High-Target Hemodiafiltration Convective Dose Achieved in Most Patients in a 6-Month Intermediary Analysis of the CONVINCE Randomized Controlled Trial.

Introduction: High convection volumes in hemodiafiltration (HDF) result in improved survival; however, it remains unclear whether it is achievable in all patients. Methods: CONVINCE, a randomized controlled trial, randomized patients with end-stage kidney disease 1:1 to high-dose HDF versus high-flux hemodialysis (HD) continuation. We evaluated the proportion of patients achieving high-dose HDF target: convection volume per visit of ≥23 l (range ±1 l) at baseline, month 3, and month 6. We compared baseline characteristics in the following 2 ways: (i) patients on target for all 3 visits versus patients who missed target on ≥1 visits and (ii) patients on target for all 3 visits or missing it once versus patients who missed target on ≥2 visits. Results: A total of 653 patients were randomized to HDF. Their mean age was 62.2 (SD 13.5) years, 36% were female, 81% had fistula vascular access, and 33% had diabetes. Across the 3 visits, 75 patients (11%), 27 patients (4%), and 11 patients (2%) missed the convection volume target once, twice, and thrice, respectively. Apart from diabetes, there were no apparent differences in patient characteristics between patients who always achieved the high-dose target (83%) and those who missed the target either once or more (17%) or twice or more (6%). Conclusion: Achieving high-dose HDF is feasible for nearly all patients in CONVINCE and could be maintained during the 6-month follow-up period. Apart from diabetes, there were no other indications for confounding by indication on multivariable analyses that may explain the potential survival advantage for patients receiving high-dose HDF.

The position of renal denervation in treatment of hypertension: an expert consensus statement.

Hypertension is an important risk factor for cardiovascular disease. In the Netherlands, there are approximately 2.8 million people with hypertension. Despite treatment recommendations including lifestyle changes and antihypertensive drugs, most patients do not meet guideline-recommended blood pressure (BP) targets. In order to improve BP control and lower the risk of subsequent cardiovascular events, renal sympathetic denervation (RDN) has been introduced and studied as a non-pharmacological approach. While early data on the efficacy of RDN showed conflicting results, improvements in treatment protocols and study design resulted in robust new evidence supporting the potential of the technology to improve patient care in hypertensive subjects. Recently, 5 randomised sham-controlled trials demonstrated the safety and efficacy of the technology. Modelling studies have further shown that RDN is cost-effective in the Dutch healthcare setting. Given the undisputable disease burden along with the shortcomings of current therapeutic options, we postulate a new, clearly framed indication for RDN as an adjunct in the treatment of hypertension. The present consensus statement summarises current guideline-recommended BP targets, proposed workup and treatment for hypertension, and position of RDN for those patients with primary hypertension who do not meet guideline-recommended BP targets (see central illustration).

Screening of cardiovascular agents in plasma with LC-MS/MS: A valuable tool for objective drug adherence assessment.

Adherence to cardiovascular preventive agents is important to prevent short and long term cardiovascular events. Recently, qualitatively compound screening using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has gained interest for drug adherence assessment in patients at high risk of cardiovascular events. Therefore, we developed and tested an assay including 52 compounds and metabolites, covering over 95% of the antihypertensive and antithrombotic agents available worldwide. Trichloroacetic acid was used as simple and fast method for protein precipitation. The assay was validated for lower limit of quantification (LLOQ), linearity, stability for freeze/thaw, room temperature, autosampler and matrix effects. The LLOQ for each compound was targeted under the population trough concentration (PTC) as reported in literature to assure high sensitivity for adherence detection. This was accomplished for 50 of 52 compounds with a LLOQ equal or lower compared to the PTC. Linearity was confirmed for all compounds (r2 > 0.995), except for acetylsalicylic acid (r2 = 0.991). For room temperature stability, 12 compounds showed degradation over 20% after 20 h. 3 compounds suffer from matrix effect with recoveries < 50%. After analytical validation, blood samples from 91 patients with difficult-to-treat hypertension were analyzed. Patients were unaware of adherence assessment. Adherence varied largely per agent and per concentration ratio (CR) (ratio of the detected concentration with LC-MS/MS and the PTC) cut-off value. Additionally, stratification by adherence group showed that the percentage of patients classified as non-adherent increased from 6.6% for qualitative analysis (pos/neg) to 19.8% for a CR cut-off of 0.5. The data imply that using the CR cut off values has a significant and relevant effect on patient adherence classification.

Quality of life as indicator of poor outcome in hemodialysis: relation with mortality in different age groups.

BACKGROUND: Physical, cognitive and psychosocial functioning are frequently impaired in dialysis patients and impairment in these domains relates to poor outcome. The aim of this analysis was to compare the prevalence of impairment as measured by the Kidney Disease Quality of Life- Short Form (KDQOL-SF) subscales between the different age categories and to assess whether the association of these subscales with mortality differs between younger and older dialysis patients. METHODS: This study included data from 714 prevalent hemodialysis patients, from 26 centres, who were enrolled in the CONvective TRAnsport STudy (CONTRAST NCT00205556, 09-12-2005). Baseline HRQOL domains were evaluated for patients <65 years, 65-74 years and over 75 years. Multivariable Cox proportional hazards analyses were performed to assess the relation between the separate domains and 2-year mortality. RESULTS: Emotional health was higher in patients over the age of 75 compared to younger patients (mean level 71, 73 and 77 for increasing age categories respectively, p = 0.02), whilst physical functioning was significantly lower in older patients (mean level 60, 48 and 40, p < 0.01). A low level of physical functioning (Hazard Ratio (HR) 1.72 [95%Confidence Interval (CI) 1.02-2.73]), emotional health (HR 1.85 [95% 1.30-2.63]), and social functioning (HR 1.59 [95% CI 1.12-2.26]), was individually associated with an increased 2-year mortality within the whole population. The absence of effect modification suggests no evidence for different relations within the older age groups. CONCLUSIONS: In dialysis patients, older age is associated with lower levels of physical functioning, whilst the level of emotional health is not associated with age. KDQOL-SF domains physical functioning, emotional health and social functioning are independently associated with mortality in prevalent younger and older hemodialysis patients.

[Renal denervation as treatment option for hypertension]. / Renale denervatie bij hypertensie.

The rationale behind catheter-based renal denervation is that afferent and efferent renal nerves play a role in the pathogenesis and maintenance of high blood pressure, and that this can be prevented by blocking the function of the renal nerves. Since the introduction of catheter-based renal denervation, several observational and a small number of randomised controlled trials have been conducted. The available evidence does not allow for a definitive conclusion regarding its efficacy. There have been no serious side-effects reported. The development of this treatment concept has not been finalised; new trials have just commenced or will start in the near future.

Individualized prediction of the effect of angiotensin receptor blockade on renal and cardiovascular outcomes in patients with diabetic nephropathy.

AIMS: To predict individualized treatment effects of angiotensin receptor blockers (ARBs) on cardiovascular and renal complications in order to help clinicians and patients assess the benefit of treatment (or adherence) and estimate remaining disease risk. MATERIALS AND METHODS: In patients with diabetic nephropathy, the 3-year treatment effect of ARBs was predicted in terms of absolute risk reduction (ARR) for end-stage renal disease (ESRD) and cardiovascular disease (CVD; i.e. myocardial infarction, stroke, hospitalization for heart failure) and all-cause mortality. Competing-risk-adjusted proportional hazard models were developed based on the Irbesartan Diabetic Nephropathy Trial (IDNT) and externally validated in the Reduction of Endpoints NIDDM with Angiotensin II Antagonist Losartan (RENAAL) trial. RESULTS: Predictors included in the model were age, sex, smoking sex, systolic blood pressure, urinary albumin/creatinine ratio, estimated glomerular filtration rate, albumin and phosphorus. The median predicted 3-year risk without treatment was 6.0% for ESRD and 28.0% for CVD and mortality. The median [interquartile range (IQR)] predicted 3-year ARR was 1.2 (0.4-3.1)% for ESRD and 2.2 (1.8-2.6)% for CVD and mortality, resulting in a combined ARR of 3.4 (2.4-5.5)%. The remaining disease risk was 4.7 (IQR 1.7-12.8)% for ESRD and 25.8% (IQR 20.3-31.9)% for CVD and mortality. CONCLUSIONS: The combined effects of ARBs on ESRD and CVD and mortality in patients with diabetic nephropathy vary considerably between patients. A substantial proportion of patients remain at high risk for both outcomes despite ARB treatment.

Safety and long-term effects of renal denervation: Rationale and design of the Dutch registry.

BACKGROUND: Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapy-resistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with regard to efficacy, safety, predictors for success and long-term effects. To answer these important questions, we initiated a Dutch RDN registry aiming to collect data from all RDN procedures performed in the Netherlands. METHODS: The Dutch RDN registry is an ongoing investigator-initiated, prospective, multicentre cohort study. Twenty-six Dutch hospitals agreed to participate in this registry. All patients who undergo RDN, regardless of the clinical indication or device that is used, will be included. Data are currently being collected on eligibility and screening, treatment and follow-up. RESULTS: Procedures have been performed since August 2010. At present, data from 306 patients have been entered into the database. The main indication for RDN was hypertension (n = 302, 99%). Patients had a mean office blood pressure of 177/100 (±29/16) mmHg with a median use of three (range 0-8) blood pressure lowering drugs. Mean 24-hour blood pressure before RDN was 157/93 (±18/13) mmHg. RDN was performed with different devices, with the Simplicity™ catheter currently used most frequently. CONCLUSION: Here we report on the rationale and design of the Dutch RDN registry. Enrolment in this investigator-initiated study is ongoing. We present baseline characteristics of the first 306 participants.

Optimization of the convection volume in online post-dilution haemodiafiltration: practical and technical issues.

In post-dilution online haemodiafiltration (ol-HDF), a relationship has been demonstrated between the magnitude of the convection volume and survival. However, to achieve high convection volumes (>22 L per session) detailed notion of its determining factors is highly desirable. This manuscript summarizes practical problems and pitfalls that were encountered during the quest for high convection volumes. Specifically, it addresses issues such as type of vascular access, needles, blood flow rate, recirculation, filtration fraction, anticoagulation and dialysers. Finally, five of the main HDF systems in Europe are briefly described as far as HDF prescription and optimization of the convection volume is concerned.

The effect of renal denervation on kidney oxygenation as determined by BOLD MRI in patients with hypertension.

OBJECTIVES: Renal denervation (RDN) is a promising therapy for resistant hypertension. RDN is assumed to decrease sympathetic activity. Consequently, RDN can potentially increase renal oxygenation. Blood oxygen level-dependent MRI (BOLD-MRI) provides a non-invasive tool to determine renal oxygenation in humans. The aim of the current study was to investigate the effect of RDN on renal oxygenation as determined by BOLD-MRI. METHODS: Patients with resistant hypertension or the inability to follow a stable drug regimen due to unacceptable side effects were included. BOLD-MRI was performed before and 12 months after RDN. Twenty-seven patients were imaged on 3 T and 19 on 1.5 T clinical MRI systems. RESULTS: Fifty-four patients were included, 46 patients (23 men, mean age 57 years) completed the study. Mean 24-h BP changed from 163(±20)/98(±14) mmHg to 154(±22)/92(±13) mmHg (p = 0.001 and p < 0.001). eGFR did not change after RDN [77(±18) vs. 79(±20) mL/min/1.73 m(2); p = 0.13]. RDN did not affect renal oxygenation [1.5 T: cortical R2*: 12.5(±0.9) vs. 12.5(±0.9), p = 0.94; medullary R2*: 19.6(±1.7) vs. 19.3(1.4), p = 0.40; 3 T: cortical R2*: 18.1(±0.8) vs. 17.8(±1.2), p = 0.47; medullary R2*: 27.4(±1.9) vs. 26.7(±1.8), p = 0.19]. CONCLUSION: The current study shows that RDN does not lead to changes in renal oxygenation 1 year after RDN as determined by BOLD-MRI. KEY POINTS: • Renal denervation significantly decreased ambulatory blood pressure. • Renal denervation did not change renal oxygenation as determined by BOLD-MRI. • Absence of a change in renal oxygenation might be explained by autoregulation.

Renal denervation for the treatment of hypertension: the Dutch consensus.

Since 2010, renal denervation (RDN) is being performed in the Netherlands. To make sure RDN is implemented with care and caution in the Netherlands, a multidisciplinary Working Group has been set up by the Dutch Society of Cardiology (NVVC). The main aim of this Working Group was to establish a consensus document that can be used as a guide for implementation of RDN in the Netherlands. This consensus document was prepared in consultation with the Dutch Association of Internal Medicine (NIV) and the Dutch Society of Radiology (NVVR).

The effect of percutaneous renal denervation on muscle sympathetic nerve activity in hypertensive patients.

OBJECTIVE: The rationale of percutaneous renal denervation (RDN) is based on extensive studies suggesting that renal nerves contribute to hypertension and that they comprise a sensible treatment target. Muscle sympathetic nerve activity (MSNA) is considered to be one of the few reliable methods to quantify central sympathetic activity. The aim of this current study is to determine the effect of RDN on MSNA in a standardized fashion. METHODS: MSNA was determined in 13 patients before and 6months after RDN. Anti-hypertensive medication was stopped before MSNA. If cessation of medication was considered unsafe, a patient was instructed to use the exact same medication on both occasions. RESULTS: Ten sets of MSNA recordings were of good quality for analysis. Mean age was 57 ± 3 years and mean eGFR was 85 ± 18 mL/min/1.73 m(2). MSNA was determined twice during a medication free interval in 5 patients; 1 patient used the exact same medication twice, and 4 patients used different drugs. Mean BP changed from 206 ± 7 over 116 ± 4 mmHg, to 186 ± 6 over 106 ± 3 mmHg, 6 months after RDN (p=0.06 for systolic BP, p=0.04 for diastolic BP). Mean resting heart rate did not change (p=0.44). MSNA did not change after RDN: 37 ± 4 bursts/min and 43 ± 4 bursts/min (p=0.11) at baseline and after RDN, respectively. In the 6 patients with standardized medication use during the MSNA sessions, results were comparable. CONCLUSIONS: Treatment with RDN did not result in a change in MSNA. Changes in BP did not correlate with changes in MSNA.

Nurse practitioners improve quality of care in chronic kidney disease: two-year results of a randomised study.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased cardiovascular risk. Here we evaluate whether strict implementation of guidelines aimed at multiple targets with the aid of nurse practitioners (NP) improves management in patients with CKD. METHODS: MASTER PLAN is a randomised controlled clinical trial, performed in nine Dutch hospitals. Patients with CKD (estimated glomerular filtration rate (eGFR) 20-70 ml÷min) were randomised to receive NP support (intervention group (IG)) or physician care (control group (CG)). Patients were followed for a median of five years. Presented data are an interim analysis on risk factor control at two-year follow-up. RESULTS: We included 788 patients (532 M, 256 F), (393 CG, 395 IG), mean (±SD ) age 59 (±13) years, eGFR 38 (±15) ml÷min÷1.73m(2), blood pressure (BP) 138 (±21)÷80 (±11) mmHg. At two years 698 patients (352 IG, 346 CG) could be analysed. IG as compared with CG had lower systolic (133 vs 135 mmHg; p= 0.04) and diastolic BP (77 vs 80 mmHg; p=0.007), LDL cholesterol (2.30 vs 2.45 mmol(-l); p= 0.03), and increased use of ACE inhibitors, statins, aspirin and vitamin D. The intervention had no effect on smoking cessation, body weight, physical activity or sodium excretion. CONCLUSION: In both groups, risk factor management improved. However, changes in BP control, lipid management and medication use were more pronounced in IG than in CG. Lifestyle interventions were not effective. Coaching by NPs thus benefits everyday care of CKD patients. Whether these changes translate into improvement in clinical endpoints remains to be established.

Hospital specific factors affect quality of blood pressure treatment in chronic kidney disease.

BACKGROUND: Blood pressure (BP) is the most important modifiable risk factor for cardiovascular (CV) disease and progression of kidney dysfunction in patients with chronic kidney disease. Despite extensive antihypertensive treatment possibilities, adequate control is notoriously hard to achieve. Several determinants have been identified which affect BP control. In the current analysis we evaluated differences in achieved BP and achievement of the BP goal between hospitals and explored possible explanations. METHODS: At baseline, BP was measured in a supine position with an oscillometric device in 788 patients participating in the MASTER PLAN study. We also retrieved the last measured office BP from the patient records. Additional baseline characteristics were derived from the study database. Univariate and multivariate analyses were performed with general linear modelling using hospital as a random factor. RESULTS: In univariate analysis, hospital was a determinant of the level of systolic and diastolic BP at baseline. Adjustment for patient, kidney disease, treatment or hospital characteristics affected the relation. Yet, in a fully adjusted model, differences between centres persisted with a range of 15 mmHg for systolic BP and 11 mmHg for diastolic BP. CONCLUSION: Despite extensive adjustments, a clinically relevant, statistically significant difference between hospitals was found in standardised BP measurements at baseline of a randomised controlled study. We hypothesise that differences in the approach towards BP control exist at the physician level and that these explain the differences between hospitals.

Percutaneous renal denervation for the treatment of resistant essential hypertension; the first Dutch experience.

BACKGROUND: In a subpopulation of patients with essential hypertension, therapeutic targets are not met, despite the use of multiple types of medication. In this paper we describe our first experience with a novel percutaneous treatment modality using renal artery radiofrequency (RF) ablation. METHODS: Patients who were resistant to at least three types of antihypertensive medical therapy (office systolic blood pressure ≥ 160 mmHg; n = 9) or who did not tolerate medication (n = 2) were selected. Between July and November 2010, a total of 11 patients received percutaneous RF treatment. Patients were followed up for 1 month after treatment. Urine and blood samples were taken to evaluate the effects on renal function and neurohumeral factors. RESULTS: No periprocedural complications or adverse events during follow-up were noted. A reduction of mean office blood pressure was seen from 203/109 ± 32/19 mmHg at baseline to 178/97 ± 28/21 mmHg at 1 month follow-up (mean difference 25 ± 12 mmHg, p < 0.01). Also, we noted a significant decrease in aldosterone level (391 ± 210 pmol/L versus 250 ± 142 pmol/L; p = 0.03), while there was no decrease in plasma renin activity (190 ± 134 fmol/L/s versus 195 ± 163 fmol/L/s; p = 0.43). No change in renal function was noted. CONCLUSION: Catheter-based renal denervation seems an attractive novel minimally invasive treatment option in patients with resistant hypertension, with a low risk of serious adverse events.

Lower estimated glomerular filtration rate and higher albuminuria are associated with mortality and end-stage renal disease. A collaborative meta-analysis of kidney disease population cohorts.

We studied here the independent associations of estimated glomerular filtration rate (eGFR) and albuminuria with mortality and end-stage renal disease (ESRD) in individuals with chronic kidney disease (CKD). We performed a collaborative meta-analysis of 13 studies totaling 21,688 patients selected for CKD of diverse etiology. After adjustment for potential confounders and albuminuria, we found that a 15 ml/min per 1.73 m² lower eGFR below a threshold of 45 ml/min per 1.73 m² was significantly associated with mortality and ESRD (pooled hazard ratios (HRs) of 1.47 and 6.24, respectively). There was significant heterogeneity between studies for both HR estimates. After adjustment for risk factors and eGFR, an eightfold higher albumin- or protein-to-creatinine ratio was significantly associated with mortality (pooled HR 1.40) without evidence of significant heterogeneity and with ESRD (pooled HR 3.04), with significant heterogeneity between HR estimates. Lower eGFR and more severe albuminuria independently predict mortality and ESRD among individuals selected for CKD, with the associations stronger for ESRD than for mortality. Thus, these relationships are consistent with CKD stage classifications based on eGFR and suggest that albuminuria provides additional prognostic information among individuals with CKD.

Cryoplasty of the venous anastomosis for prevention of intimal hyperplasia in a validated porcine arteriovenous graft model.

OBJECTIVES: Cryoplasty combines conventional angioplasty - percutaneous transluminal angioplasty (PTA) - with cold thermal energy. In this animal study, we investigated if preventive cryoplasty could reduce intimal hyperplasia (IH) at the venous anastomosis. DESIGN: We investigated cryoplasty versus PTA of the venous anastomosis in a validated porcine, bilateral, arteriovenous graft model. ANIMALS AND METHODS: In 12 pigs, 24 expanded polytetrafluoroethylene (ePTFE) grafts were bilaterally inserted between the common carotid artery and internal jugular vein. Directly after surgery, one venous anastomosis was treated with cryoplasty at -10 degrees C, the contralateral anastomosis with conventional PTA. At 4 weeks, graft flow was measured, quantitative angiography was performed and grafts with adjacent vessels were excised for histological analysis. RESULTS: Due to a number of thromboses, data for paired analysis were available from eight pigs. Angiographic outflow vein diameter and graft blood flow were not different between treatment groups. Compared with the control group, IH at the venous anastomosis was reduced by 47% (P=0.21) and intima/media ratio was reduced by 45% (P=0.07) by cryoplasty. Effects were most profound in those animals that tended to develop most IH. CONCLUSION: Our results suggest that preventive cryoplasty of the venous anastomosis might help to reduce IH in those cases that develop most profound IH.

Clinical profile of eprosartan: a different angiotensin II receptor blocker.

Rationale. The goal of antihypertensive treatment is to reduce risk of cardiovascular morbidity and mortality. Apart from blood pressure lowering per se, also reducing the activities of the renin-angiotensin system and sympathetic nervous system appears to be important. Angiotensin II receptor blocker drugs (ARBs) have provided a useful class of anti-hypertensive drugs. Eprosartan is a relatively new ARB which is chemically distinct (non-biphenyl, non-tetrazole) from all other ARBs (biphenyl tetrazoles). An analysis has been made on available experimental and clinical data on eprosartan which not only is an effective and well tolerated antihypertensive agent, but also lowers the activities of the renin-angiotensin system and sympathetic nervous system. Experimental and pharmacokinetic studies on eprosartan have shown differences with the other ARBs. The distinct properties of this non-biphenyl, non-tetrazole ARB might be relevant in the effort to reduce cardiovascular risk, also beyond its blood pressure lowering capacity.

Implementation of a vascular access quality programme improves vascular access care.

INTRODUCTION: In the Netherlands an access quality improvement plan (QIP) was introduced by vascular access coordinators (VAC) with the aim to decrease vascular access-related complications by preemptive intervention of malfunctioning accesses. A vascular access QIP was established in 24 centres (46% of all Dutch facilities) and a structural multidisciplinary vascular access meeting was instituted. In these centres, including 2300 patients, a protocol for enhancement of fistula creation and access surveillance programme was implemented, with instruction of physicians and nurses, and rounds to discuss complications and evaluate vascular access interventions. The number and type of vascular access, permanent catheters, thrombosis rates and number of interventions were evaluated at the start and end of the study period. RESULTS: After the surveillance programme, the number of autogenous arterio-venous fistulas (AVFs) had increased significantly from 69 to 77% (P < 0.01), while the use of temporary subclavian vein catheters declined (34% vs 11%) (P < 0.01), with a substantially higher percentage of jugular vein catheters (from 23 to 35%). Interventional treatment of malfunctioning accesses by percutaneous transluminal angioplasty (PTA) (from 0.39 to 0.50 patient/year; P < 0.001)) and surgical revisions (from 0.06 to 0.12 per patient/year; P < 0.001) also increased. CONCLUSION: These data demonstrate that a vascular access QIP resulted in placement of more autogenous AVFs, increased number of PTAs and surgical interventions. These findings suggest that a vascular access care QIP is worthwhile to improve dialysis patients' care and access morbidity.