Systolic blood pressure and mortality in prevalent haemodialysis patients in the HEMO study

Different time points, different blood pressures: complexity of blood pressure measurement in hemodialysis patients

OBJECTIVE

We used our established database to investigate predialysis blood pressure (BP) measurements at different time points.

METHODS

Our study period spanned from 1 January 2019 to 31 December 2019. The different time points included: the long interdialytic interval versus the short interdialytic interval; different hemodialysis shifts. Multiple linear regression was used to explore the association between BP measurements and different time points.

RESULTS

A total of 37 081 cases of hemodialysis therapies were included. After a long interdialytic interval, predialysis SBP and DBP were significantly elevated. Predialysis BP was 147.72/86.73 mmHg on Monday and 148.26/86.52 mmHg on Tuesday, respectively. Both predialysis SBP and DBP were higher in the a.m. shift. The mean BP in the a.m. and p.m. shifts were 147.56/87 mmHg and 144.83/84.64 mmHg, respectively. In both diabetic nephropathy and non-diabetic nephropathy patients, higher SBP measurements after a long interdialytic interval were observed; however, in diabetic nephropathy patients, we did not find significant differences in DBP among different dates. In diabetic nephropathy and non-diabetic nephropathy patients, we observed that the effect of different shifts on BP was similar. In Monday, Wednesday and Friday subgroups, the long interdialytic interval was also associated with BP; however, in Tuesday, Thursday and Saturday subgroups, different shifts but not the long interdialytic interval was associated with BP.

CONCLUSION

The long interdialytic interval and different hemodialysis shifts have a significant effect on predialysis BP in patients with hemodialysis. When interpreting BP in patients with hemodialysis, different time points is a confounder.

Interdialytic Blood Pressure and Risk of Cardiovascular Events and Death in Hemodialysis Patients

INTRODUCTION

Normal (120-140 mm Hg) systolic peridialysis blood pressure (BP) is associated with higher mortality in hemodialysis (HD) patients.

AIM

We explored the relationship between hypertension and BP on outcomes using data collected at the interdialytic period.

METHODS

This was a single-center observational cohort study with 2672 HD patients. BP was determined at inception, in mid-week, between 2 consecutive dialysis sessions. Hypertension was defined as systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg. Endpoints were major CV events and all-cause mortality.

RESULTS

During a median follow-up of 31 months, 761 patients (28%) experienced CV events and 1181 (44%) died. Hypertensive patients had lower survival free of CV than normotensive patients (P = 0.031). No difference occurred in the incidence of death between groups. Compared with the reference category of SBP ≥ 171 mmHg, the incidence of cardiovascular events was reduced in patients with SBP 101-110 (HR 0.647, 95% CI 0.455 to 0.920), 111-120 (HR 0.663, 95%CI 0.492 to 0.894), 121-130 (HR 0.747, 95%CI 0.569 to 0.981), and 131-140 (HR 0.757, 95%CI 0.596 to 0.962). On multivariate analysis, systolic and diastolic BP were not independent predictors of CV events or death. Normal interdialytic BP was not associated with mortality or CV events, and hypertension predicted an increased probability of CV complications.

CONCLUSIONS

Interdialytic BP may be preferred to guide treatment decisions, and HD patients should be treated according to guidelines for the general population until specific BP targets for this population are identified.

Timing of Antihypertensive Medications on Key Outcomes in Hemodialysis: A Cluster Randomized Trial

Background

We conducted this study to examine the effect of taking versus holding BP medications before hemodialysis on intradialytic hypotension (IDH).

Methods

In this cluster randomized trial, each dialysis unit was randomly designated as TAKE or HOLD units. Participants within a TAKE unit were instructed to take all BP medications as prescribed, whereas participants within a HOLD unit were instructed to hold medications dosed more than once daily before hemodialysis. The intervention lasted for 4 weeks. We hypothesized that TAKE would be noninferior to HOLD on the primary outcome of asymptomatic IDH, defined as ≥30% of sessions with nadir systolic BP <90 mm Hg and on the following secondary outcomes: uncontrolled hypertension (predialysis systolic BP >160 mm Hg), failure to achieve dry weight, and shortened dialysis sessions.

Results

We randomized 10 dialysis units in a 1:1 ratio to TAKE or HOLD, which included 65 participants in TAKE and 66 participants in HOLD. We did not show that TAKE was noninferior to HOLD for the primary IDH outcome (mean unadjusted difference of 8%; 95% CI, -3% to 19%). TAKE was superior to HOLD for the outcome of uncontrolled hypertension (mean unadjusted difference of -15%, 95% CI, -28% to -1%). TAKE was noninferior to HOLD for the outcomes of failure to achieve dry weight and shortened dialysis sessions.

Conclusions

In this cluster randomized trial that randomized patients to either taking or holding BP medications before hemodialysis, a strategy of taking BP medications dosed more than once daily was not noninferior to holding BP medications for the primary outcome of IDH, but did reduce the occurrence of uncontrolled hypertension. Whether any potential benefit of holding BP medications on reducing IDH is offset by any potential harm related to higher predialysis BP remains to be seen.

Association of blood pressure with mortality in hemodialysis patients with a tunneled cuffed catheter: A single-center observational study

The use of tunneled cuffed catheters (TCCs) for permanent blood access is increasing as the hemodialysis population ages. However, the higher mortality and complication rates associated with their use have been significant concerns. This single-center observational cohort study aimed to investigate clinical factors affecting mortality and complications in Japanese hemodialysis patients with a TCC.We enrolled 64 consecutive patients receiving hemodialysis through a TCC between 2012 and 2019. The primary outcome was all-cause mortality and the secondary outcome was the incidence of catheter-related complications at 2 years. Cox proportional hazards models were used to examine variables associated with these outcomes.At 2 years, death from any cause and catheter-related complications occurred in 27/64 (42%) and 23/64 (36%) patients, respectively. There were 14 bacteremia events, 7 catheter obstructions, and 8 instances of restricted blood flow. Multivariate analysis showed that systolic blood pressure (SBP) < 100 mm Hg at the time of catheter insertion was associated with higher all-cause mortality (hazard ratio, 2.59; 95% confidence interval, 1.05-6.41) and catheter-related complications (hazard ratio, 2.57; 95% confidence interval, 1.52-22.2). The Kaplan-Meier analyses also showed that patients with SBP <100 mm Hg had higher mortality (P = .001) and a higher incidence of catheter-related complications (P = .0068).SBP <100 mm Hg at the time of catheter insertion is associated with mortality and catheter-related complications in hemodialysis patients using a TCC. Further multi-center studies are required to validate our results.

The obesity paradox: A further consideration in dialysis patients

Several epidemiological cohorts have demonstrated that higher body mass index (BMI) is associated with lower mortality risk among patients receiving hemodialysis. However, BMI may be an inaccurate indicator of nutritional status among dialysis patients because it does not differentiate between muscle and fat mass or provide information about body fat distribution. More sophisticated methods of body composition analysis are therefore required to address the question of which component is associated with greater survival. Recent evidence has also shown that changes in body weight and body composition are more strongly associated with mortality in dialysis patients than measurement of BMI at a single time point. Given that obesity is common among the dialysis population, weight loss interventions are encouraged for obese dialysis patients who are on a transplant waiting list in order to increase the access for transplantation.

Nonpharmacological Interventions for Depressive Symptoms in End-Stage Renal Disease: A Systematic Review

Depressive symptoms are common in patients with end-stage renal disease, which can affect treatment and prognosis. We aimed to evaluate the effects of nonpharmacological interventions for depressive symptoms in end-stage renal disease. Eligible studies were identified using PubMed, Web of Science, the Cochrane Library, Embase, and PsycNET (up to March 2019). We identified 24 studies including 1,376 patients. We found that psychological intervention (-0.60, 95% confidence interval [CI] = [-0.87, -0.33]), exercise (-1.13, 95% CI = [-1.56, -0.69]), and manual acupressure (-0.26, 95% CI = [-0.50, 0.03]) were associated with a significant effect on depressive symptoms. However, few studies reported adverse events, and conclusions about safety should be drawn cautiously. While the available data show that nonpharmacological interventions are potential strategies to alleviate depressive symptoms of patients with end-stage renal disease, recommendation of the most efficacious interventions for this population will require future randomized controlled trials with large-scale, long-term intervention.

Blood Pressure and Incident Atrial Fibrillation in Older Patients Initiating Hemodialysis

BACKGROUND AND OBJECTIVES

We examined the association of predialysis systolic and diastolic BP and intradialytic hypotension with incident atrial fibrillation in older patients initiating hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the US Renal Data System linked to the records of a large dialysis provider to identify patients aged ≥67 years initiating hemodialysis between January 2006 and October 2011. We examined quarterly average predialysis systolic BP, diastolic BP, and proportion of sessions with intradialytic hypotension (i.e., nadir systolic BP <90 mm Hg). We applied an extended Cox model to compute adjusted hazard ratios (HRs) of each exposure with incident atrial fibrillation.

RESULTS

Among 17,003 patients, 3785 developed atrial fibrillation. When comparing predialysis systolic BP to a fixed reference of 140 mm Hg, lower predialysis systolic BP was associated with a higher hazard of atrial fibrillation, whereas higher systolic BP was associated with a lower hazard of atrial fibrillation. When comparing across a range of systolic BP for two hypothetical patients with similar measured covariates, the association varied by mean systolic BP: at systolic BP 190 mm Hg, each 10 mm Hg lower systolic BP was associated with lower atrial fibrillation hazard (HR, 0.94; 95% confidence interval, 0.90 to 1.00), whereas at systolic BP 140 mm Hg, a 10 mm Hg lower systolic BP was associated with a higher atrial fibrillation hazard (HR, 1.12; 95% confidence interval, 1.10 to 1.14). Lower diastolic BP was associated with higher atrial fibrillation hazards. Intradialytic hypotension was weakly associated with atrial fibrillation.

CONCLUSIONS

In this observational study of older patients initiating hemodialysis, lower predialysis systolic BP and diastolic BP were associated with higher incidence of atrial fibrillation.

Timing of blood pressure medications and intradialytic hypotension

Intradialytic hypotension (IDH) is a prevalent yet serious complication of hemodialysis, associated with decreased quality of life, inadequate dialysis, vascular access thrombosis, global hypoperfusion, and increased cardiovascular and all-cause mortality. Current guidelines recommend antihypertensive medications be given at night and held the morning of dialysis for affected patients. Despite little evidence to support this recommendation, more than half of patients on dialysis may employ some form of this method. In this article, we will review the available evidence and clinical considerations regarding timing of blood pressure medications and occurrence of IDH, and conclude that witholding BP medications before hemodialysis should not be a routine practice.

Prognostic value of pre-dialysis blood pressure and risk threshold on clinical outcomes in hemodialysis patients: The Q-Cohort Study

The influence of pre-dialysis blood pressure (BP) on the prognosis of hemodialysis (HD) patients is still inconclusive.A total of 3436 HD patients were prospectively followed up for 4 years. The patients were divided into quintiles of pre-dialysis systolic BP (SBP) and diastolic BP (DBP) levels [mm Hg]: Quintile 1 (Q1), SBP <134, DBP <66; Q2, SBP 134 to 147, DBP 66 to 72; Q3, SBP 148 to 158, DBP 73 to 79; Q4, SBP 159 to 171, DBP 80 to 85; Q5, SBP ≥172, DBP ≥86. The association between the pre-dialysis BP and outcomes were examined using a Cox proportional hazards model.During a 4-year follow-up period, 564 (16.4%) patients died of any cause and 590 (17.2%) developed cardiovascular (CV) events. The lowest level of pre-dialysis SBP group (Q1) showed a significantly increased risk of all-cause mortality (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.40-2.39) and the highest group (Q5) significantly increased risk of CV events (HR 1.31, 95% CI 1.02-1.68) compared with the reference group (Q3), respectively. The highest level of pre-dialysis DBP group was significantly associated with increased risk for both all-cause mortality and CV events. Restricted cubic spline analysis for BP and outcomes suggested the optimal pre-dialysis BP value associated with the lowest risk of outcomes was SBP 152 mm Hg for all-cause mortality, SBP 143 mm Hg for CV events, and DBP 68 mm Hg for all-cause mortality.Our results suggested that pre-dialysis BP was independently associated with all-cause mortality and CV events among Japanese HD patients.

The Optimal Blood Pressure Target in Different Dialysis Populations

Hypertension is common and contributes to adverse outcomes in patients undergoing dialysis. However, the proper blood pressure (BP) target remains controversial and several factors make this difficult. This study aimed to investigate the adequate BP target in patients undergoing prevalent dialysis. Data were retrieved from the Clinical Research Center for End-Stage Renal Disease (2009–2014). 2,299 patients undergoing dialysis were evaluated. Patients were assigned into eight groups according to predialysis systolic blood pressure (SBP). The primary outcome was all-cause mortality. During the median follow-up of 4.5 years, a U-shape relation between SBP and mortality was found. The risk of mortality was increased in the SBP <110 and ≥170 mmHg groups. In subgroup analysis, the risk of mortality was similarly shown U-shape with SBP in subjects with no comorbidities, and no use of antihypertensive agents. However, only lowest SBP was a risk factor for mortality in patients with older, having diabetes or coronary artery disease, whereas highest SBP was an only risk factor in younger patients. In respect of dialysis characteristics, patients undergoing hemodialysis showed U-shape between SBP and mortality, while patients undergoing peritoneal dialysis did not. Among hemodialysis patients, patients with shorter dialysis vintage and less interdialytic weight gain showed U-shape association between SBP and mortality. This study showed that the lowest or highest SBP group had higher risk of mortality. Nevertheless, the optimal target BP should be applied according to individual condition of each patient.

Peridialysis BP levels and risk of all-cause mortality: a dose-response meta-analysis

Blood pressure (BP) management posed great challenge in hemodialysis (HD) population. We conducted a dose-response meta-analysis to investigate the quantitative features and the potential threshold effect of the associations between peridialysis BP levels and all-cause mortality risk in HD population. We searched all of the prospective cohort studies (published before 18 March 2017) on the associations between peridialysis BP levels and all-cause mortality risk. A total of 229,688 prevalent HD patients from 8 studies were included. Significant non-linear associations were noted between peridialytic BP levels and all-cause mortality risk. Significant increased risk of death was found in four peridialysis BP ranges, that is, low levels of predialysis SBP (<135 mmHg, 140 mmHg as the reference), two extremes of predialysis DBP (<55 and >95 mmHg, 90 mmHg as the reference), high levels of postdialysis SBP (>180 mmHg, 130 mmHg as the reference), and low levels of postdialysis DBP (<75 mmHg, 80 mmHg as the reference). Threshold effect was determined in the associations between peridialysis BP and all-cause mortality risk, and potential BP thresholds were identified (149 mmHg for predialysis SBP, 79 mmHg for predialysis DBP, 147 mmHg for postdialysis SBP and 76 mmHg for postdialysis DBP). In conclusion, the proposed peridialysis BP ranges and the threshold values could help clinicians identify high risk HD patients. The interpretation of the peridialysis BP mortality associations should be based on the features of HD population (especially the cardiovascular conditions, volume status and the dialysis vintage).

Impact of intradialytic blood pressure changes on cardiovascular outcomes is independent of the volume status of maintenance hemodialysis patients

Intradialytic systolic blood pressure (SBP) changes are related to the volume status; however, whether SBP change impacts on adverse outcomes depends on the volume status remains uncertain. We retrospectively investigated the relationship among intradialytic changes in SBP, cardiovascular outcomes, and volume status in maintenance hemodialysis patients. We determined SBP changes (ΔSBP) as postdialysis SBP minus predialysis SBP and volume status as the ratio of extracellular water to total body water (ECW/TBW) using bioelectrical impedance analysis. There were 82 (60.3%) with ΔSBP -20 to 10 mm Hg, 21 (15.4%) with ΔSBP ≤ -20 mm Hg, and 33 (24.3%) with ΔSBP ≥ 10 mm Hg, and they were followed up for a median of 34 months. Cardiovascular events more frequently occurred in the patients with ΔSBP ≤ -20 mm Hg and ≥ 10 mm Hg (hazard ratio: 2.3 and 3.0; P = .062 and .006); these associations persisted even after adjusting for postdialysis ECW/TBW (P = .056 and .028). Moreover, ΔSBP ≥ 10 mm Hg was associated with increased cardiovascular mortalities independent of postdialysis ECW/TBW (P = .043). There was an independent association of volume status between considerable SBP decrease or increase during hemodialysis and adverse cardiovascular outcomes. Besides appropriate volume control, other factors related to BP changes during hemodialysis must be investigated.

Hemodialysis versus peritoneal dialysis: an observational study in two international centers

INTRODUCTION

Given that it is difficult to randomize end-stage renal disease (ESRD) patients to either hemodialysis (HD) or peritoneal dialysis (PD), differences between these renal replacement therapy (RRT) modalities are of major interest and remain controversial.

METHODS

All data on maintenance dialysis patients during 2009 to 2013 in the Renji Hospital in Shanghai, China and in the San Bortolo Hospital in Vicenza, Italy were selected. Patients who changed their therapy from HD to PD or PD to HD during this study were excluded.

RESULTS

919 maintenance dialysis patients were included in the present study, including 509 patients on HD and 410 on PD. During the 5-year follow-up, mean arterial pressure (MAP) was higher in HD patients. The level of serum HCO3- was significantly better in PD patients than in HD patients. Phosphate was significantly higher in HD patients than in PD patients. With respect to lipid metabolism, triglyceride, total cholesterol and LDL were significantly higher in PD patients. Serum protein and albumin were higher in HD patients than in PD patients. Overall, 236 patients died (25.7%); 150 (16.3%) on HD and 86 (9.4%) on PD. The main cause of death in HD and PD patients was cerebral vascular disease and infection, respectively. After adjusting for dialysis vintage, the Kaplan-Meier patient survival was similar between HD and PD patients.

CONCLUSIONS

Based on 5 years of data, we demonstrate that lipid metabolism and nutritional status were better in HD patients. However, blood pressure control, acid-base balance, phosphate (P) control were better in PD patients. The main cause of death in HD and PD was cerebral vascular disease and infection, respectively. Considering the dialysis vintage, the Kaplan-Meier patient survival was similar between HD and PD patients.

Evolution of Cardiovascular Disease During the Transition to End-Stage Renal Disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The rate of death in incident dialysis patients remains high. This has led to interest in the study of the evolution of CVD during the critical transition period from CKD to ESRD. Understanding the natural history and risk factors of clinical and subclinical CVD during this transition may help guide the timing of appropriate CVD therapies to improve outcomes in patients with kidney disease. This review provides an overview of the epidemiology of subclinical and clinical CVD during the transition from CKD to ESRD and discusses clinical trials of CVD therapies to mitigate risk of CVD in CKD and ESRD patients.

Multiphasic effects of blood pressure on survival in hemodialysis patients

Dialysis patients exhibit an inverse, L- or U-shaped association between blood pressure and mortality risk, in contrast to the linear association in the general population. We prospectively studied 9333 hemodialysis patients in France, aiming to analyze associations between predialysis systolic, diastolic, and pulse pressure with all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular endpoints for a median follow-up of 548 days. Blood pressure components were tested against outcomes in time-varying covariate linear and fractional polynomial Cox models. Changes throughout follow-up were analyzed with a joint model including both the time-varying covariate of sequential blood pressure and its slope over time. A U-shaped association of systolic blood pressure was found with all-cause mortality and of both systolic and diastolic blood pressure with cardiovascular mortality. There was an L-shaped association of diastolic blood pressure with all-cause mortality. The lowest hazard ratio of all-cause mortality was observed for a systolic blood pressure of 165 mm Hg, and of cardiovascular mortality for systolic/diastolic pressures of 157/90 mm Hg, substantially higher than currently recommended values for the general population. The 95% lower confidence interval was approximately 135/70 mm Hg. We found no significant correlation for either systolic, diastolic, or pulse pressure with myocardial infarction or nontraumatic amputations, but there were significant positive associations between systolic and pulse pressure with stroke (per 10-mm Hg increase: hazard ratios 1.15, 95% confidence interval 1.07 and 1.23; and 1.20, 1.11 and 1.31, respectively). Thus, whereas high pre-dialysis blood pressure is associated with stroke risk, low pre-dialysis blood pressure may be both harmful and a proxy for comorbid conditions leading to premature death.

Blood Pressure and Risk of Cardiovascular Events in Patients on Chronic Hemodialysis: The CRIC Study (Chronic Renal Insufficiency Cohort)

We recently reported a linear association between higher systolic blood pressure (SBP) and risk of mortality in hemodialysis patients when SBP is measured outside of the dialysis unit (out-of-dialysis-unit-SBP), despite there being a U-shaped association between SBP measured at the dialysis unit (dialysis-unit-SBP) with risk of mortality. Here, we explored the relationship between SBP with cardiovascular events, which has important treatment implications but has not been well elucidated. Among 383 hemodialysis participants enrolled in the prospective CRIC study (Chronic Renal Insufficiency Cohort), multivariable splines and Cox models were used to study the association between SBP and adjudicated cardiovascular events (heart failure, myocardial infarction, ischemic stroke, and peripheral artery disease), controlling for differences in demographics, cardiovascular disease risk factors, and dialysis parameters. Dialysis-unit-SBP and out-of-dialysis-unit-SBP were modestly correlated (r=0.34; P<0.001). We noted a U-shaped association of dialysis-unit-SBP and risk of cardiovascular events, with the nadir risk between 140 and 170 mm Hg. In contrast, there was a linear stepwise association between out-of-dialysis-unit-SBP with risk of cardiovascular events. Participants with out-of-dialysis-unit-SBP ≥128 mm Hg (top 2 quartiles) had >2-fold increased risk of cardiovascular events compared with those with out-of-dialysis-unit-SBP ≤112 mm Hg (3rd SBP quartile: adjusted hazard ratio, 2.08 [95% confidence interval, 1.12-3.87] and fourth SBP quartile: adjusted hazard ratio, 2.76 [95% confidence interval, 1.42-5.33]). In conclusion, among hemodialysis patients, although there is a U-shaped (paradoxical) association of dialysis-unit-SBP and risk of cardiovascular disease, there is a linear association of out-of-dialysis-unit-SBP with risk of cardiovascular disease. Out-of-dialysis-unit blood pressure provides key information and may be an important therapeutic target.

Blood Pressure and Mortality in Long-Term Hemodialysis-Time to Move Forward

Contrary to the direct, graded, and causal relationship of hypertension with cardiovascular outcomes in the general population, among dialysis patients, blood pressure (BP) recorded either predialysis or postdialysis displays a U-shaped curve with mortality. This paradoxical phenomenon of lower BP or a decline in BP over time being associated with increased mortality and higher BP being associated with a lower mortality is described as "reverse" epidemiology of hypertension, raising substantial controversy on whether BP lowering causes harms or benefits among dialysis patients. Unlike the inverse relationship of peridialytic BP with mortality, elevated BP recorded outside of dialysis is directly associated with poor long-term outcomes. Apart from the timing and technique of BP measurement, the U-shaped association of BP with mortality is also modified when accounting for factors related to patient's clinical characteristics and level of illness, dialysis practices, and patterns as well as factors related to the methodology of survival analysis. Most importantly, deliberate BP lowering with antihypertensive drugs is associated with reduced cardiovascular morbidity and mortality. In this review, we explore the complex association of peridialytic, intradialytic, and interdialytic BP with outcomes among dialysis patients. We conclude with recommendations for a wider use of out-of-dialysis BP monitoring as a tool to better evaluate the cardiovascular risk and optimize the management of hypertension in this high-risk population. Rather than more cohort studies, we call for randomized trials to test the level of BP in dialysis patients that is optimal for cardiovascular outcomes.

The influence of time point of blood pressure measurement on the outcome in hemodialysis patients

The blood pressure (BP) behaviors of hemodialysis (HD) population presented a unique pattern much different from that of the general population. This pattern is composed of chronic BP burden over interdialytic period and acute BP fluctuation during dialysis sessions. Peridialysis, interdialysis, and intradialysis are three routinely used time points to capture this complex BP behavior. However, BP at each time point was measured in various forms and conveyed different prognostic information. The measurement and interpretation of the tide-like BP behavior in HD population posed great challenge. In this review, we focused on the prognostic information of the BP behavior at each time point in HD patients and further discussed the optimal measurement of this unique BP behavior to best capture the BP-outcome association.

Efficacy of Losartan in the management of Post-Dialysis Euvolemic Hypertension (HELD-Trial): A Single-Blind Randomized Control Trial

To assess the effectiveness of losartan 50 mg on post dialysis euvolemic hypertensive patients against standard antihypertensive pharmacotherapy. A multicentre, prospective, randomized, single-blind trial was conducted to assess the effect of losartan 50 mg every other day (EOD), once a morning (OM) among post-dialysis euvolemic hypertensive patients. Covariate-adaptive randomization was used to allocate participants to a standard or treatment arm, and they were followed up for eight weeks. Pre-, intra- and post-dialysis session blood pressure (BP) measurements were recorded along with any adverse events. A total of 88 patients were randomized into standard (n = 44) and treatment arms (n = 44) and were followed for a period of 8 weeks. In the standard group, the mean post-dialysis blood pressure dropped by 0.3 mmHg by the end of the 8^th week. However the treatment arm reported a drop of 2.4 mmHg of BP drop during the 8-week trial period. Analysis suggests that there was a significant difference in blood pressure readings at the end of 8 weeks among patients treated with losartan (P < 0.001). However, no such statistical association was observed in the standard arm (P 0.75). A slow, steady significant decline in post-dialysis BP was observed among euvolemic hypertensive patients that were treated with losartan 50 mg.

Antidepressants for treating depression in adults with end-stage kidney disease treated with dialysis

BACKGROUND

Depression affects approximately one-quarter of people treated with dialysis and is considered an important research uncertainty by patients and health professionals. Treatment for depression in dialysis patients may have different benefits and harms compared to the general population due to different clearances of antidepressant medication and the severity of somatic symptoms associated with end-stage kidney disease (ESKD). Guidelines suggest treatment of depression in dialysis patients with pharmacological therapy, preferably a selective serotonin reuptake inhibitor. This is an update of a review first published in 2005.

OBJECTIVES

To evaluate the benefit and harms of antidepressants for treating depression in adults with ESKD treated with dialysis.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 20 January 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antidepressant treatment with placebo or no treatment, or compared to another antidepressant medication or psychological intervention in adults with ESKD (estimated glomerular filtration rate < 15 mL/min/1.73 m(2)).

DATA COLLECTION AND ANALYSIS

Data were abstracted by two authors independently onto a standard form and subsequently entered into Review Manager. Risk ratios (RR) for dichotomous data and mean differences (MD) for continuous data were calculated with 95% confidence intervals (95% CI).

MAIN RESULTS

Four studies in 170 participants compared antidepressant therapy (fluoxetine, sertraline, citalopram or escitalopram) versus placebo or psychological training for 8 to 12 weeks. In generally very low or ungradeable evidence, compared to placebo, antidepressant therapy had no evidence of benefit on quality of life, had uncertain effects on increasing the risk of hypotension (3 studies, 144 participants: RR 1.72, 95% CI 0.75 to 3.92), headache (2 studies 56 participants: RR 2.91, 95% CI 0.73 to 11.57), and sexual dysfunction (2 studies, 101 participants: RR 3.83, 95% CI 0.63 to 23.34), and increased nausea (3 studies, 114 participants: RR 2.67, 95% CI 1.26 to 5.68). There were few or no data for hospitalisation, suicide or all-cause mortality resulting in inconclusive evidence. Antidepressant therapy may reduce depression scores during treatment compared to placebo (1 study, 43 participants: MD -7.50, 95% CI -11.94 to -3.06). Antidepressant therapy was not statistically different from group psychological therapy for effects on depression scores or withdrawal from treatment and a range of other outcomes were not measured.

AUTHORS' CONCLUSIONS

Despite the high prevalence of depression in dialysis patients and the relative priority that patients place on effective treatments, evidence for antidepressant medication in the dialysis setting is sparse and data are generally inconclusive. The relative benefits and harms of antidepressant therapy in dialysis patients are poorly known and large randomised studies of antidepressants versus placebo are required.

Blood Pressure and Mortality in Hemodialysis Patients: A Systematic Review of an Ongoing Debate

Hypertension is prevalent in 75-80% of hemodialysis patients and remains the most controversial prognostic marker in end stage kidney disease patients. In contrast to the general population where systolic blood pressure of ≤120 mm Hg is considered normal, a debate remains regarding the ideal target blood pressure in hemodialysis patients. Using the PUBMED and EMBASE databases, the research studies that evaluated the relationship between blood pressure measurements and mortality in hemodialysis patients were searched. Thirteen studies were identified from different regions of the world. Five studies reported low predialysis systolic blood pressure as a prognostic marker of mortality. Other studies showed varying results and reported postdialysis systolic blood pressure as well as ambulatory blood pressure as better predictors of mortality and emphasized their optimized control. One study in this review concluded that there is no direct relationship between mortality and blood pressure if the patients are on anti-hypertensive medications. The observed all-cause mortality varied from 12% to 36%, whereas the cardiovascular mortality varied from 16% to 60%. On the basis of studies included in the current review, a low predialysis systolic blood pressure (<120 mm Hg) is shown to be a widely accepted prognostic marker of mortality while ambulatory blood pressure best predicts CV mortality. Therefore, we recommend that apart from routine BP (pre, post and intradialysis) monitoring in centers, assessment of ambulatory BP must be mandatory for all patients to reduce CV mortality in hemodialysis patients.

Computer Aided Detection System for Prediction of the Malaise during Hemodialysis

Monitoring of dialysis sessions is crucial as different stress factors can yield suffering or critical situations. Specialized personnel is usually required for the administration of this medical treatment; nevertheless, subjects whose clinical status can be considered stable require different monitoring strategies when compared with subjects with critical clinical conditions. In this case domiciliary treatment or monitoring can substantially improve the quality of life of patients undergoing dialysis. In this work, we present a Computer Aided Detection (CAD) system for the telemonitoring of patients' clinical parameters. The CAD was mainly designed to predict the insurgence of critical events; it consisted of two Random Forest (RF) classifiers: the first one (RF₁) predicting the onset of any malaise one hour after the treatment start and the second one (RF₂) again two hours later. The developed system shows an accurate classification performance in terms of both sensitivity and specificity. The specificity in the identification of nonsymptomatic sessions and the sensitivity in the identification of symptomatic sessions for RF₂ are equal to 86.60% and 71.40%, respectively, thus suggesting the CAD as an effective tool to support expert nephrologists in telemonitoring the 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

BACKGROUND

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.

STUDY DESIGN

National prospective cohort study.

SETTING & PARTICIPANTS

446 incident hemodialysis patients.

PREDICTOR

Predialysis systolic BP.

OUTCOMES

Mortality (all-cause and CVD) and first CVD event assessed using Cox regression adjusted for demographics, comorbid conditions, and clinical factors.

MEASUREMENTS

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.

RESULTS

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.

LIMITATIONS

BP measurements not standardized.

CONCLUSIONS

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.

Design of the Blood Pressure Goals in Dialysis pilot study

BACKGROUND

Cardiovascular disease (CVD) is markedly increased among hemodialysis (HD) patients. Optimizing blood pressure (BP) among HD patients may present an important opportunity to reduce the disparity in CVD rates between HD patients and the general population. The optimal target predialysis systolic BP (SBP) among HD patients is unknown. Current international guidelines, calling for a predialysis SBP < 140 mm Hg, are based on the opinion and extrapolation from the general population. Existing randomized controlled trials (RCTs) were small and did not include prespecified BP targets.

METHODS

The authors described the design of the Blood Pressure in Dialysis (BID) Study, a pilot, multicenter RCT where HD patients are randomized to either a target-standardized predialysis SBP of 110 to 140 mm Hg or 155 to 165 mm Hg. This is the first study to randomize HD patients to 2 different SBP targets.

RESULTS

Primary outcomes are feasibility and safety. Feasibility parameters include recruitment and retention rates, adherence with prescribed BP measurements and achievement and maintenance of selected BP targets. Safety parameters include rates of hypotension and other adverse and serious adverse events. The authors obtained preliminary data on changes in left ventricular mass, aortic pulse wave velocity, vascular access thromboses and health-related quality of life across study arms, which may be the secondary outcomes in the full-scale study.

CONCLUSIONS

The data acquired in the pilot RCT will determine the feasibility and safety and inform the design of a full-scale trial, powered for hard outcomes, which may require 2000 participants.

Risk of sudden cardiac death in chronic kidney disease

The review discusses the epidemiology and the possible underlying mechanisms of sudden cardiac death (SCD) in chronic kidney disease (CKD), and highlights the unmet clinical need for noninvasive risk stratification strategies in these patients. Although renal dysfunction shares common risk factors and often coexists with atherosclerotic cardiovascular disease, the presence of renal impairment increases the risk of arrhythmic complications to an extent that cannot be explained by the severity of the atherosclerotic process. Renal impairment is an independent risk factor for SCD from the early stages of CKD; the risk increases as renal function declines and reaches very high levels in patients with end-stage renal disease on dialysis. Autonomic imbalance, uremic cardiomyopathy, and electrolyte disturbances likely play a role in increasing the arrhythmic risk and can be potential targets for treatment. Cardioverter defibrillator treatment could be offered as lifesaving treatment in selected patients, although selection strategies for this treatment mode are presently problematic in dialyzed patients. The review also examines the current experience with risk stratification tools in renal patients and suggests that noninvasive electrophysiological testing during dialysis may be of clinical value as it provides the necessary standardized environment for reproducible measurements for risk stratification purposes.

Hydration measurement by bioimpedance spectroscopy and blood pressure management in children on hemodialysis

BACKGROUND

Hypertension is frequent in chronic hemodialyzed patients and usually treated by reducing extracellular fluid. Probing dry weight only based on a clinical evaluation may be hazardous, especially in case of volume independent hypertension.

METHODS

We performed a 1-year retrospective study in three pediatric centers to define the relation between blood pressure (BP) and hydration status, assessed by whole-body bioimpedance spectroscopy (BIS). We analyzed 463 concomitant measurements of BP, relative overhydration (rel.OH), and plasma sodium (Napl) in 23 children (mean age 13.9 ± 5.1 years).

RESULTS

Pre-dialytic under-hydration (rel.OH < -7%) was present in 5.4% of the sessions, out of which 24% showed hypertension. Normohydration (rel.OH -7 - +7%) was observed in 62.4% of the sessions, 45.3% of them revealed hypertension. Moderate OH (rel.OH +7 - +15%) was present in 21% of the sessions, 47.4% of them showed normal BP. In 11.2% of the sessions, severe overhydration (rel.OH > +15%) was assessed, however, the majority (73%) showed normal BP. Patient-specific Napl setpoint could not be described. Mean dialysate sodium concentration was higher than mean Napl.

CONCLUSIONS

Hypertension is not always related to overhydration. Therefore, BIS should restrict the practice of "probing dry weight" in hypertensive children. Moreover, sodium dialytic balance needs to be considered to improve BP management.

Visit-to-visit systolic blood pressure variability and outcomes in hemodialysis

Visit-to-visit blood pressure variation (VTV-BPV) is an independent risk factor for cardiovascular events and death in the general population. We sought to determine the association of VTV-BPV with outcomes in patients on hemodialysis, using data from a National Institutes of Health-sponsored randomized trial (the HEMO Study). We used the coefficient of variation (CV) and the average real variability (ARV) in systolic blood pressure (SBP) as metrics of VTV-BPV. 1844 of 1846 randomized subjects had at least three visits with SBP measurements and were included in the analysis. Median follow-up was 2.5 years (interquartile range [IQR] 1.3 to 4.3 years), during which time there were 869 deaths from any cause and 408 (adjudicated) cardiovascular deaths. The mean pre-dialysis SBP CV was 9.9% ± 4.6%. In unadjusted models, we found a 31% higher risk of death from any cause per 10% increase in VTV-BPV. This association was attenuated after multivariable adjustment but remained statistically significant. Similarly, we found a 28% higher risk of cardiovascular death per 10% increase in VTV-BPV, which was attenuated and no longer statistically significant in fully adjusted models. The associations among VTV-BPV, death and cardiovascular death were modified by baseline SBP. In a diverse, well-dialyzed cohort of patients on maintenance hemodialysis, VTV-BPV, assessed using metrics of variability in pre-dialysis SBP, was associated with a higher risk of all-cause mortality and a trend towards higher risk of cardiovascular mortality, particularly in patients with a lower baseline SBP.

Blood pressure and blood volume: acute and chronic considerations in hemodialysis

Hypertension is highly prevalent yet poorly controlled in the majority of dialysis patients and represents a significant burden of disease, with rates of morbidity and mortality greater than those in the general population. In dialysis, blood volume plays a critical role in the pathogenesis of hypertension, with expansion of extracellular volume increasingly recognized as an independent risk factor for morbidity and mortality. Within the current paradigm of dialysis prescription the majority of patients remain chronically volume expanded. However, management of blood pressure and volume state is difficult for clinicians with a paucity of randomized evidence adding to the complexity of nonlinear morbidity and mortality associations. With dialysis itself as a significant cardiac stressor, control of volume state is critical to minimize intradialytic hemodynamic instability, aid in preservation of cardiac anatomy and prevent progression to cardiovascular morbidity and mortality. This review explores the relationship of blood volume to blood pressure and potential targets for management in this at risk population.

Systolic blood pressure and mortality in patients on hemodialysis

Hypertension is extremely common in patients with end-stage renal disease who are receiving hemodialysis, and cardiovascular disease remains the leading cause of death in these patients. However, optimal blood pressure management strategies in this high-risk population are still controversial. This review first discusses the complex association of systolic blood pressure with clinical outcomes in patients on hemodialysis, with a focus on several recent studies. Next, it updates the reader on issues related to optimal timing and methods of blood pressure measurement, appropriate blood pressure targets, and pharmacologic and nonpharmacologic hypertension treatment strategies for patients on hemodialysis.

Systolic blood pressure at Emergency Department presentation and 1-year mortality in acute chest pain patients

BACKGROUND

High blood pressure at rest has been an established risk factor for cardiovascular disease. However the relationship between Systolic Blood Pressure (SBP) and 1-year-mortality among acute chest pain patients presenting to Emergency Department (ED); and effects of preexisting renal insufficiency, hemodynamic stress - as quantified by Brain Natriuretic Peptide (BNP) and chest pain duration, on this relationship is unknown.

METHODS

Data was used from APACE (Advantageous Predictors of Acute Coronary Syndrome Evaluation), a prospective observational multicenter study of 1240 ED chest pain patients. SBP at presentation was categorized into quartiles: Q1≤127mmHg; Q2 128-142mmHg; Q3 143-160mmHg; Q4≥161mmHg.

RESULTS

60 deaths occurred during 1-year. One-year-mortality-rate showed lower Hazard Ratios for Q2, Q3 and Q4 vs Q1 (HR [95% CI]; 0.39 (0.19-0.78), 0.34 (0.17-0.70), 0.35 (0.17-0.72); p<0.01 respectively). Cox model adjusted for various demographic and treatment variables showed that participants in Q3 and Q4 had better prognoses than Q1. Patients showed progressively better prognosis from Q2 through Q4 vs Q1 only in patients who presented to ED with for more than 12h of chest pain duration. Patients with renal insufficiency had lower SBP at presentation than others (p=0.001). There was no association between the outcome and interaction variable of SBP quartiles and BNP (p=0.27).

CONCLUSION

Acute chest pain patients presenting to ED exhibit an inverse association between SBP at presentation and 1-year-mortality; a relationship which appears stronger in those who present with chest pain of greater than 12h duration.

Intradialytic hypotension and vascular access thrombosis

Identifying potential modifiable risk factors to reduce the incidence of vascular access thrombosis in hemodialysis could reduce considerable morbidity and health care costs. We analyzed data from a subset of 1426 HEMO study subjects to determine whether more frequent intradialytic hypotension and/or lower predialysis systolic BP were associated with higher rates of vascular access thrombosis. Our primary outcome measure was episodes of vascular access thrombosis occurring within a given 6-month period during HEMO study follow-up. There were 2005 total episodes of vascular access thrombosis during a median 3.1 years of follow-up. The relative rate of thrombosis of native arteriovenous fistulas for the highest quartile of intradialytic hypotension was approximately twice that of the lowest quartile, independent of predialysis systolic BP and other covariates. There was no significant association of intradialytic hypotension with prosthetic arteriovenous graft thrombosis after multivariable adjustment. Higher predialysis systolic BP was associated with a lower rate of fistula and graft thrombosis, independent of intradialytic hypotension and other covariates. In conclusion, more frequent episodes of intradialytic hypotension and lower predialysis systolic BP associate with increased rates of vascular access thrombosis. These results underscore the importance of including vascular access patency in future studies of BP management in hemodialysis.

A model of systolic blood pressure during the course of dialysis and clinical factors associated with various blood pressure behaviors

BACKGROUND

Little is known about the behavior of systolic blood pressure (SBP) during hemodialysis.

STUDY DESIGN

Prospective observational cohort.

SETTING & PARTICIPANTS

218 prevalent hemodialysis patients treated at 5 participating DaVita Dialysis units.

PREDICTORS

Clinical variables that may plausibly influence the behavior of SBP during the course of hemodialysis sessions.

OUTCOMES

SBP at the onset of dialysis and its rate of change (slope) over the first 25% and latter 75% of the treatment interval.

MEASUREMENTS

SBPs measured and recorded per clinical protocol during the first 30 days of study (median, 11 treatments/patient; SBP measured at 30-minute intervals).

RESULTS

Intradialytic SBP behavior is well characterized by a 2-slope linear spline model, which describes SBP at time zero, a rapid decrease during the first 25% of the treatment (early), and a more gradual decrease thereafter (late). Higher ultrafiltration volume and rate each are associated with greater SBP at the start of dialysis and more rapid early and late SBP decreases. Use of a higher number of antihypertensives was associated with greater time zero SBP. Calcium acetate use is associated with high SBP at the start of hemodialysis and a more pronounced decrease during the early and late parts of treatment.

LIMITATIONS

Over-representation of blacks and patients with congestive heart failure; observational design; use of clinically measured blood pressures.

CONCLUSIONS

Intradialytic SBP can be characterized using 3 parameters: value at the start of dialysis and slopes during the first 25% and latter 75% of treatment. Practices related to fluid management, antihypertensive use, and metabolic bone disease control are associated with blood pressure behavior during dialysis. Further work is needed to confirm findings and measure associations between various aspects of intradialytic blood pressure behavior and clinical outcomes.

The fluid study protocol: a randomized controlled study on the effects of bioimpedance analysis and vitamin D on left ventricular mass in peritoneal dialysis patients

OBJECTIVES

We will evaluate the effects of bioimpedance analysis-guided fluid management to reduce volume expansion, of vitamin D(3) supplementation, and of the combination of those techniques on decrease of left ventricular mass in peritoneal dialysis (PD) patients.

DESIGN

This multicenter randomized controlled trial, with a 2 × 2 factorial design, will be conducted at PD clinics affiliated with 3 Canadian teaching hospitals. Consenting PD patients 18 years of age or older will be included. Patients will be excluded if they have contraindications to bioimpedance or magnetic resonance imaging, life or technique expectancy of less than 1 year, peritonitis within the preceding 3 months, or serum calcium above 2.55 mmol/L.

INTERVENTION

The study will randomize 70 patients to bio-impedance-guided volume management or to usual care and to vitamin D(3) 50,000 U weekly for 8 doses, and then 10,000 U weekly or to matching placebo.

MAIN OUTCOME MEASURES

The primary outcome will be change in left ventricular mass at 1 year as determined by cardiac magnetic resonance imaging. The secondary outcome will be a composite endpoint of death, nonfatal cardiovascular event, and transfer to hemodialysis for dialysis inadequacy or ultrafiltration failure. Other outcome measures will include blood pressure, quality of life, 6-minute walk test, inflammatory and fibrotic markers and their association with peritoneal membrane transport properties, and residual renal function. Patients will be followed for clinical outcomes for up to 3 years.

CONCLUSIONS

This study will assess whether bioimpedance-directed volume management and vitamin D(3) supplementation can improve left ventricular mass in PD patients.

Blood pressure and survival in long-term hemodialysis patients with and without polycystic kidney disease

BACKGROUND

In maintenance dialysis patients, low blood pressure (BP) values are associated with higher death rates when compared with normal to moderately high values. This 'hypertension paradox' may be related to comorbid conditions. Dialysis patients with polycystic kidney disease (PKD) usually have a lower comorbidity burden and greater survival. We hypothesized that in PKD dialysis patients, a representative of a healthier dialysis patient population, high BP is associated with higher mortality.

METHODS

Time-dependent survival models including after multivariate adjustment were examined to assess the association between prehemodialysis and posthemodialysis BP and all-cause mortality in a 5-year cohort of 67 085 non-PKD and 1579 PKD hemodialysis patients.

RESULTS

In PKD patients, low prehemodialysis and posthemodialysis SBPs were associated with increased mortality, whereas high prehemodialysis DBP was associated with greater survival. Fully adjusted death hazard ratios (and 95% confidence levels) for prehemodialysis and posthemodialysis BP of less than 120 mmHg (reference 140 to <160 mmHg) were 1.30 (1.06-1.92) and 1.45 (1.04-2.02), respectively, and for prehemodialysis DBP of 80 mmHg or more (reference 70 to <80 mmHg) was 0.68 (0.49-0.93, all P values <0.05). Similar associations were observed in non-PKD patients. In pooled analyses, within each commensurate BP stratum, PKD patients exhibited superior survival to non-PKD patients.

CONCLUSION

Among hemodialysis patients, those with PKD display a similar BP paradox as those without PKD, even though within each BP category PKD patients maintain superior survival. Randomized clinical trials are needed to define optimal blood pressure targets in the hemodialysis population.