Ramon Roca-Tey

Starting hemodialysis with catheter and mortality risk: persistent association in a competing risk analysis.

Purpose The vascular access (VA) used at hemodialysis (HD) inception is involved in the mortality risk. We analyzed the survival of incident patients over time according to the initial VA and the VA profile of patients who died during the first year of follow-up. Methods Data of VA were obtained from 9956 incident HD patients from the Catalan Registry. Results Over 12 years, 47.9% of patients initiated HD with a fístula, 1.2% with a graft, 15.9% with a tunneled catheter and 35% with an untunneled catheter. Regarding fistula use, the hazard ratio of death for all-causes over time when applying a multivariate competing risk model was 1.55 [95% confidence interval (CI): 1.42-1.69] and 1.43 (95% CI: 1.33-1.54) for patients with tunneled and untunneled catheter, respectively. During the first year of follow-up, the crude all-cause mortality rate (deaths/100 patient-years) was higher during the early (first 120 days) compared to the late (121-365 days) period: 18.3 (95% CI: 16.8-19.8) versus 15.4 (95% CI: 14.5-16.5). Regarding fistula use, for patients using untunneled and tunneled catheter, the odds ratio of death in the early period for all-causes was 3.66 (95% CI: 2.80-4.81) and 2.97 (95% CI: 2.17-4.06), for cardiovascular causes it was 2.76 (95% CI: 1.90-4.01) and 1.84 (95% CI: 1.17-2.89) and for infection-related causes it was 6.62 (95% CI: 3.11-14.05) and 4.58 (95% CI: 2.00-10.52), respectively. Conclusions Half of all incident patients in Catalonia are exposed to excessive mortality risk related to catheter and this scenario can be improved by early fistula placement.

The impact of access blood flow surveillance on reduction of thrombosis in native arteriovenous fistula: a randomized clinical trial

Purpose The usefulness of access blood flow (QA) measurement is an ongoing controversy. Although all vascular access (VA) clinical guidelines recommend monitoring and surveillance protocols to prevent VA thrombosis, randomized clinical trials (RCTs) have failed to consistently show the benefits of QA-based surveillance protocols. We present a 3-year follow-up multicenter, prospective, open-label, controlled RCT, to evaluate the usefulness of QA measurement using Doppler ultrasound (DU) and ultrasound dilution method (UDM), in a prevalent hemodialysis population with native arteriovenous fistula (AVF). Methods Classical monitoring and surveillance methods are applied in all patients, the control group (n = 98) and the QA group (n = 98). Besides this, DU and UDM are performed in the QA group every three months. When QA is under 500 ml/min or there is a >25% decrease in QA the patient goes for fistulography, surgery or close clinical/surveillance observation. Thrombosis rate, assisted primary patency rate, primary patency rate and secondary patency rate are measured. Results After one-year follow-up we found a significant reduction in thrombosis rate (0.022 thrombosis/patient/year at risk in the QA group compared to 0.099 thrombosis/patient/year at risk in the control group [p = 0.030]). Assisted primary patency rate was significantly higher in the QA group than in control AVF (hazard ratio [HR] 0.23, 95% confidence interval [CI] 0.05-0.99; p = 0.030). In the QA group, the numbers unddergoing angioplasty and surgery were higher but with no significant difference in non-assisted primary patency rate (HR 1.41, 95% CI 0.72-2.84; p = 0.293). There was a non-significant improvement in secondary patency rate in the QA group (HR 0.510, 95% CI 0.17-1.50; p = 0.207). Conclusions The measurement of QA combining DU and UDM shows a reduction in thrombosis rate and an increased assisted primary patency rate in AVF after one-year follow-up. Trial registration ClinicalTrials.gov Identifier: NCT02111655.

Permanent arteriovenous fistula or catheter dialysis for heart failure patients

Heart failure (HF) is the most frequent cardiovascular disease associated with chronic kidney disease and represents a high risk for cardiovascular mortality in incident hemodialysis (HD) patients. This risk is especially high during the arteriovenous fistula (AVF) maturation period due to the marked hemodynamic changes related to the large increase in the blood flow and also within the first 120 days after HD inception because in this period the highest mortality rate occurs. When planning the vascular access for each incident HF patient, the risk of aggravating HF after AVF creation must be evaluated carefully alongside the risk of catheter-related complications, but avoiding a non-selective ‘catheter first’ approach for all these patients. HF patients classified within the New York Heart Association (NYHA) Class I-II and the American College of Cardiology/American Heart Association (ACC/AHA) Stage A-B could initiate HD through a distal arm AVF. High-flow brachial artery-based AVF creation must be avoided because it displays the highest risk of worsening the cardiac function. The decision for AVF creation or tunneled central catheter placement in HF patients classified within the NYHA Class III and the ACC/AHA Stage C must have been individualized according the degree of systolic and/or diastolic dysfunction. HF patients with significant reduction in systolic function (ejection fraction lower than 30%) or classified within the NYHA Class IV and the ACC/AHA Stage D, are candidates for tunneled catheter placement to start HD treatment.

Vascular access for incident hemodialysis patients in Catalonia: analysis of data from the Catalan Renal Registry (2000-2011).

Purpose Arteriovenous fístula is the best vascular access (VA) for hemodialysis. We analyzed the VA used at first session and the factors associated with the likelihood to start hemodialysis by fistula in 2000-2011. Methods Data of VA type were obtained in 9,956 incident hemodialysis patients from the Catalan Registry. Results Overall, 47.9% of patients initiated hemodialysis with a fistula, 1.2% with a graft, 15.9% with a tunneled catheter and 35% with an untunneled catheter. The percentage of incident patients with fistula and catheter has remained stable at around 50% over the years. The likelihood to start hemodialysis with fistula was significantly lower in females [adjusted odds ratio: 0.69, 95% confidence interval (CI): 0.61-0.75], patients aged 18-44 years (0.78, 95% CI: 0.64-0.94), patients with comorbidity (0.67, 95% CI: 0.60-0.75) and tended to be lower in patients aged over 74 years (0.89, 95% CI: 0.78-1.01). The probability to use fistula was significantly higher in patients with polycystic kidney disease (2.08, 95% CI: 1.63-2.67), predialysis nephrology care longer than 2 years (4.14, 95% CI: 3.63-4.73) and steady chronic kidney disease (CKD) progression (10.97, 95% CI: 8.41-14.32). During 1 year of follow-up, 67.2% and 59.6% of patients using untunneled and tunneled catheter changed to fistula, respectively. Conclusions Starting hemodialysis by fistula was related with nonmodifiable patient characteristics and modifiable CKD practice processes, such as predialysis care duration. Half of the incident patients were exposed annually in Catalonia to potential catheter complications. This scenario can be improved by optimizing the processes of CKD care.

Adding access blood flow surveillance reduces thrombosis and improves arteriovenous fistula patency: a randomized controlled trial

Purpose Stenosis is the main cause of arteriovenous fistula (AVF) failure. It is still unclear whether surveillance based on vascular access blood flow (QA) enhances AVF function and longevity. Methods We conducted a three-year follow-up randomized, controlled, multicenter, open-label trial to compare QA-based surveillance and pre-emptive repair of subclinical stenosis with standard monitoring/surveillance techniques in prevalent mature AVFs. AVFs were randomized to either the control group (surveillance based on classic alarm criteria; n = 104) or to the QA group (QA measured quarterly using Doppler ultrasound [M-Turbo®] and ultrasound dilution [Transonic®] added to classic surveillance; n = 103). The criteria for intervention in the QA group were: 25% reduction in QA, QA<500 mL/min or significant stenosis with hemodynamic repercussion (peak systolic velocity [PSV] more than 400 cm/sc or PSV pre-stenosis/stenosis higher than 3). Results At the end of follow-up we observed a significant reduction in the thrombosis rate in the QA group (0.025 thrombosis/patient/year in the QA group vs. 0.086 thrombosis/patient/year in the control group [p = 0.007]). There was a significant improvement in the thrombosis-free patency rate (HR, 0.30; 95% CI, 0.11-0.82; p = 0.011) and in the secondary patency rate in the QA group (HR, 0.49; 95% CI, 0.26-0.93; p = 0.030), with no differences in the primary patency rate between the groups (HR, 0.98; 95% CI, 0.57-1.61; p = 0.935). There was greater need for a central venous catheter and more hospitalizations associated with vascular access in the control group (p = 0.034/p = 0.029). Total vascular access-related costs were higher in the control group (€227.194 vs. €133.807; p = 0.029). Conclusions QA-based surveillance combining Doppler ultrasound and ultrasound dilution reduces the frequency of thrombosis, is cost effective, and improves thrombosis free and secondary patency in autologous AVF.

Five years of vascular access stenosis surveillance by blood flow rate measurements during hemodialysis using the Delta-H method.

Purpose To report experience over five years of vascular access (VA) stenosis surveillance. Methods We prospectively monitored the blood flow rate (QA) of 145 VA in 131 ESRD (age 62.6 ±13.5 y) patients (pts). QA measurement: within the first hour of the hemodialysis (HD) session by the Delta-H method using the Crit Line III Monitor. All VA with baseline QA < 700 mL/min or decreased > 20% from baseline over time met the positive evaluation (PE) criteria and were referred for angiography (AG) plus elective intervention if stenosis ≥ 50%. Results We found 54 cases of PE in 47 VA; the AG was performed in 87% (47/54) cases of PE and most of them (43/47, positive predictive value: 91.5%) showed significant stenosis (mean degree 80.5 ±12.9%). Mean QA increased from 554.7±107.6 mL/min to 977.9 ± 359.9 mL/min just before versus after preventive intervention (P<.001). Without difference when comparing the highest QA reported before stenosis development (889.8 ± 409.5 mL/min) and the QA recorded just post-intervention (P=.18). Kt/V index: improved from 1.43 ± 0.22 to 1.49 ± 0.21 just before versus after intervention (P=.006). Conclusions 1) The Delta-H technique is an accurate method for early diagnosis of VA stenosis and is useful in monitoring the hemodynamic effect of elective VA treatment. 2) After preventive intervention for stenosis, functional VA status is restored and HD delivery is improved.

Guía Clínica Española del Acceso Vascular para Hemodiálisis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Fe de errores de «Guía Clínica Española del Acceso Vascular para Hemodiálisis»

José Ibeasa,∗, Ramon Roca-Teyb, Joaquín Vallespín c, Teresa Morenod, Guillermo Moñux e, Anna Martí-Monrós f, José Luis del Pozog, Enrique Grussh, Manel Ramírez de Arellano i, Néstor Fontseré j, María Dolores Arenask, José Luis Merino l, José García-Revillom, Pilar Caron, Cristina López-Espada , Antonio Giménez-Gaibar c, Milagros Fernández-Lucas o, Pablo Valdésp, Fidel Fernández-Quesada , Natalia de la Fuenteq, David Hernán r, Patricia Arribas s, María Dolores Sánchez de la Nieta t, María Teresa Martínezu, Ángel Barbaq y por el Grupo Español Multidisciplinar del Acceso Vascular (GEMAV)

Dialysis arteriovenous access monitoring and surveillance according to the 2017 Spanish Guidelines

The Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology (S.E.N.), vascular surgery (SEACV), interventional radiology (SERAM-SERVEI), infectious diseases (SEIMC), and nephrology nursing (SEDEN)), along with the methodological support of the Iberoamerican Cochrane Centre, has developed the Spanish Clinical Guidelines on Vascular Access for Hemodialysis. This article summarizes the main issues from the guideline’s chapter entitled “Monitoring and surveillance of arteriovenous access.” We will analyze the current evidence on conflicting topics such as the value of the flow-based screening methods for the arteriovenous access surveillance or the role of Doppler ultrasound as the imaging exploration to confirm suspected stenosis. In addition, the concept of significant stenosis and the criteria to perform the elective intervention for stenosis were reviewed. The adoption of these guidelines will hopefully translate into a reduced risk of thrombosis and increased patency rates for both arteriovenous fistulas and grafts.