single centre.

PARTICIPANTS

Adult chronic HD patients at the HD unit of Shin Kong Wu Ho-Su Memorial Hospital between 1 January 2003 and 31 December 2003 were recruited. Patients were excluded if they had arteriovenous fistula or arteriovenous graft failure within 3 months before the date of Qa measurement, were aged <18 years and had Qa levels of ≥2000mL/min. A total of 378 adult chronic HD patients were eventually enrolled for the study.

INTERVENTIONS

The selected patients were evaluated with Qa and cardiac index (CI). They were divided into four groups according to three Qa cut-off points (500, 1000 and 1500 mL/min).

PRIMARY AND SECONDARY OUTCOME MEASURES

Short-term and long-term vascular (cardiovascular or cerebrovascular) and all-cause mortality.

RESULTS

Qa was positively correlated with CI (r=0.48, p<0.001). A Qa level of <1000 mL/min was independently associated with 1-year all-cause mortality (adjusted OR, 6.04; 95% CI 1.64 to 22.16; p=0.007). Kaplan-Meier analysis revealed that the cumulative incidence rates of all-cause and vascular mortality were significantly higher in the patients with a Qa level of <1000 mL/min (log-rank test; all p<0.01). Furthermore, a Qa level of <1000 mL/min was independently associated with long-term all-cause mortality (adjusted HR, 1.62; 95% CI 1.11 to 2.37; p=0.013); however, the risk of vascular mortality did not significantly increase after adjustment for confounders.

CONCLUSIONS

Qa is moderately correlated with cardiac function, and a Qa level of <1000 mL/min is an independent risk factor for both short-term and long-term all-cause mortality in chronic HD patients.

SiO2-induced release of sVEGFRs from pulmonary macrophages

BACKGROUND

The inhalation of silicon dioxide (SiO₂) particles causes silicosis, a stubborn pulmonary disease that is characterized by alveolar inflammation during the early stage. Soluble cytokine receptors (SCRs) play important roles in regulating inflammation by either attenuating or promoting cytokine signaling. However, the role of SCRs in silicosis remains unknown.

METHODS AND RESULTS

Luminex assays revealed increased soluble vascular endothelial growth factor receptor (sVEGFR) family levels in the plasma of silicosis patients. In an enzyme-linked immunosorbent assay (ELISA), cells from the differentiated human monocytic cell line U937 released sVEGFR family proteins after exposure to SiO₂ (50μg/cm²). Further Western blot experiments revealed that VEGFR expression was also elevated in U937 cells. In contrast, levels of sVEGFR family members did not change in the supernatants of human umbilical vein endothelial cells (HUVECs) after exposure to SiO₂ (50μg/cm²). Interestingly, VEGFR expression in HUVECs decreased after SiO₂ treatment. In a scratch assay, HUVECs exhibited cell migration ability, indicating the acquisition of mesenchymal properties.

CONCLUSION

Our findings highlight the important role of sVEGFRs in both inflammation and fibrosis induced by SiO₂, suggesting a possible mechanism for the fibrogenic effects observed in pulmonary diseases associated with fibrosis.

Panax notoginseng saponins ameliorate impaired arterial vasodilation in SHRSP.Z-Lepr(fa) /lzmDmcr rats with metabolic syndrome

Panax notoginseng saponins (PNS) are major components of Panax notoginseng, a herb with established clinical efficacy against vascular diseases. SHRSP.Z-Lepr(fa) /IzmDmcr (SHRSP.ZF) rats, a new animal model for metabolic syndrome, display an impaired vasorelaxation response in aortas and mesenteric arteries that is mediated by nitric oxide (NO). This study investigated whether PNS and its components can ameliorate this vascular dysfunction in SHRSP.ZF rats. In an in vitro study, in the presence or absence of PNS and its components, vasodilation in response to nitroprusside was determined from myographs under isometric tension conditions in aortas and mesenteric arteries from male SHRSP.ZF rats at 18-20 weeks of age. In an in vivo study, PNS (30 mg/kg per day) was orally administered to SHRSP.ZF rats from 8 to 20 weeks of age. In vitro treatment with PNS and Ginsenoside Rb1 increased nitroprusside-induced relaxation of aortas and mesenteric arteries in SHRSP.ZF rats. The PNS-induced increase was not affected by a nitric oxide (NO) synthase inhibitor or endothelium denudation. Relaxation in response to a cell-permeable cGMP analogue was increased by PNS, but cGMP accumulation by nitroprusside was not altered. In vivo treatment with PNS in SHRSP.ZF rats lowered blood pressure and increased relaxation and the expression of soluble guanylyl cyclase protein in arteries, without affecting metabolic abnormalities. These results indicate that PNS causes an increase in vasodilation in response to NO and a decrease in blood pressure, resulting in protection against vascular dysfunction in SHRSP.ZF rats. PNS might be beneficial in alleviating impaired vasodilation in metabolic syndrome.