Hypertension In Hemodialysis Patients Research Articles

Pulmonary hypertension in hemodialysis patients: Prevalence and associated factors

Background and objectivePulmonary 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 methodsWe 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). ResultsPH 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=0.001), time on renal replacement therapy (p=0.04), the presence of systolic dysfunction (p=0.007), diastolic dysfunction (p=0.01), mitral valve disease (p=0.01) and double mitral and aortic disease (p=0.007). Volume overload was closely associated with PH, as demonstrated by the correlation between the SPAP and Nt-proBNP levels (p=0.001). ConclusionWe 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.

Renal denervation in a patient with Alport syndrome and rejected renal allograft

Renal denervation is a new intervention to treat resistant hypertension. By applying radiofrequency (RF) to renal arteries, sympathetic nerves in adventitia layer of vascular wall can be denervated. Sympathetic hyperactivity is an important contributory factor in hypertension of hemodialysis patients. Hyperactive sympathetic nervous system aggravates hypertension and it can cause complications like left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. Our report illustrates the use of renal denervation using conventional RF catheter for uncontrolled hypertension in a patient with Alport syndrome and rejected renal allograft. Progressive and sustained reduction of blood pressure was obtained post-procedure and at 24 months follow-up with antihypertensives decreased from 6 to 2 per day, thereby demonstrating the safety, feasibility, and efficacy of the procedure. There are some reports available on the usefulness of this technique in hemodialysis patients; however, there are no studies of renal denervation in patients with Alport syndrome and failed allograft situation.

Isonatric Dialysis Biofeedback in Hemodiafiltration with Online Regeneration of Ultrafiltrate in Hypertensive Hemodialysis Patients: A Randomized Controlled Study

Dialysis biofeedback in hemodiafiltration with online regeneration of ultrafiltrate (HFR) could help to improve arterial hypertension. We evaluated the impact of isonatric HFR (HFR-iso) on hypertension control compared to conventional HFR. Forty-seven hemodialysis patients were included and randomized (ratio 2/1) HFR-iso versus HFR during 24 dialysis sessions. In the HFR-iso group (32 patients, 768 dialysis sessions), the predialytic systolic blood pressure (BP) decreased from S1 to S24 of 9 ± 20 mm Hg and increased of 5 ± 24 mm Hg in the HFR group (15 patients, 360 dialysis sessions), variation that differed between the 2 groups (ΔS1-S24, p = 0.035; interaction group*time, p = 0.012). The diastolic BP (HFR-iso -3 ± 14 mm Hg vs. HFR 5 ± 13 mm Hg; p = 0.088), the DDD of antihypertensive treatment and the dry weight did not vary significantly during the study. Number of sessions complicated by symptomatic hypotension was similar in the 2 groups. HFR-iso improved BP control without increasing dialysis hypotension episodes. Short Summary: In this multicenter, open-label, controlled, randomized study, we evaluated the impact of dialysis biofeedback in HFR on arterial hypertension compared to conventional HFR. We observed that HFR-iso improved arterial BP control without increasing dialysis hypotension episodes.

Increasing Dialysis Sodium Removal on Arterial Stiffness and Left Ventricular Hypertrophy in Hemodialysis Patients

The aim of the present study was to examine the effects of a mild increase in dialysis sodium removal on cardiovascular system in hypertensive hemodialysis (HD) patients. Sixty four HD patients with pre-HD plasma sodium level higher than 138mmol/l, were randomly assigned into 2 groups. The dialysate sodium was reduced from 138mmol/l to 136mmol/l in the intervention group, while remained at 138mmol/l in the control group. During the study course, home systolic blood pressure (BP) target of 140mmHg was used in all patients, and bioimpedance measurements to guide ultrafiltration were performed monthly. 44-hour ambulatory BP, aortic pulse wave velocity (PWV), left ventricular mass index (LVMI), pre-HD plasma sodium concentration, interdialytic weight gain, and dietary sodium intake, were measured. Better BP control was achieved by 2 groups, with no significant differences. However, less annual averages of antihypertensives were used in the intervention group. The PWV values significantly decreased from 11.8±2.4 to 10.9±2.6m/s in the intervention group (P<0.001), and from 11.6±2.5 to 11.1±2.2m/s in the control group (P=0.012). LVMI regressed from 151±19 to 139±16 g/m2 (P<0.001) in the intervention group only. In addition, values for interdialytic weight gain and pre-HD plasma sodium decreased in the intervention group only. There were no significant differences in annual averages of dietary sodium intake and the frequency of adverse events between the 2 groups. Increasing dialysis sodium removal was associated with improvements in arterial stiffness, left ventricular hypertrophy, and better BP control in hypertensive HD patients.

Relative Importance of Aortic Stiffness and Volume as Predictors of Treatment-Induced Improvement in Left Ventricular Mass Index in Dialysis.

This study aimed to explore the relative contribution of aortic stiffness and volume in treatment-induced change of left ventricular mass in dialysis. Hypertension in Hemodialysis Patients Treated with Atenolol or Lisinopril trial compared the effect of lisinopril versus atenolol in reducing left ventricular mass index; 179 patients with echo measurements of aortic pulse wave velocity and left ventricular mass at baseline were included. In unadjusted analysis, overall reductions of 26.24 g/m2 (95% CI: -49.20, -3.29) and 35.67 g/m2 (95% CI: -63.70, -7.64) in left ventricular mass index were noted from baseline to 6 and 12 months respectively. Volume control emerged as an important determinant of regression of left ventricular mass index due to the following reasons: (i) additional control for change in ambulatory systolic blood pressure mitigated the reduction in left ventricular mass index in the statistical model above [6-month visit: -18.6 g/m2 (95% CI: -43.7, 6.5); 12-month visit: -22.1 g/m2 (95% CI: -52.2, 8.0)] (ii) regression of left ventricular hypertrophy was primarily due to reduction in left ventricular chamber and not wall thickness and (iii) adjustment for inferior vena cava diameter (as a proxy for volume) removed the effect of time on left ventricular mass index reduction [6-month visit: -6.6 g/m2 (95% CI: (-41.6, 28.4); 12-month visit: 0.6 g/m2 (95% CI: -39.5, 40.7)]. In contrast, aortic pulse wave velocity was neither a determinant of baseline left ventricular mass index nor predictor of its reduction. Among dialysis patients, ambulatory systolic pressure, a proxy for volume expansion, but not aortic stiffness is more important predictor of reduction in left ventricular mass index. Improving blood pressure control via adequate volume management appears as an effective strategy to improve left ventricular hypertrophy in dialysis.

Abstract P632: The Blood Pressure in Dialysis (BID) Pilot Study

Background: The optimal blood pressure (BP) target for hypertensive hemodialysis (HD) patients is unknown. Current KDOQI guidelines have been extrapolated from data in the general population. The BID pilot, funded by NIDDK and DCI, is the first trial to randomize hypertensive HD patients to intensive (110-140 mm Hg) vs. usual (155-165 mm Hg) control of systolic blood pressure (SBP). The study’s goal is to assess the feasibility of conducting a full-scale trial. Methods: BID consortium consists of 5 clinical centers, a cardiac MRI reading center and a data coordinating center. Standardized predialysis SBP, measured in the dialysis unit in accord with AHA recommendations (SDUSBP), guide therapy. To be eligible for randomization patients needed a 2-week running mean SDUSBP ≥ 155 mm Hg. Home BP measurements (HBPM) are obtained twice on the day after the midweek dialysis. Ambulatory Blood Pressure Monitoring (ABPM) during a 44h interdialytic period is obtained quarterly. We compared SDUSBP, HBPM and ABPM. Results: We enrolled 281 and randomized 126 participants. Major reasons for drop out during the baseline period were 2-week mean SDUSBP &lt; 155 mm Hg (40.6%), no cardiac MRI (13.0%) and perception of protocol as burdensome (11.2%). Adherence with prescribed SDUSBP was satisfactory. The percent of patients with ≥ 4, ≥ 8 and ≥12 SBP per month were 96, 88 and 57% in month 1 and 78, 68 and 37% in month 12. In a constant cohort of participants followed ≥ 330 days 2-week mean SDUSBP were 144 ± 17.4 and 156 ± 15.2 mm Hg in the intensive and usual arms, respectively. Major reasons that participants in the intensive arm did not achieve target SBP included large interdialytic weight gain (27.2%), non-adherence with medications or dialysis prescription (40.9%), and intradialytic hypotension (31.9%). Differences between the SDUSBP and both HBPM and ABPM were often ≥ 10 mm Hg. Optimal control of BP requires measurements in and out of the dialysis unit. Rates of adverse events were similar to those in other NIDDK funded ESRD studies. Conclusion: The difference in BP between arms was achieved and maintained throughout the study. It is feasible to conduct a full-scale clinical trial of intensive vs. usual treatment of hypertension in HD patients.

PP.LB02.27

Objective: Renalase is an enzyme that circulates in the blood and modulates the cardiac function, sympathetic tone and systemic blood pressure. It can be synthesized in the kidneys, liver and cardiomyocytes. The active enzyme degrades circulating catecholamines, causing a significant fall in blood pressure. Changes in renalase concentration in hemodialysis patients may explain the frequent occurrence of hypertension among patients with end-stage kidney disease. The aim of this study was to asses’ serum renalase levels in hemodyalisis patients and apparently healthy subjects, and association of renalase and blood pressure in patients group. Design and method: 160 subjects were recruited in the study: 120 with end-stage renal disease, divided into two groups, according to their blood pressures (normotensive and hypertensive), and 40 apparently healthy individuals matched in age and sex. Blood pressure was measured before and after a hemodialysis session. The target values, according to ESH/ESC guidelines, were lower than 140/90 mmHg before, and 130/90 mmHg after hemodialysis. The blood for the estimating serum renalase concentration was taken before dialysis. Enzyme-linked immunosorbent assay (ELISA) kit with monoclonal antibody specific to renalase, was used. Results: Mean serum renalase levels in normotensive as well as hypertensive hemodialysis patients were significantly higher compared to control group {89.32 (45.77–170.22) and 42.7 (32.79–63.35) μg/ml, respectively; p < 0.0005}. No significant difference of renalase levels among normotensive and hypertensive patients was noted {64.04 (40.76–173.84) and 91.86 (56.77–149.75.35)μg/ml; (p > 0.05)}. There was a highly significant difference between systolic and diastolic pressure measured before and after the dialysis in normotensive and hypertensive groups of patients (p < 0.0005). It was noted that there is a significant, negatively directed association between patients’ age at the beginning of dialysis and the duration of hemodialysis. Also, the correlation between blood pressure and renalase activity among normotensive and hypertensive hemodialysis patients was not shown (p > 0.05). Conclusions: Further studies are needed to define the role of renalase and its complex pathophysiological link with blood pressure regulation, kidney function and sympathetic tone. Renalase may become a new therapeutic target that leads to a better prognosis for patients with end-stage kidney disease.

Ambulatory Blood Pressure Monitoring Profile of Chronic Hemodialysis Patient in Hemodialysis Unit MRCCC Hospital Siloam Semanggi

Background: The leading cause of morbidity and mortality in hemodyalisis patients is Cardiovascular disease. Hypertension is the single most important factor for the development of cardiovascular complications. Diagnosing hypertension in hemodyalisis patients is not easy, it's because fluid retension effect, office hypertension, and ultrafiltration after hemodyalisis session. Gold standard for diagnosing hypertension in hemodialysis patient is interdialytic blood pressure measurment with Ambulatory Blood Pressure Monitoring (ABPM). Objective: To determine the ABPM profile of Chronic Hemodialysis Patient In MRCCC(Mochtar Riady Comprehensive Cancer Center) Siloam Hospital Hemodialysis Unit. Method: A cross sectional study design was conducted in five adult patients with chronic hemodialysis. Patients who fulfilled inclusion criteria were recruited for measuring their blood pressure using 24 hours ABPM. Result: Mean age of our patient is 54.8 years, 60% were men and 40% were women. Sistolic blood pressure from ABPM result is 147 mmHg (24.83), and diastolic blood pressure from ABPM result is 85 mmHg (13.72). The prevalence of hypertension in this study among chronic hemodialysis patient in MRCCC Siloam Hospital Hemodialysis Unit is 80%. From 5 of our patients 2(40%) have DM, 3(60%) without DM. We also found that 1(20%) patients have dipping pattern during night and 4(80%) patients without dipping pattern during night. In two of our diabetic patients all of them (100%) without dipping pattern during night. Conclusion: Hypertension is frequent in chronic hemodialysis patient, in diabetic patients non-dipping pattern more frequently seen, hypertension more accurately diagnose by ABPM in patient with chronic hemodialysis.

Moderator's view: Ambulatory blood pressure monitoring and home blood pressure for the prognosis, diagnosis and treatment of hypertension in dialysis patients.

Major health agencies now recommend the systematic application of ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension. Given the exceedingly high prevalence of nocturnal hypertension, masked and white coat hypertension and the overt inadequacy of peridialysis (pre-, intra- and post-dialysis) BP measurements, more extensive application of ABPM for the diagnosis of hypertension in dialysis patients would appear logical. In a recent survey performed in NDT Educational, organizational problems and/or cognitive resistance emerged as important factors hindering more extensive application of ABPM and home BP by nephrologists. External validation of observations made in landmark studies in a single institution about hypertension subcategorization by ABPM is urgently needed. Furthermore, apparent cognitive resistance by nephrologists may be justified by the fact that these techniques have been insufficiently tested in the dialysis population for applicability in everyday clinical practice, tolerability, organizational impact and cost-effectiveness. We should be more resolute in abandoning peridialysis measurements for diagnosing and treating hypertension in haemodialysis patients. Home BP is a formidable educational instrument for patient empowerment and self-care, and evidence exists that this technique is superior to peridialysis values to better hypertension control as defined on the basis of ABPM. We should strive to promote more extensive application of home BP monitoring to diagnose and manage hypertension in haemodialysis patients. ABPM with novel, user friendly and better tolerated techniques is to be awaited in the near future.

Aortic Stiffness, Ambulatory Blood Pressure, and Predictors of Response to Antihypertensive Therapy in Hemodialysis

Arterial stiffness is associated with elevated blood pressure (BP), but it is unclear whether it also makes hypertension more resistant to treatment. Among hypertensive dialysis patients, this study investigated whether aortic stiffness determines ambulatory BP and predicts its improvement with therapy. Post hoc analysis of the Hypertension in Hemodialysis Patients Treated With Atenolol or Lisinopril (HDPAL) trial. 179 hypertensive hemodialysis patients with echocardiographic left ventricular hypertrophy. Baseline aortic pulse wave velocity (PWV). Baseline and treatment-induced change in 44-hour ambulatory BP at 3, 6, and 12 months. Aortic PWV was assessed with an echocardiographic-Doppler technique (ACUSON Cypress, Siemens Medical), and 44-hour interdialytic ambulatory BP monitoring was performed with a Spacelabs 90207 monitor. Mean baseline aortic PWV was 7.6±2.7 (SD) m/s. Overall treatment-induced changes in ambulatory systolic BP (SBP) were -15.6±20.4, -18.9±22.5, and -20.0±19.7 mmHg at 3, 6, and 12 months. Changes in SBP were no different among tertiles of baseline PWV. Aortic PWV was associated directly with baseline ambulatory SBP and pulse pressure (PP) and inversely with diastolic BP (DBP). After adjustment for several cardiovascular risk factors, each 1-m/s higher PWV was associated with 1.34-mm Hg higher baseline SBP (β=1.34±0.46; P=0.004) and 1.02-mm Hg higher PP (β=1.02±0.33; P=0.002), whereas the association with DBP was no longer significant. Baseline PWV did not predict treatment-induced changes in SBP (Wald test, P=0.3) and DBP (Wald test, P=0.7), but was a predictor of an overall improvement in PP during follow-up (Wald test, P=0.03). Observational design; predominantly black patients were studied. Because aortic PWV is not a predictor of treatment-induced change in ambulatory BP among hypertensive dialysis patients, it indicates that among these patients, hypertension can be controlled successfully regardless of aortic stiffness.

Come gestire l'ipertensione arteriosa in emodialisi?

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Dealing with hypertension in hemodialysis patients

Hypertension is a well-known cardiovascular risk factor also for hemodialysis patients. Despite being common in this patient population, hypertension is often difficult to diagnose and poorly controlled.Blood pressure variability (BPV) is a new parameter and a predictor of poor outcomes in the general population. A recent observational study in over 11,000 hemodialysis patients showed that high BPV is associated with an increased risk of all-cause mortality, cardiovascular mortality, and first cardiovascular event. High BPV is associated with female gender, black race, obesity, diabetes and/or cardiovascular disease, hemoglobin levels less than 10 g/dL, high calcium-phosphate product, and use of three or more anti-hypertensive drugs.Today, the management of hypertension in hemodialysis patients requires more and more care, not only from the diagnostic point of view, but also in prognosis and therapy, especially regarding the non-pharmacological approach.

Nephrology Crosswords: Hemodialysis

ACROSS 1 These dialysis membranes clear 10–20 kDa solutes and have a pore size of 3–6 nm. (8) 3 Low concentrations of potassium and ____ have been associated with sudden cardiac death in dialysis patients. (7) 8 This alternate form of anticoagulation on hemodialysis has been speculated to worsen secondary hyperparathyroidism. (7) 10 This large randomized trial showed that statins had no reduction in either overall or cardiovascular mortality in patients with chronic kidney disease who reached end-stage renal disease. (5) 12 In the Frequent Hemodialysis Network trial that looked at in-center hemodialysis six times per week versus three times per week, the group that had more frequent dialysis had more ___ related complications. (6) 13 After initiating dialysis, the mortality is the highest in the first ___ weeks. (3) 14 This uremic toxin is toxic to endothelium and leads to vasculogenesis. (12) DOWN 1 ____ impairs the absorption and recycling of iron and inhibits the proliferation of erythroid progenitor cells. (8) 2 This landmark trial showed that patients undergoing hemodialysis thrice weekly appear to have no major benefit from a higher dialysis dose than that recommended by current U.S. guidelines or from the use of a high-flux membrane. (4) 4 Frequency ____ of dialysis and membrane type are important considerations for removal of low-molecular-weight uremic toxins. (6) 5 Low ____ concentrations have been shown to be associated with symptomatic or asymptomatic intradialytic hypotension. (9) 6 Based on the European Best Practice Guidelines, the minimum frequency and dose of dialysis is ___ hours per treatment three times per week for most patients. (4) 7 Relative plasma volume may be a useful technique to assess __ _____ among hypertensive hemodialysis patients. (9) 9 The most common cause of end-stage kidney disease in the United States. (8) 11 Dialysate ____ is a potential culprit substance that leads to intradialytic hypotension. (7) 12 This uremic protein-bound toxin reduces nitric oxide synthesis and provokes an increase in systemic vascular resistance and hypertension. (Abbrv) (4) http://www.kidney-international.org m a k e y o u r d i a g n o s i s

Bilateral nephrectomy for uncontrolled hypertension in hemodialysis patient: A forgotten option?

Resistant arterial hypertension in chronic hemodialysis patients is still a therapeutical challenge despite the development of modern antihypertensive drugs and dialysis procedures. Bilateral nephrectomy seems to be a forgotten option, although it has given good results. We present a case of a 39-year-old female chronic hemodialysis patient, in whom the problem of uncontrolled renal parenchymal hypertension remained despite multiple drug therapy and the ultrafiltration intensification. The problem was solved by bilateral nephrectomy. We discuss the role of bilateral nephrectomy for arterial hypertension control in chronic hemodialysis patients and the surgical and non-surgical options of nephrectomy.

Impact of renal artery stent implantation on hypertension in patients with hemodialysis.

The benefit from renal artery stent implantation to treat atherosclerotic renal artery stenosis (ARAS) is not well understood in hemodialysis patients. We sought to evaluate the effects of renal artery stenting on hypertension of hemodialysis patients. Renal artery stent implantation was successfully performed on eight hypertensive hemodialysis patients with ARAS (mean ± SD, 66 ± 10 years; men 6, women 2). Blood pressure was measured by automated oscillometric recordings just before hemodialysis. Mean values of the blood pressure, measured 12 times a month, were used for blood pressure analysis. Values of systolic blood pressure decreased at 6 months after renal artery stent implantation (162.6 ± 29.7 to 121.1 ± 23.3 mm Hg, p = 0.0015). Values of diastolic blood pressure also decreased from 77.6 ± 13.6 to 65.6 ± 7.2 mm Hg (p = 0.02). Renal artery stent implantation for ARAS had a beneficial effect on hypertension in hemodialysis patients.

Troponin I and NT-proBNP and the Association of Systolic Blood Pressure With Outcomes in Incident Hemodialysis Patients: The Choices for Healthy Outcomes in Caring for ESRD (CHOICE) Study

There is uncertainty regarding treatment of hypertension in hemodialysis patients due to the observed J-shaped association between blood pressure (BP) and death. We hypothesized that this association reflects confounding by cardiovascular disease (CVD) and that stratification by CVD biomarkers, cardiac troponin I (cTnI) and N-terminal fragment of prohormone brain natriuretic peptide (NT-proBNP), might change this association. National prospective cohort study. 446 incident hemodialysis patients. Predialysis systolic BP. Mortality (all-cause and CVD) and first CVD event assessed using Cox regression adjusted for demographics, comorbid conditions, and clinical factors. Participants with cTnI level ≥0.1 ng/mL or NT-proBNP level ≥9,252 pg/mL were classified as the high-biomarker group; remaining participants were included in the low-biomarker group. Participants in the high-biomarker group (n=138 [31%]) were older (61 vs. 57 years) and had a higher prevalence of CVD (67% vs. 23%), but similar baseline BPs (152 vs. 153 mm Hg). There were 323 deaths (143 from CVD) and 271 CVD events. The high-biomarker group had a higher risk of mortality than the low-biomarker group (HR, 1.75; 95% CI, 1.37-2.24). The association between BP and outcomes differed between the 2 biomarker groups (P for interaction=0.01, 0.2, and 0.07 for all-cause mortality, CVD mortality, and first CVD event, respectively). In the low-biomarker group, BP was associated with greater risk of outcomes: HR per 10 mm Hg higher BP was 1.07 (95% CI, 1.01-1.14), 1.10 (95% CI, 0.96-1.25), and 1.04 (95% CI, 0.96-1.13) for all-cause mortality, CVD mortality, and first CVD event, respectively. Importantly, lower BP was not associated with increased risk of outcomes in stratified models, including for those in high biomarker group. BP measurements not standardized. The observed J-shaped association between BP and outcomes in hemodialysis patients is due to confounding by subclinical CVD. A stratification approach based on cTnI and NT-proBNP levels has the potential to inform BP treatment in hemodialysis patients.

Cardiovascular protection by -blockade in hypertensive haemodialysis patients: the Hypertension in Haemodialysis Patients Treated With Atenolol or Lisinopril (HDPAL) trial

Cardiovascular protection by -blockade in hypertensive haemodialysis patients: the Hypertension in Haemodialysis Patients Treated With Atenolol or Lisinopril (HDPAL) trial

Dialysate Sodium Prescription and Blood Pressure in Hemodialysis Patients

Diffusive sodium removal has been recommended to control hypertension in hemodialysis patients. Recent evidence on hospitalizations and mortality, however, challenged the benefit of lower dialysate sodium prescriptions and ignited a debate in the dialysis community. We therefore studied the relationship between dialysate sodium and blood pressure over the longer term. We used multiply adjusted linear mixed models to estimate the association between dialysate sodium and predialysis systolic blood pressure (SBP) as well as change in SBP (delta SBP; postdialysis minus predialysis) in 23,962 patients from the international Dialysis Outcomes and Practice Patterns Study. We found that 43% of hemodialysis facilities had variable (individualized) dialysate sodium prescriptions (125-155 mEq/L), whereas 57% had uniform dialysate sodium prescriptions (135-145 mEq/L) for ≥90% patients. Between-group comparisons of these 2 facility types suggested that dialysate sodium, when variably prescribed, might have been used to modify predialysis SBP (P interaction = 0.01) and perhaps delta SBP levels (P interaction = 0.08). Within facilities not prone to indication bias, because dialysate sodium was not variable, higher uniform dialysate sodium (per 2 mEq/L) was associated with slightly higher SBP (+0.9 mm Hg, 95% confidence interval (CI) = 0.1-1.6 among all patients; +1.7 mm Hg, 95% CI = 0.1-3.2 among patients not treated with blood pressure medication) and no increase in delta SBP. Patients assigned to hemodialysis facilities with uniformly higher dialysate sodium do not have markedly higher predialysis SBP, providing rather limited support for lowering dialysate sodium to control hypertension, particularly in view of hospitalization and mortality risks associated with lower dialysate sodium.

Cardiovascular protection by -blockade in hypertensive haemodialysis patients: the Hypertension in Haemodialysis Patients Treated With Atenolol or Lisinopril (HDPAL) trial

In the pioneer years of chronic haemodialysis (HD), hypertension was recognized as the main undisputable cause of death in end-stage kidney disease (ESKD) patients [1]. Nearly a halfcentury later, sparse data in various countries indicate that control of hypertension in the HD population still remains a major unmet clinical need worldwide. In the USA, the prevalence of hypertension exceeds 80% [2], in Great Britain it is about 50% [3] and in Italy about 70% [4]. Progress in this area has been in part hindered by the ‘reverse epidemiology’ scenario that characterizes the HD population. Uncertainty about blood pressure (BP) targets and methods of measurement is such that the Renal Association guidelines cautiously state that ‘It would be sensible to avoid sustained BP extremes and, in order to try to provide some guidance, we suggest that systolic blood pressure during the interdialytic period on HD and for peritoneal dialysis (PD) patients should not regularly exceed >160 mmHg’ [3]. Low pre-dialysis BP rather than high BP is associated with death risk. Furthermore, in sharp contrast to a large meta-analysis in individuals in the general population without a background of cardiovascular events [5], the pre-dialysis relationship between BP and death risk in end-stage kidney disease (ESKD) is definitely non-linear [6]. However, peri-dialytic BP measurements are inherently inadequate metrics of the BP burden because measurements before dialysis overestimate the underlying average BP while post-dialysis BP underestimates the same parameter. In studies applying ambulatory blood pressure monitoring (ABPM) in the HD population without severe heart failure, the link between BP and clinical outcomes is comparable with that registered in the general population with the same technique [7]. Indeed, high average ambulatory systolic pressure [8] and nocturnal systolic hypertension [9] during the dialysis intervals are strong death predictors in HD patients. Notwithstanding the public health relevance of the problem and the peculiar risk profile of the ESKD population, the number of randomized, controlled trials (RCTs) testing antihypertensive drugs in dialysis patients is very limited indeed. A meta-analysis performed in 2009 [10] identified only eight randomized trials. Of these, one was performed in patients on peritoneal dialysis, two dealt with normotensive or hypotensive patients affected by left ventricular systolic dysfunction or heart failure and another trial (FOSIDIAL) selected patients with left ventricular hypertrophy (LVH), independent of BP [11]. After this meta-analysis, the OCTOPUS trial was published [12]. Thus, we have just four relatively small RCTs specifically focusing on drug treatment of hypertension in HD patients without severe heart failure (NYHA class III or IV) (Fig. 1). Of these trials, one tested a calcium antagonist (amlodipine) [13] and three various angiotensin II receptor blockers (ARBs): candesartan in the first [14]; candesartan, losartan or valsartan in the second [15] and olmesartan in the third [12]). In trials testing ARBs, the antihypertensive effect of these drugs was comparable with that achieved by other drugs. Nonetheless, of these three trials, two documented a reduction in the risk of cardiovascular events (−47% [3] and −71% [4]). If we consider also the FOSIDIAL trial where about half of the patients were hypertensive, the combined analysis (random-effects) of trials based on ARBs and angiotensin-converting enzyme inhibitors (ACEi) shows a 31% risk reduction [RR: 0.69, 95% confidence interval (95% CI) 0.45–1.05, P = 0.086], which just fails to achieve statistical significance. Because BP in patients randomized to ACEi or ARBs in these trials was almost identical to that in patients randomized to other drugs, the apparent benefit of ACEi or ARBS appears attributable to the interference with angiotensin II effects on the cardiovascular system beyond vasoconstriction. These results are similar to those of a recent meta-analysis reporting a substantial, BP-independent, benefit of ACEi and ARBs in over 100 000 high-risk patients without heart failure [16] most of whom were hypertensive. IN F O C U S

Hypertension in hemodialysis patients: an opinion-based update.

Hypertension is highly prevalent in hemodialysis patients but its management remains a matter of debate. In this review, we discuss the observational studies on the association of blood pressure with outcomes, measurement of blood pressure in hemodialysis patients and present an opinion-based approach to treating hypertension.