Hypertriglyceridemia as a Cause of Continuous Renal Replacement Therapy Circuit Clotting: A Case Series.

INTRODUCTION: Hypertriglyceridemia is a rarely reported cause of early continuous renal replacement therapy (CRRT) circuit clotting. METHODS: We have identified and will present 11 published cases in the literature where hypertriglyceridemia has led to CRRT circuit clotting or dysfunction. RESULTS: The majority of cases (8/11) are related to propofol use leading to hypertriglyceridemia. The other cases (3/11) are due to total parenteral nutrition administration. CONCLUSION: Due to the propensity of propofol use for critically ill patients in intensive care units, and the rather common occurrence of CRRT circuit clotting, hypertriglyceridemia may be underappreciated and undiagnosed. The exact pathophysiology behind hypertriglyceridemia-induced CRRT clotting has not been fully elucidated, although there are some hypotheses which include fibrin and fat droplet deposition (identified after electron microscopic examination of the hemofilter), increased blood viscosity, and development of a procoagulant state. Premature clotting poses a multitude of problems including inadequate treatment time, increased costs, increasing nursing workload, and patient blood loss. With earlier identification, discontinuation of the inciting agent, and possible therapeutic management, we could expect improvement in CRRT hemofilter patency and decreased costs.

Study protocol for Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) : A multi-center, multinational validation study to assess the accuracy and feasibility of measuring vascular access function in clinical practice.

BACKGROUND: A functioning vascular access (VA) is crucial to providing adequate hemodialysis (HD) and considered a critically important outcome by patients and healthcare professionals. A validated, patient-important outcome measure for VA function that can be easily measured in research and practice to harvest reliable and relevant evidence for informing patient-centered HD care is lacking. Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) aims to assess the accuracy and feasibility of measuring a core outcome for VA function established by the international Standardized Outcomes in Nephrology (SONG) initiative. METHODS: VALID is a prospective, multi-center, multinational validation study that will assess the accuracy and feasibility of measuring VA function, defined as the need for interventions to enable and maintain the use of a VA for HD. The primary objective is to determine whether VA function can be measured accurately by clinical staff as part of routine clinical practice (Assessor 1) compared to the reference standard of documented VA procedures collected by a VA expert (Assessor 2) during a 6-month follow-up period. Secondary outcomes include feasibility and acceptability of measuring VA function and the time to, rate of, and type of VA interventions. An estimated 612 participants will be recruited from approximately 10 dialysis units of different size, type (home-, in-center and satellite), governance (private versus public), and location (rural versus urban) across Australia, Canada, Europe, and Malaysia. Validity will be measured by the sensitivity and specificity of the data acquisition process. The sensitivity corresponds to the proportion of correctly identified interventions by Assessor 1, among the interventions identified by Assessor 2 (reference standard). The feasibility of measuring VA function will be assessed by the average data collection time, data completeness, feasibility questionnaires and semi-structured interviews on key feasibility aspects with the assessors. DISCUSSION: Accuracy, acceptability, and feasibility of measuring VA function as part of routine clinical practice are required to facilitate global implementation of this core outcome across all HD trials. Global use of a standardized, patient-centered outcome measure for VA function in HD research will enhance the consistency and relevance of trial evidence to guide patient-centered care. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03969225. Registered on 31st May 2019.

The association between the public reporting of individual operator outcomes with patient profiles, procedural management, and mortality after percutaneous coronary intervention: an observational study from the Pan-London PCI (BCIS) Registry using an interrupted time series analysis.

AIMS: The public reporting of healthcare outcomes has a number of potential benefits; however, unintended consequences may limit its effectiveness as a quality improvement process. We aimed to assess whether the introduction of individual operator specific outcome reporting after percutaneous coronary intervention (PCI) in the UK was associated with a change in patient risk factor profiles, procedural management, or 30-day mortality outcomes in a large cohort of consecutive patients. METHODS AND RESULTS: This was an observational cohort study of 123 780 consecutive PCI procedures from the Pan-London (UK) PCI registry, from January 2005 to December 2015. Outcomes were compared pre- (2005-11) and post- (2011-15) public reporting including the use of an interrupted time series analysis. Patients treated after public reporting was introduced were older and had more complex medical problems. Despite this, reported in-hospital major adverse cardiovascular and cerebrovascular events rates were significantly lower after the introduction of public reporting (2.3 vs. 2.7%, P < 0.0001). Interrupted time series analysis demonstrated evidence of a reduction in 30-day mortality rates after the introduction of public reporting, which was over and above the existing trend in mortality before the introduction of public outcome reporting (35% decrease relative risk 0.64, 95% confidence interval 0.55-0.77; P < 0.0001). CONCLUSION: The introduction of public reporting has been associated with an improvement in outcomes after PCI in this data set, without evidence of risk-averse behaviour. However, the lower reported complication rates might suggest a change in operator behaviour and decision-making confirming the need for continued surveillance of the impact of public reporting on outcomes and operator behaviour.

Fistula first is not always the best strategy for the elderly.

Whether placing a fistula first is the superior predialysis approach among octogenarians is unknown. We analyzed data from a cohort of 115,425 incident hemodialysis patients ≥67 years old derived from the US Renal Data System with linked Medicare claims, which allowed us to identify the first predialysis vascular access placed rather than the first access used. We used proportional hazard models to evaluate all-cause mortality outcomes based on first vascular access placed, considering the fistula group as the reference. In the study population, 21,436 patients had fistulas as the first predialysis access placed, 3472 had grafts, and 90,517 had catheters. Those patients with a catheter as the first predialysis access placed had significantly inferior survival compared with those patients with a fistula (HR=1.77; 95% CI=1.73 to 1.81; P<0.001). However, we did not detect a significant mortality difference between those patients with a graft as the first access placed and those patients with a fistula (HR=1.05; 95% CI=1.00 to 1.11; P=0.06). Analyzing mortality stratified by age groups, grafts as the first predialysis access placed had inferior mortality outcomes compared with fistulas for the 67 to ≤79-years age group (HR=1.10; 95% CI=1.02 to 1.17; P=0.007), but differences between these groups were not statistically significant for the 80 to ≤89- and the >90-years age groups. In conclusion, fistula first does not seem to be clearly superior to graft placement first in the elderly, because each strategy associates with similar mortality outcomes in octogenarians and nonagenarians.

γCyclodextrin-assisted Aqueous Extract of Cinnamon for Cancer and Stress Management.

AIM: Our goal was to investigate the use of Cyclodextrin in creating an aqueous extract of Cinnamon with a high content of its bioactive ingredients, validated by cell-based assays. BACKGROUND: Due to their safety and cost-effectiveness, natural compounds have garnered attention for cancer therapy, which often faces challenges related to drug toxicity and resistance. Cinnamon (Cinnamomum verum; also known as Ceylon Cinnamon) is a commonly used spice with a history in folk medicine for treating various ailments. However, its active ingredients suffer from poor solubility, stability, and bioavailability, which limits its use and benefits. OBJECTIVE: We prepared γCyclodextrin (γCD)-assisted aqueous extract of Cinnamon (CD-CIN) and compared its activity with the DMSO extract (DM-CIN). METHODS: The cells were exposed to CD-CIN and DM-CIN extracts under normal and stressed (oxidative, metal, and hypoxic) conditions and then analyzed for stress and cancerous phenotypes using various molecular assays. RESULTS: We found that CD-CIN possesses considerable anticancer activity that involves the activation of tumor suppressor proteins and DNA damage response. Low, non-toxic concentrations of DM-CIN and CD-CIN caused comparable inhibition of migration and invasion capability of cells, supported by molecular marker analyses. Furthermore, protection against oxidative, metal, and hypoxia stress, as well as induction of differentiation, was recorded in both DM-CIN and CD-CIN treated cells, as compared to the control. CONCLUSION: We report CD-CIN as a new economic and easy Cinnamon-derived resource that possesses considerable anticancer and antistress activities and hence warrants further chemical, in vitro, and in vivo studies.

The role of initial hemodialysis vascular access in the outcome of subsequent kidney transplantation.

The role of initial hemodialysis vascular access in the subsequent kidney transplant outcome is unclear. Study population was derived from the United States Renal Data System and included adult patients with end-stage renal disease who started HD 1/1/2005-9/1/2009 and subsequently received at least one kidney transplant. Primary outcome variables were death-censored graft loss and all-cause recipient mortality. Among the study population (n = 17 157), 12 428 (72.4%) patients were initiated on HD with a catheter, 4090 (23.8%) patients with an arterio-venous fistula (AVF), and 639 (13.7%) patients with an arterio-venous graft (AVG). The rate of death-censored kidney allograft loss in AVF and AVG groups was not significantly different from the catheter group (HR, 0.82; p = 0.07 and HR, 0.68; p = 0.13, respectively). All-cause mortality of patients initiated on HD with AVG (HR, 0.761; p = 0.21) was not significantly different compared to those with catheters. However, all-cause mortality in the AVF group was lower compared to patients initiated on HD with catheters (HR, 0.65; p = 0.001). AVF used at the initiation of HD was associated with lower rate of all-cause mortality after kidney transplantation compared to the catheter. The type of initial vascular access for hemodialysis was not associated with kidney allograft survival.

Genome-wide meta-analysis for serum calcium identifies significantly associated SNPs near the calcium-sensing receptor (CASR) gene.

Calcium has a pivotal role in biological functions, and serum calcium levels have been associated with numerous disorders of bone and mineral metabolism, as well as with cardiovascular mortality. Here we report results from a genome-wide association study of serum calcium, integrating data from four independent cohorts including a total of 12,865 individuals of European and Indian Asian descent. Our meta-analysis shows that serum calcium is associated with SNPs in or near the calcium-sensing receptor (CASR) gene on 3q13. The top hit with a p-value of 6.3 x 10(-37) is rs1801725, a missense variant, explaining 1.26% of the variance in serum calcium. This SNP had the strongest association in individuals of European descent, while for individuals of Indian Asian descent the top hit was rs17251221 (p = 1.1 x 10(-21)), a SNP in strong linkage disequilibrium with rs1801725. The strongest locus in CASR was shown to replicate in an independent Icelandic cohort of 4,126 individuals (p = 1.02 x 10(-4)). This genome-wide meta-analysis shows that common CASR variants modulate serum calcium levels in the adult general population, which confirms previous results in some candidate gene studies of the CASR locus. This study highlights the key role of CASR in calcium regulation.

Social adaptability index predicts kidney transplant outcome: a single-center retrospective analysis.

BACKGROUND: Social adaptability index (SAI) is the composite index of socioeconomic status based upon employment status, education level, marital status, substance abuse and income. It has been used in the past to define populations at higher risk for inferior clinical outcomes. The objective of this retrospective study was to evaluate the association of the SAI with renal transplant outcome. METHODS: We used data from the clinical database at the Beth Israel Deaconess Medical Center Transplant Institute, supplemented with data from United Network for Organ Sharing for the years 2001-09. The association between SAI and graft loss and recipient mortality in renal transplant recipients was studied using Cox model in the entire study population as well as in the subgroups based on age, race, sex and diabetes status. RESULTS: We analyzed 533 end-stage renal disease patients (mean age at transplant 50.8 ± 11.8 years, 52.2% diabetics, 58.9% males, 71.1% White). Higher SAI on a continuous scale was associated with decreased risk of graft loss [hazard ratio (HR) 0.89, P < 0.05, per 1 point increment in the SAI] and decreased risk of recipient mortality (HR 0.84, P < 0.01, per 1 point increment in the SAI). Higher SAI was also significantly associated with decreased risk for graft loss/recipient mortality in some study subgroups (age 41-65 years, males, non-diabetics). CONCLUSIONS: SAI has an association with graft and recipient survival in renal transplant recipients. It can be helpful in identifying patients at higher risk for inferior transplant outcome as a target population for potential intervention.

Access to renal transplantation in the diabetic population-effect of comorbidities and body mass index.

BACKGROUND: In this study, we hypothesized that higher level of comorbidity and greater body mass index (BMI) may mediate the association between diabetes and access to transplantation. METHODS: We used data from the United States Renal Data System (01/01/2000-24/09/2007; n = 619,151). We analyzed two outcomes using Cox model: (i) time to being placed on the waiting list or transplantation without being listed and (ii) time to transplantation after being listed. Two primary Cox models were developed based on different levels of adjustment. RESULTS: In Cox models adjusted for a priori defined potential confounders, history of diabetes was associated with reduced transplant access (compared with non-diabetic population) - both for wait-listing/transplant without being listed (hazard ratio, HR = 0.80, p < 0.001) and for transplant after being listed (HR = 0.72, p < 0.001). In Cox models adjusted for BMI and comorbidity index along with the potential confounders, history of diabetes was associated with shorter time to wait-listing or transplantation without being listed (HR = 1.07, p < 0.001), and there was no significant difference in time to transplantation after being listed (HR = 1.01, p = 0.42). CONCLUSION: We demonstrated that higher level of comorbidity and greater BMI mediate the association between diabetes and reduced access to transplantation.

Prior Coronary Artery Bypass Graft Surgery and Outcome After Percutaneous Coronary Intervention: An Observational Study From the Pan-London Percutaneous Coronary Intervention Registry.

Background Limited information exists regarding procedural success and clinical outcomes in patients with previous coronary artery bypass grafting (CABG) undergoing percutaneous coronary intervention (PCI). We sought to compare outcomes in patients undergoing PCI with or without CABG. Methods and Results This was an observational cohort study of 123 780 consecutive PCI procedures from the Pan-London (UK) PCI registry from 2005 to 2015. The primary end point was all-cause mortality at a median follow-up of 3.0 years (interquartile range, 1.2-4.6 years). A total of 12 641(10.2%) patients had a history of previous CABG, of whom 29.3% (n=3703) underwent PCI to native vessels and 70.7% (n=8938) to bypass grafts. There were significant differences in the demographic, clinical, and procedural characteristics of these groups. The risk of mortality during follow-up was significantly higher in patients with prior CABG (23.2%; P=0.0005) compared with patients with no prior CABG (12.1%) and was seen for patients who underwent either native vessel (20.1%) or bypass graft PCI (24.2%; P<0.0001). However, after adjustment for baseline characteristics, there was no significant difference in outcomes seen between the groups when PCI was performed in native vessels in patients with previous CABG (hazard ratio [HR],1.02; 95%CI, 0.77-1.34; P=0.89), but a significantly higher mortality was seen among patients with PCI to bypass grafts (HR,1.33; 95% CI, 1.03-1.71; P=0.026). This was seen after multivariate adjustment and propensity matching. Conclusions Patients with prior CABG were older with greater comorbidities and more complex procedural characteristics, but after adjustment for these differences, the clinical outcomes were similar to the patients undergoing PCI without prior CABG. In these patients, native-vessel PCI was associated with better outcomes compared with the treatment of vein grafts.

Outcomes after chronic total occlusion percutaneous coronary interventions: an observational study of 5496 patients from the Pan-London CTO Cohort.

BACKGROUND: Chronic total occlusions (CTO) are commonly encountered in patients undergoing coronary angiography; however, percutaneous coronary intervention (PCI) is infrequently performed owing to technical difficulty, the perceived risk of complications and a lack of randomized data. The aim of this study was to analyse the frequency and outcomes of CTO-PCI procedures in a large contemporary cohort of successive patients. PATIENTS AND METHODS: We undertook an observational cohort study of 48 234 patients with stable angina of which 5496 (11.4%) procedures were performed for CTOs between 2005 and 2015 at nine tertiary cardiac centres across London, UK. Outcome was assessed by in-hospital major adverse cardiac events and all-cause mortality at a median follow-up of 4.8 years (interquartile range: 2.2-6.4 years). RESULTS: Over time, there was an increase in the proportion of elective PCI procedures performed for CTOs, but no increase in the absolute number. Overall success rates increased over time (74.3% in 2005 to 81.5% in 2015; P=0.0003) despite an increase in case complexity (previous myocardial infarction, diabetes, renal failure, previous coronary artery bypass grafting, peripheral vascular disease and left ventricular impairment) that correlated with procedural advancements. Successful CTO PCI was associated with lower mortality [9.5%, 95% confidence interval (CI): 8.1-11.6 vs. 15.3%, 95% CI: 13.7-20.6, P<0.0001] that persisted after multivariate cox analysis (hazard ratio: 0.37, 95% CI: 0.25-0.62) and propensity matching (hazard ratio=0.36, 95% CI: 0.18-0.73, P=0.0005). CONCLUSION: Successful procedures were associated with lower mortality suggesting that the greater uptake of CTO PCI may improve clinical outcomes in a wider population than are currently being offered therapy.

Angiography Alone Versus Angiography Plus Optical Coherence Tomography to Guide Percutaneous Coronary Intervention: Outcomes From the Pan-London PCI Cohort.

OBJECTIVES: This study aimed to determine the effect on long-term survival of using optical coherence tomography (OCT) during percutaneous coronary intervention (PCI). BACKGROUND: Angiographic guidance for PCI has substantial limitations. The superior spatial resolution of OCT could translate into meaningful clinical benefits, although limited data exist to date about their effect on clinical endpoints. METHODS: This was a cohort study based on the Pan-London (United Kingdom) PCI registry, which includes 123,764 patients who underwent PCI in National Health Service hospitals in London between 2005 and 2015. Patients undergoing primary PCI or pressure wire use were excluded leaving 87,166 patients in the study. The primary endpoint was all-cause mortality at a median of 4.8 years. RESULTS: OCT was used in 1,149 (1.3%) patients, intravascular ultrasound (IVUS) was used in 10,971 (12.6%) patients, and angiography alone in the remaining 75,046 patients. Overall OCT rates increased over time (p < 0.0001), with variation in rates between centers (p = 0.002). The mean stent length was shortest in the angiography-guided group, longer in the IVUS-guided group, and longest in the OCT-guided group. OCT-guided procedures were associated with greater procedural success rates and reduced in-hospital MACE rates. A significant difference in mortality was observed between patients who underwent OCT-guided PCI (7.7%) compared with patients who underwent either IVUS-guided (12.2%) or angiography-guided (15.7%; p < 0.0001) PCI, with differences seen for both elective (p < 0.0001) and acute coronary syndrome subgroups (p = 0.0024). Overall this difference persisted after multivariate Cox analysis (hazard ratio [HR]: 0.48; 95% confidence interval [CI]: 0.26 to 0.81; p = 0.001) and propensity matching (hazard ratio: 0.39; 95% CI: 0.21 to 0.77; p = 0.0008; OCT vs. angiography-alone cohort), with no difference in matched OCT and IVUS cohorts (HR: 0.88; 95% CI: 0.61 to 1.38; p = 0.43). CONCLUSIONS: In this large observational study, OCT-guided PCI was associated with improved procedural outcomes, in-hospital events, and long-term survival compared with standard angiography-guided PCI.

Real-time magnetic resonance imaging-guided endovascular recanalization of chronic total arterial occlusion in a swine model.

BACKGROUND: Endovascular recanalization (guidewire traversal) of peripheral artery chronic total occlusion (CTO) can be challenging. X-ray angiography resolves CTO poorly. Virtually "blind" device advancement during x-ray-guided interventions can lead to procedure failure, perforation, and hemorrhage. Alternatively, MRI may delineate the artery within the occluded segment to enhance procedural safety and success. We hypothesized that real-time MRI (rtMRI)-guided CTO recanalization can be accomplished in an animal model. METHODS AND RESULTS: Carotid artery CTO was created by balloon injury in 19 lipid-overfed swine. After 6 to 8 weeks, 2 underwent direct necropsy analysis for histology, 3 underwent primary x-ray-guided CTO recanalization attempts, and the remaining 14 underwent rtMRI-guided recanalization attempts in a 1.5-T interventional MRI system. Real-time MRI intervention used custom CTO catheters and guidewires that incorporated MRI receiver antennae to enhance device visibility. The mean length of the occluded segments was 13.3+/-1.6 cm. The rtMRI-guided CTO recanalization was successful in 11 of 14 swine and in only 1 of 3 swine with the use of x-ray alone. After unsuccessful rtMRI (n=3), x-ray-guided attempts were also unsuccessful. CONCLUSIONS: Recanalization of long CTO is entirely feasible with the use of rtMRI guidance. Low-profile clinical-grade devices will be required to translate this experience to humans.

Real-time magnetic resonance imaging-guided stenting of aortic coarctation with commercially available catheter devices in Swine.

BACKGROUND: Real-time MR imaging (rtMRI) is now technically capable of guiding catheter-based cardiovascular interventions. Compared with x-ray, rtMRI offers superior tissue imaging in any orientation without ionizing radiation. Translation to clinical trials has awaited the availability of clinical-grade catheter devices that are both MRI visible and safe. We report a preclinical safety and feasibility study of rtMRI-guided stenting in a porcine model of aortic coarctation using only commercially available catheter devices. METHOD AND RESULTS: Coarctation stenting was performed wholly under rtMRI guidance in 13 swine. rtMRI permitted procedure planning, device tracking, and accurate stent deployment. "Active" guidewires, incorporating MRI antennas, improved device visualization compared with unmodified "passive" nitinol guidewires and shortened procedure time (26+/-11 versus 106+/-42 minutes; P=0.008). Follow-up catheterization and necropsy showed accurate stent deployment, durable gradient reduction, and appropriate neointimal formation. MRI immediately identified aortic rupture when oversized devices were tested. CONCLUSIONS: This experience demonstrates preclinical safety and feasibility of rtMRI-guided aortic coarctation stenting using commercially available catheter devices. Patients may benefit from rtMRI in the future because of combined device and tissue imaging, freedom from ionizing radiation, and the ability to identify serious complications promptly.

Real-time magnetic resonance-guided endovascular repair of experimental abdominal aortic aneurysm in swine.

OBJECTIVES: This study tested the hypotheses that endografts can be visualized and navigated in vivo solely under real-time magnetic resonance imaging (rtMRI) guidance to repair experimental abdominal aortic aneurysms (AAA) in swine, and that MRI can provide immediate assessment of endograft apposition and aneurysm exclusion. BACKGROUND: Endovascular repair for AAA is limited by endoleak caused by inflow or outflow malapposition. The ability of rtMRI to image soft tissue and flow may improve on X-ray guidance of this procedure. METHODS: Infrarenal AAA was created in swine by balloon overstretch. We used one passive commercial endograft, imaged based on metal-induced MRI artifacts, and several types of homemade active endografts, incorporating MRI receiver coils (antennae). Custom interactive rtMRI features included color coding the catheter-antenna signals individually, simultaneous multislice imaging, and real-time three-dimensional rendering. RESULTS: Eleven repairs were performed solely using rtMRI, simultaneously depicting the device and soft-tissue pathology during endograft deployment. Active devices proved most useful. Intraprocedural MRI provided anatomic confirmation of stent strut apposition and functional corroboration of aneurysm exclusion and restoration of laminar flow in successful cases. In two cases, there was clear evidence of contrast accumulation in the aneurysm sac, denoting endoleak. CONCLUSIONS: Endovascular AAA repair is feasible under rtMRI guidance. Active endografts facilitate device visualization and complement the soft tissue contrast afforded by MRI for precise positioning and deployment. Magnetic resonance imaging also permits immediate post-procedural anatomic and functional evaluation of successful aneurysm exclusion.

Factors predicting failure of AV "fistula first" policy in the elderly.

An arteriovenous fistula (AVF) is the preferential hemodialysis (HD) access. The goal of this study was to identify factors associated with pre-dialysis AVF failure in an elderly HD population. We used United States Renal Data System + Medicare claims data to identify patients ≥ 67 years old who had an AVF as their initial vascular access placed pre-dialysis. Failure of the AVF to be used for initial HD, was used as the outcome. Logistic regression model was used to identify factors associated with AVF failure. The study cohort consisted of 20,360 subjects (76.2 ± 6.02 year old, 58.5% men). Forty-eight percent of patients initiated dialysis using an AVF, while 52% used a catheter or an AVG. The following variables found to be associated with AVF failure when an AVF was created at least 4 months pre-HD initiation: older age (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.00-1.02), female gender (OR 1.69; 95% CI 1.55-1.83), black race (OR 1.41; 95% CI 1.26-1.58), history of diabetes (OR 1.22; 95% CI 1.06-1.39), cardiac failure (OR 1.26; 95% CI 1.15-1.37), and shorter duration of pre-end-stage renal disease (ESRD) nephrology care (OR for a nephrology care of less than 6 months prior to ESRD of 1.22 compared with a pre-ESRD nephrology follow up of more than 12 months; 95% CI 1.07-1.38). OR for AVF failure for the entire cohort showed similar findings. In an elderly HD population, there is an association of older age, female gender, black race, diabetes, cardiac failure and shorter pre-ESRD nephrology care with predialysis AVF failure.

Disparities in arteriovenous fistula placement in older hemodialysis patients.

The benefits of an arteriovenous fistula (AVF) as the preferred vascular access for hemodialysis have been clearly demonstrated. However, only about 20% of patients in the United States initiate hemodialysis with an AVF. In this study, we assessed whether disparities exist in the type of first hemodialysis access placed prior to dialysis start (rather than that used at dialysis initiation), to detect whether certain disadvantaged groups might have lower likelihood of AVF placement. Study cohort of 118,767 incident hemodialysis patients ≥67 years of age (1/2005-12/2008) derived from the United States Renal Data System was linked with Medicare claims data to identify the type of initial access placed predialysis. We used logistic regression model with outcome being the initial predialysis placement of an AVF as opposed to an arteriovenous graft or a central venous catheter. Increasing age, female sex, black race, lower body mass index, urban location, certain comorbidities, and shorter pre-end-stage renal disease nephrology care are all associated with a significantly lower likelihood of AVF placement as initial access predialysis. Our study suggests the presence of significant disparities in the placement of an AVF as initial hemodialysis vascular access. We suggest that additional attention should be paid to these patient groups to improve disparities by patient education, earlier referral, and close follow-up.

Geographic disparities in arteriovenous fistula placement in patients approaching hemodialysis in the United States.

Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis (HD). Several factors associated with AVF placement have been identified (e.g., age, sex, race, comorbidities). We hypothesized that geographic location of patient residence might be associated with the probability of AVF placement as the initial access. We used the data from the United States Renal Data System (USRDS) database (2005-2008) linked to Medicare claims (2003-2008). Logistic regression was used to estimate specific characteristics of population associated with the AVF as first access placed or attempted for HD initiation. Our primary variable of interest was the geographic location, and the multivariate model was adjusted for age, sex, race, body mass index, primary cause of end-stage renal disease (ESRD), duration of pre-ESRD nephrology care, comorbidities, employment status, substance abuse, and income. Geographic location was determined using the data collected by the RUCA project and divided population into metropolitan, micropolitan, and rural categories. Patients (n = 111,953) identified from the USRDS database with linked Medicare claims were examined. Rates of fistula placement in the metropolitan, micropolitan, and rural population were 18.5%, 22.4%, and 21.6%, respectively. In comparison, patients who received catheter as the first access were 81.5%, 77.6% and 78.4%, respectively. The odds ratio of AVF placement as a first HD access in the rural and metropolitan population compared with the micropolitan population were 0.96 (0.90-1.03; P = 0.26) and 0.80 (0.76-0.84; P < 0.001), respectively. Our results indicate the presence of geographic disparities in AVF placement with decreased rates of AVF as the first access created in the metropolitan (but not rural) populations compared with the micropolitan communities.