Is endovascular arteriovenous fistula a feasible alternative for hemodialysis patients?

INTRODUCTION: For hemodialysis (HD) patients, the selection of vascular access (VA) is a crucial factor that significantly affects morbidity and mortality. Historically, native Arteriovenous Fistulas (AVFs) have been established using surgical techniques. However, devices facilitating percutaneous endovascular arteriovenous fistula formation have recently been introduced in clinical practice, showing promising initial evidence. The primary objectives were technical success, efficacy, and cannulation rates. The secondary objectives included primary and cumulative patency, safety, and the number of procedures required to maintain fistula patency. METHODS: A prospective, single-center, single-arm study that included all patients who underwent endovascular arteriovenous fistulas (endoAVF) creation using the WavelinQ™ EndoAVF System at a University Hospital between December 2021 and August 2023. RESULTS: A total of 20 patients who underwent an endoAVF were included. Technical success was 100%. 75% (15) of the endoAVFs met the criteria for physiological suitability. The cannulation rate was 66% (10/15) for endoAVFs that reached physiological suitability. At 6 months of follow-up, the primary and cumulative patency rates were 65% and 75%, respectively; at 12 months, these were 50% and 70%, respectively. Serious adverse events were not observed. The reintervention rate was 0.33 procedures/patient-year. CONCLUSION: Based on our experience, creating AVFs using the WavelinQ 4-F EndoAVF system is safe and effective, with high technical success rates and acceptable patency and reintervention rates.

Is Expanded Hemodialysis an Option to Online Hemodiafiltration for Small- and Middle-Sized Molecules Clearance?

BACKGROUND: Recent evidence suggests a better reduction rate of some uremic toxins with expanded hemodialysis (HDx). METHODS: Prospective study including 8 hemodialysis patients. We divided the study in 2 phases; within the first one, we assigned 4 patients (group 1) to undergo online hemodiafiltration with a PF 210H dialyzer, and the other 4 patients (group 2) to undergo HDx with the high retention onset Theranova 500 dialyzer during 24 sessions. Later, during the second phase and after a washout period, the same patients were switched to receive HDx (group 1) and HDF (group 2). RESULTS: No differences were found in the Urea and ß2-microglobulin reduction ratio. However, in the case of myoglobin, the reduction ratio with HDF was 35 vs. 60% with HDx (p < 0.001). Similarly, in the case of prolactin, the reduction ratio with HDF was 45 and 61% with HDx (p < 0.001). CONCLUSIONS: We conclude that HDx is not inferior to online hemodiafiltration in the clearance of small and middle molecules and could be superior in the clearance of larger middle molecules.

Pulmonary Hypertension Is Associated with Mortality and Cardiovascular Events in Chronic Kidney Disease Patients.

BACKGROUND: We evaluated the prevalence, determinants and prognosis value of pulmonary hypertension (PH) in non-dialysis chronic kidney disease (CKD) patients. METHODS: This is a prospective study with stages 3-5 non-dialysis-dependent CKD patients. PH was estimated by Doppler echocardiography and defined as a pulmonary artery systolic pressure above 35 mm Hg. RESULTS: Three hundred fifty-three patients were recruited, of whom 94 (26.6%) had PH. Prevalence of PH increased with the decline of renal function: 21.6, 24.1, and 31.7% in stages 3, 4, and 5, respectively. Independent predictors of PH were age, estimated glomerular filtration rate (eGFR), history of cardiovascular (CV) events, the presence of an arteriovenous fistulae (AVF), and left ventricular (systolic and diastolic) dysfunction. Over a median follow-up of 22 months, 71 patients died (20%). After multivariate adjustment for age, gender, previous CV disease, diastolic and systolic dysfunction, PH remained as an independent predictor of all-cause mortality (hazards ratio [HR] 1.84, 95% CI 1.06-3.18, p = 0.02). One hundred patients (28%) had a new onset CV event. After adjustment for age, gender, previous CV disease, systolic and diastolic dysfunction, PH maintains its independent association with CV events (HR 2.77, 95% CI 2.00-3.25, p < 0.001). CONCLUSIONS: PH prevalence rises as kidney function declines. Main determinants of PH are age, eGFR, previous CV disease, the presence of an AVF and left ventricular systolic or diastolic dysfunction. PH is an independent predictor of all-cause mortality and CV events.

Pulmonary hypertension is an independent predictor of cardiovascular events and mortality in haemodialysis patients.

AIM: The evidence about prevalence, associated factors of pulmonary hypertension (PH) and its impact on patient's outcomes is limited. METHODS: We included 211 haemodialysis patients, we estimated the systolic pulmonary artery pressure (SPAP) by 2D Doppler echocardiography defining PH as a SPAP above 35 mmHg, the median follow-up was 39 (19-56) moths, and the primary endpoints were all cause mortality and cardiovascular events. RESULTS: We found PH in 91 patients (43.9%). Independent determinants of PH were age, previous cardiovascular disease, the Nt-pro-BNP level hs-TnT, the systolic dysfunction, diastolic dysfunction and left ventricular hypertrophy. Over the follow-up 94 cardiovascular events occurred, variables associated were: PH, age, history cardiovascular disease, dyslipidaemia, elevated concentration of Nt-pro-BNP and hs-TnT, systolic and diastolic dysfunction, in a multivariate model, the PH maintained its independent association. Mortality data: 88 patients died (41.7%); 35 (29.5%) in the no PH group and 53 (58.5%) in the PH group (P < 0.001). In the Cox survival analysis, we found an association between mortality and age, previous cardiovascular disease, history of peripheral vascular disease, Nt-pro-BNP levels. In a multivariate model the PH remains as independent predictor of mortality. CONCLUSIONS: Pulmonary hypertension is a common finding in HD patients and a valuable predictor of mortality and cardiovascular events. Prospective studies are needed to assess the effect of intervention on risk factors in improving patient's outcomes.

Detection of patients at high risk for non-occlusive mesenteric ischemia in hemodialysis.

BACKGROUND: Nonocclusive mesenteric ischemia (NOMI) is an emerging condition in hemodialysis (HD) patients not widely studied. MATERIALS AND METHODS: A retrospective study was conducted between 2003 and 2011. NOMI cases were recorded, and demographic, clinical, biochemical, and HD parameters were collected. This group was compared with a control group (n = 93). Risk factors, prognosis, and survival were analyzed. RESULTS: There were 57 episodes of NOMI (incidence, 2.29 episodes per 100 patients/y). Cecum was the most frequently affected segment. Nineteen patients (33%) underwent surgery. Twenty-six patients (59%) did not survive the acute episode. Cecal damage was the only protective factor associated with mortality (relative risk [RR], 0.712; P = 0.044). The incidence of NOMI was related to erythropoietin resistance index, diabetes mellitus, and longer time on HD compared with control group (RR, 6.92, P = 0.009; RR, 9.98, P = 0.005; and RR, 1.017, P < 0.001, respectively). Mortality in survival NOMI patients was higher at 4-y follow-up compared with that in the control group (log-rank, 15.5; P < 0.0001). CONCLUSIONS: NOMI is associated with erythropoietin resistance index, diabetes mellitus, and longer time on HD. Hypotension must be avoided in these high-risk patients to prevent NOMI.

Diastolic dysfunction and high levels of new cardiac biomarkers as risk factors for cardiovascular events and mortality in hemodialysis patients.

BACKGROUND/AIMS: Cardiovascular events (CVEs) are the most frequent cause of death in hemodialysis (HD). We aim to determine cardiovascular and mortality risk factors. METHODS: A historical cohort study was made of 211 prevalent HD patients [73 (60-80) years, 58% males] between 2005 and 2012. Demographic, laboratory test and echocardiographic values were recorded. During follow-up, CVEs and mortality were documented and analyzed. RESULTS: 94 patients suffered a CVE. Age, history of cardiovascular disease (CVD), peripheral vascular disease, cardiac markers, systolic and diastolic dysfunction (DD) were associated to CVEs. Low albumin (RR 0.414, p = 0.002), DD (1.876, p = 0.038) and previous CVD (3.723, p < 0.001) were identified as independent predictors of CVEs. 98 patients died. Age, a history of CVD, peripheral vascular disease, cardiac markers, DD, dialysis vintage, and a vascular access different from autologous fistulae were associated to mortality. Low albumin (RR 0.499, p = 0.046), DD (RR 2.414, p = 0.017) and a vascular access different from autologous fistulae (RR 2.058, p = 0.034) were independent predictors of mortality. CONCLUSIONS: DD is an emergent risk factor for death and CVEs in dialysis. Low albumin is also a predictor for CVE. Non-autologous fistulae and low albumin are predictors for death. Nt-proBNP and hsTnT offer good information for identifying high-risk patients, but they do not predict events independently as they are only cardiac damage markers.

Expanded hemodialysis: what's up, Doc?

In recent years there has been an increasing interest in expanded hemodialysis (HDx), an emerging renal replacement therapy based on the use of medium cut-off membranes (MCO). Thanks to the internal architecture of these types of membranes, with a higher pore size and smaller fiber inner diameter to favor internal filtration rate, they can increase the removal of larger middle molecules in conventional hemodialysis. Secondarily, several reports suggest that this therapy potentially improve the outcomes for end-stage renal disease patients. However, HDx has not been defined yet and the characteristics of MCO membranes are not well stablished. The aim of this narrative review is to define HDx and summarize the dialyzers that have been used so far to perform this therapy, collect the evidence available on its efficacy and clinical outcomes compared with other hemodialysis techniques and settle the bases for its optimal prescription.

Utility of bioimpedance spectroscopy (BIS) in the management of refractory hypertension in patients with chronic kidney disease (CKD).

BACKGROUND: Expansion of extracellular volume (ECV) is a frequent cause of resistant hypertension (RHT) in patients with chronic kidney disease (CKD). The aim of this exploratory study was that of applying bioimpedance spectroscopy (BIS) for the identification of CKD patients with RHT and expansion of ECV, while trying to control blood pressure (BP) using an intensification of diuretic treatment. METHODS: We included 50 patients with RHT and CKD who underwent BIS. In order to control BP, diuretic treatment was intensified in those patients with expansion of the ECV. In all other cases, another antihypertensive drug was added. RESULTS: The mean age was 68.2 ± 10.4 years, 68% were male and 58% were diabetic. The mean estimated glomerular filtration rate (eGFR) was 50.7 ± 22.4 mL/min/1.72 m(2). Baseline systolic BP was 167.2 ± 8.6 mmHg and diastolic BP was 84.8 ± 9.5 mmHg. The mean number of antihypertensive drugs received was 3.8 ± 0.9. Expansion of ECV was recorded in 30 (60%) patients and was more frequent in diabetics and in patients with more albuminuria. At 6 months of follow-up, a decline of 21.4 ± 7.1 mmHg was observed in systolic BP in the patients with expansion of ECV, compared with a decrease of 9.4 ± 3.4 mmHg in the normal ECV group (P < 0.01). We did not find differences in the decrease in diastolic BP between the groups. Nine patients (30%) with ECV expansion who increased diuretic therapy reached the target blood pressure (BP) of <140/90 mmHg, when compared with only two patients (10%) who had normal ECV and in whom other antihypertensive drug was added. A total decrease in body water of 1.9 ± 1.1 L was observed in patients with ECV expansion who intensified diuretic treatment at the expense of a decline in ECV of 1.1 ± 1 L. eGFR remained stable in both groups (47.1 ± 21.1 versus 54.1 ± 25.2 mL/min/1.73 m(2); P = 0.37). CONCLUSIONS: An increase in ECV as measured by BIS frequently occurs in RHT in patients with CKD. Diabetic and severe proteinuric patients are more exposed to expansion of ECV. BIS is a potentially useful method for identifying and treating patients with RHT and expansion of ECV. The hypothesis generated by this exploratory study needs to be tested in a randomized clinical trial.

Intraindividual interleukin-6 variations on the cardiovascular prognosis of patients with chronic renal disease.

In chronic kidney disease (CKD) patients on dialysis, plasma interleukin (IL)-6 levels predict mortality better than other markers. Impact of intraindividual changes of inflammatory markers on cardiovascular (CV) events in CKD patients is unknown. The aim of this study is to demonstrate the relation between CV outcomes and variations of C-reactive protein (CRP), IL-6, IL-1ß, and tumor necrosis factor (TNF)-α in CKD. Ninety patients (mean age: 68.5 ± 12.8 years) at different stages (1-4) of CKD were evaluated. Serum CRP, IL-6, IL-1ß, and TNF-α were measured basally and after taking statins or angiotensin II receptor blockers. Three patterns were defined for each marker (baseline, mean of two measurements, and variation of the marker: increase or decrease after 6 months). During follow-up (mean time: 72.7 ± 19.8 months), 14 patients died, 11 were included on dialysis program, and 29 suffered a CV event. Patients with persistently elevated IL-6 values had higher risk to develop CV events [OR = 1.21 (1.11-1.32), p = 0.001]. Mean of two measurements of IL-6 was a better predictor for events than a single measurement of IL-6, CRP, TNF-α, and IL-1ß. A mean of two determinations of plasma IL-6 greater than 6 pg/mL and previous peripheral vascular disease was related to an increased risk for CV events [2.34 (1.05-5.22), p = 0.037 and 2.95 (1.27-6.93), p = 0.011, respectively] in an adjusted Cox regression model. IL-6 is a better inflammatory marker than CRP, TNF-α, and IL1ß at predicting CV events in CKD nondialysis patients. Mean of two measurements is better than simple determinations at predicting CV outcome.

Candida auris Invasive Infection after Kidney Transplantation.

INTRODUCTION: C. auris has been associated not only with a variety of invasive fungal infections, including candidemia, sometimes related to central venous catheter, but also with pericarditis and respiratory tract and urinary tract infections. MATERIALS AND METHODS: We describe the case of a patient with persistent fever despite antibiotics, who presented with Candida isolation in blood cultures, typified as Candida auris species. RESULTS: A 57-year-old male receiving peritoneal dialysis underwent kidney transplantation which was complicated by primary nonfunction due to arterial thrombosis necessitating graft nephrectomy. During the postoperative period, he presented with Pseudomonas aeruginosa pneumonia that was treated with levofloxacin and catheter-related Enterococcus faecalis bacteremia treated with linezolid. After hospital discharge, he then presented with herpes zoster infection treated with valacyclovir. Ten days later, he developed peritonitis and exit site infection with multidrug-resistant Pseudomonas aeruginosa treated with intraperitoneal aztreonam and peritoneal dialysis catheter removal. Despite broad-spectrum antibiotic therapy, the patient remained febrile. All microbiology laboratory tests were negative, so it was decided to stop antibiotic therapy for 48 hours and repeat cultures in order to avoid possible false negatives. In new blood cultures performed after suspension of antibiotic therapy, candidemia was observed, later typified as Candida auris species. After completing antifungal treatment (three weeks with intravenous amphotericin B 100 mg qd and two weeks of intravenous anidulafungin 100 mg qd), microbiological cultures remained negative and the patient made uneventful recovery. CONCLUSION: Candida auris invasive infection has been mainly described in patients with severe underlying comorbidities and immunocompromise. Multidrug-resistant clusters of Candida auris are increasingly emerging.

Oral Anticoagulation in Patients with Chronic Kidney Disease and Non-Valvular Atrial Fibrillation: The FAERC Study.

Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and its presence is associated with a higher risk of stroke and mortality. MATERIAL AND METHODS: The FAERC study performed a retrospective multicentre analysis of historical cohorts in which data were collected from arrhythmia diagnosis onwards. RESULTS: We analysed a Spanish cohort of 4749 patients with CKD (mean eGFR 33.9 mL/min) followed up in the nephrology clinic, observing a 12.2% prevalence of non-valvular AF. In total, 98.6% of these patients were receiving anticoagulant treatment, mainly with coumarins (79.7%). Using direct-acting oral anticoagulants (DOACs) was associated with fewer cerebrovascular events than using acenocoumarol, but in contrast with other studies, we could not corroborate the association of risk of bleeding, coronary events, or death with a type of anticoagulant prescribed. CONCLUSIONS: Atrial fibrillation is highly prevalent in renal patients. Direct-acting anticoagulants seem to be associated with fewer ischemic-embolic complications, with no differences in bleeding, coronary events, or mortality rates.

Lipid profile of patients treated with evolocumab in Spanish hospital nephrology units (RETOSS NEFRO).

BACKGROUND AND OBJECTIVE: To describe the clinical characteristics, the reasons for initiating therapy and the effects of treatment in the initial phase of evolocumab availability in the Nephrology Units of Spain. MATERIAL AND METHODS: Retrospective, observational and multicentric study that included patients initiating treatment with evolocumab (from February 2016 to August 2018), in 15 Nephrology Units in Spain. The demographic and clinical characteristics of the patients, the lipid lowering treatment and the evolution of the lipid profiles between 24 weeks pre-initiation and 12±4 weeks post-initiation of evolocumab were reviewed. RESULTS: 60 patients were enrolled: 53.3% women; mean (SD) age, 56.9 (12.8) years, 45.0% with familial hypercholesterolemia (FH) (5.0% homozygous and 40.0% heterozygous) and 65.0% with atherosclerotic cardiovascular disease. The mean (SD) eGFR was 62.6 (30.0) ml/min/1.73m2 (51.7% of patients had eGFR <60ml/min/1.73m2 [CKD stage>2]), 50.0% had proteinuria (>300mg/g) and 10.0% had nephrotic syndrome. Other CV risk factors were hypertension (75.0%), diabetes (25.0%), and smoking (21.7%). A 40.0% of patients were statin intolerant. At evolocumab initiation, 41.7% of patients were on a high intensity statin, 18.3% on moderate intensity statin and 50.0% were receiving ezetimibe. Mean (SD) LDL-c at evolocumab initiation was 179.7 (62.9) mg/dL (53.4% of patients with LDL-c ≥160mg/dL and 29.3% ≥190mg/dL). After 12 weeks, evolocumab resulted in LDL-c reductions of 60.1%. At week 12, 90.0% of patients reached LDL-c levels <100mg/dL, 70.0% <70mg/dL, and 55.0% <55mg/dL, while mean eGFR levels and statin use remained stable. CONCLUSION: In Nephrology Units of Spain, evolocumab was predominantly prescribed in patients with FH, chronic renal disease (CRD>2) and secondary prevention, with LDL-c levels above those recommended by the guidelines. Evolocumab used in clinical practice significantly reduced the LDL-c levels in all patients included in the study.

Proteinuria-Lowering Effects of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors in Chronic Kidney Disease Patients: A Real-World Multicentric Study.

Control of dyslipidemia in chronic kidney disease (CKD) is not always guaranteed with statins and/or ezetimibe. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have opened up a new era in lipid control, but their effect on renal function and proteinuria in real life have not yet been evaluated. The aim of the present study was to analyze the evolution of renal function and proteinuria in a cohort of CKD patients treated with PCSK9i. This retrospective multicentric cohort study included CKD patients treated with PCSK9i. Baseline epidemiological data, comorbidities and laboratory findings (including estimated glomerular filtration rate [eGFR], proteinuria and lipid profile) were collected. The evolution of renal function, proteinuria and lipid profile was analyzed during the 1-year follow-up. The cohort included 76 patients (68% male, mean age 66 ± 10 years). The mean baseline creatinine was 1.55 ± 0.77 mg/dL, and the mean eGFR was 52 ± 22 mL/min/1.73 m2. Reductions in LDL-cholesterol, total cholesterol and triglycerides during the first month were 51 ± 25%, 32 ± 25% and 11 ± 40%, respectively, levels that remained stable throughout the first year (p < 0.001 for LDL-cholesterol and total cholesterol trends and p = 0.002 for triglyceride trend). During follow-up, proteinuria improved from 57 (9-481) to 30 (7-520) mg/g (p = 0.021). In addition, eGFR remained stable, and no adverse events were reported. In our cohort, dyslipidemia treatment with PCSK9i was associated with decreased proteinuria in CKD patients, an effect that might be due to reduced lipid nephrotoxicity. Clinical trials are needed to further investigate whether this impact on proteinuria can significantly slow CKD progression in the long term.

Finerenone: A Potential Treatment for Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) affects an estimated 463 million people worldwide, equivalent to 1 in 11 adults. Moreover, the rapid growth of this disease has resulted in a high incidence of diabetic kidney disease (DKD), which, together with hypertension, is the main cause of chronic kidney disease (CKD). Hyperglycaemia, low-grade inflammation, altered lipid metabolism and hyperactivation of the renin-angiotensin-aldosterone system (RAAS) seem to be interrelated mechanisms contributing to both T2DM and microvascular complications. The introduction of drugs such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists has improved the ability to slow the progression of DKD, and has also demonstrated benefits in cardiovascular disease. Beyond the effects of these novel antidiabetic drugs, a body of evidence suggests that the overactivation of the mineralocorticoid receptor also contributes to CKD progression. Moreover, new and ongoing trials have demonstrated that the selective nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone improves the risk of CKD progression and cardiovascular events in patients with CKD and T2DM and optimized RAAS blockade. We review the rationale for the development and use of MRA drugs to slow CKD progression in patients with DKD, as well as other pleiotropic effects, and highlight the warnings associated with these agents.

SARS-CoV-2 vs. Hepatitis Virus Infection Risk in the Hemodialysis Population: What Should We Expect?

Since the dramatic rise of the coronavirus infection disease 2019 (COVID-19) pandemic, patients receiving dialysis have emerged as especially susceptible to this infection because of their impaired immunologic state, chronic inflammation and the high incidence of comorbidities. Although several strategies have thus been implemented to minimize the risk of transmission and acquisition in this population worldwide, the reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence varies across studies but is higher than in the general population. On the contrary, the screening for hepatitis viruses (HBV and HCV) has seen significant improvements in recent years, with vaccination in the case of HBV and effective viral infection treatment for HCV. In this sense, a universal SARS-CoV-2 screening and contact precaution appear to be effective in preventing further transmission. Finally, regarding the progress, an international consensus with updated protocols that prioritize between old and new indicators would seem a reasonable tool to address these unexpended changes for the nephrology community.

Lipid profile of patients treated with evolocumab in Spanish hospital nephrology units (RETOSS NEFRO). / Perfil clínico de los pacientes tratados con evolocumab en unidades hospitalarias de nefrología en España (RETOSS-NEFRO).

BACKGROUND AND OBJECTIVE: To describe the clinical characteristics, the reasons for initiating therapy and the effects of treatment in the initial phase of evolocumab availability in the Nephrology Units of Spain. MATERIAL AND METHODS: Retrospective, observational and multicentric study that included patients initiating treatment with evolocumab (from February 2016 to August 2018), in 15 Nephrology Units in Spain. The demographic and clinical characteristics of the patients, the lipid lowering treatment and the evolution of the lipid profiles between 24 weeks pre-initiation and 12±4 weeks post-initiation of evolocumab were reviewed. RESULTS: Sixty patients were enrolled: 53.3% women; mean (SD) age, 56.9 (12.8) years, 45.0% with familial hypercholesterolemia (FH) (5.0% homozygous and 40.0% heterozygous) and 65.0% with atherosclerotic cardiovascular (CV) disease. The mean (SD) eGFR was 62.6 (30.0)ml/min/1.73m2 (51.7% of patients had eGFR<60ml/min/1.73m2 [CKD stage>2]), 50.0% had proteinuria (>300mg/g) and 10.0% had nephrotic syndrome. Other CV risk factors were hypertension (75.0%), diabetes (25.0%), and smoking (21.7%). A 40.0% of patients were statin intolerant. At evolocumab initiation, 41.7% of patients were on a high-intensity statin, 18.3% on moderate intensity statin and 50.0% were receiving ezetimibe. Mean (SD) LDL-c at evolocumab initiation was 179.7 (62.9)mg/dL (53.4% of patients with LDL-c≥160mg/dL and 29.3%≥190mg/dL). After 12 weeks, evolocumab resulted in LDL-c reductions of 60.1%. At week 12, 90.0% of patients reached LDL-c levels <100mg/dL, 70.0% <70mg/dL, and 55.0% <55mg/dL, while mean eGFR levels and statin use were remained stable. CONCLUSION: In Nephrology Units of Spain, evolocumab was predominantly prescribed in patients with FH, chronic renal disease (CRD>2) and secondary prevention, with LDL-c levels above those recommended by the guidelines. Evolocumab used in clinical practice significantly reduced the LDL-c levels in all patients included in the study.

Protein-bound toxins: added value in their removal with high convective volumes. / Toxinas unidas a proteínas: valor añadido en su eliminación con altos volúmenes convectivos.

Chronic kidney disease is associated with an increased risk of cardiovascular events. In recent years, protein-bound toxins have become more important due to their association with increased morbidity and mortality, characterised by inadequate clearance during dialysis. The purpose of this study is to assess the influence of high convective volumes on postdilution online haemodiafiltration (OL-HDF) on the removal of medium-sized molecules, small molecules and protein-bound molecules. MATERIAL AND METHODS: In forty postdilutional OL-HDF sessions, the reduction rates of toxins of different molecular weights were measured in 13 patients, including protein-bound molecules such as p-cresyl sulphate, indoxyl sulphate and homocysteine. RESULTS: Total convective volume was 28.3 (5.1) litres (range 16.3-38.0 litres). Mean reduction rate of protein-bound molecules was 44.4% (15.7%), 48.7% (14.1%) and 58.6% (8.8%) for p-cresyl sulphate, indoxyl sulphate and homocysteine, respectively. Moreover, a statistically significant direct association was found between the reduction rates of all three molecules, the replacement volume and the Kt/V. CONCLUSION: High convective volumes during postdilution OL-HDF are associated with increased removal of protein-bound uraemic toxins.

Creatine-kinase and dialysis patients, a helpful tool for stratifying cardiovascular risk?

BACKGROUND AND AIMS: Hemodialysis patients have an enhanced risk for cardiovascular events. Cardiac biomarkers provide useful information for stratifying their risk. However the prognosis value of creatine kinase MB isoenzyme (CKMB) has not yet been validated in this population. The aim of the present study is to determine the predictable value of CK-MB in hemodialysis. METHODS: A cohort of 211 hemodialysis patients (58.3% male, median age 73 (60-80) years) were followed for 39 (19-56) months. Cardiac biomarkers including CKMB were recorded at baseline. Factors associated to CKMB and prognosis value of this biomarker was studied. RESULTS: The median value of CKMB was 1 (1-2) ng/mL with no patient exceeding normal laboratory values. Previous heart disease, diabetes mellitus, peripheral vascular disease and systolic and diastolic dysfunction were associated with higher levels of CKMB. Ninety-four patients (44.5%) cardiovascular events were recorded. CKMB levels ≥2ng/mL was independently associated to cardiovascular events during the follow up after adjusting. Adding CKMB to a model including several variables for predicting cardiovascular events, resulted in 17% improvement in risk discrimination (IDI) with a relative IDI of 9.9% (p=0.04). CONCLUSIONS: CKMB is a good marker for stratifying cardiovascular risk in hemodialysis patients and adds prognosis information to other well known independent predictors for cardiovascular events.

[Pulmonary hypertension in hemodialysis patients: Prevalence and associated factors]. / Hipertensión pulmonar en pacientes en hemodiálisis: prevalencia y factores asociados.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension (PH) is a progressive disorder that can be caused by several underlying conditions or an intrinsic alteration of the pulmonary vasculature. Chronic increased pressure in the pulmonary vasculature leads to changes in the architecture of the vessels that can perpetuate PH and produce right ventricular dysfunction. These structural and functional alterations can decrease survival and quality of life of patients on hemodialysis; however, there is a lack of evidence about this problem in this population. The aim of this study is to establish the prevalence of PH in patients on hemodialysis and its association with specific factors related to this patient population. MATERIAL AND METHODS: We included 202 prevalent patients on hemodialysis for at least 6 months and who were clinically stable. We collected demographic data, routine laboratory parameters and data of 2D Doppler-echocardiography. PH was defined as a systolic pulmonary artery pressure (SPAP) estimated by Doppler ultrasound above 35mmHg. Hydration status was assessed by determining the plasma concentration of N-terminal pro brain natriuretic peptide (Nt-proBNP). RESULTS: PH prevalence was 37.1% (75 patients). The average SPAP in the entire study population was 32±12mmHg and in the group with PH it was 45±11mmHg. We found a direct and statistically significant correlation between the presence of PH and age (P=.001), time on renal replacement therapy (P=.04), the presence of systolic dysfunction (P=.007), diastolic dysfunction (P= 01), mitral valve disease (P=.01) and double mitral and aortic disease (P=.007). Volume overload was closely associated with PH, as demonstrated by the correlation between the SPAP and Nt-proBNP levels (P=.001). CONCLUSION: We conclude that prevalence of PH in hemodialysis patients is high. And one of the most important associated factors is volume overload. More studies are needed to establish the impact of PH on morbidity and mortality of patients and to assess whether a better volume control improves PH.

Asymptomatic Intradialytic Supraventricular Arrhythmias and Adverse Outcomes in Patients on Hemodialysis.

BACKGROUND AND OBJECTIVES: Supraventricular arrhythmias are associated with high morbidity and mortality. Nevertheless, this condition has received little attention in patients on hemodialysis. The objective of this study was to analyze the incidence of intradialysis supraventricular arrhythmia and its long-term prognostic value. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We designed an observational and prospective study in a cohort of patients on hemodialysis with a 10-year follow-up period. All patients were recruited for study participation and were not recruited for clinical indications. The study population comprised 77 patients (42 men and 35 women; mean age =58±15 years old) with sinus rhythm monitored using a Holter electrocardiogram over six consecutive hemodialysis sessions at recruitment. RESULTS: Hypertension was present in 68.8% of patients, and diabetes was present in 29.9% of patients. Supraventricular arrhythmias were recorded in 38 patients (49.3%); all of these were short, asymptomatic, and self-limiting. Age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08) and right atrial enlargement (hazard ratio, 4.29; 95% confidence interval, 1.30 to 14.09) were associated with supraventricular arrhythmia in the multivariate analysis. During a median follow-up of 40 months, 57 patients died, and cardiovascular disease was the main cause of death (52.6%). The variables associated with all-cause mortality in the Cox model were age (hazard ratio, 1.04 per year; 95% confidence interval, 1.00 to 1.08), C-reactive protein (hazard ratio, 1.04 per 1 mg/L; 95% confidence interval, 1.00 to 1.08), and supraventricular arrhythmia (hazard ratio, 3.21; 95% confidence interval, 1.29 to 7.96). Patients with supraventricular arrhythmia also had a higher risk of nonfatal cardiovascular events (hazard ratio, 4.32; 95% confidence interval, 2.11 to 8.83) and symptomatic atrial fibrillation during follow-up (hazard ratio, 17.19; 95% confidence interval, 2.03 to 145.15). CONCLUSIONS: The incidence of intradialysis supraventricular arrhythmia was high in our hemodialysis study population. Supraventricular arrhythmias were short, asymptomatic, and self-limiting, and although silent, these arrhythmias were independently associated with mortality and cardiovascular events.