Prevalence of hypertension in patients on peritoneal dialysis: results of an Italian multicentre study

Apparent Treatment-Resistant Hypertension in the First Year Associated With Cardiovascular Mortality in Peritoneal Dialysis Patients

BACKGROUND

Few reports have focused on the association between apparent treatment-resistant hypertension (aTRH) and cardiovascular (CV) mortality in peritoneal dialysis (PD) population, thus we conducted this retrospective cohort to explore it.

METHODS

This was a retrospective cohort study conducted from January 2011 to January 2020 with PD patients in 4 Chinese dialysis centers. aTRH was defined according to the American College of Cardiology and American Heart Association guidelines. aTRH duration was calculated as the total number of months when patients met the diagnostic criteria in the first PD year. The primary outcome was CV mortality, and the secondary outcomes were CV events, all-cause mortality, combined endpoint (all-cause mortality and transferred to hemodialysis [HD]), and PD withdrawal (all-cause mortality, transferred to HD, and kidney transplantation). Cox proportional hazards models were used to assess the association.

RESULTS

A total of 1,422 patients were finally included in the analysis. During a median follow-up period of 26 months, 83 (5.8%) PD patients incurred CV mortality. The prevalence of aTRH was 24.1%, 19.9%, and 24.6% at 0, 3, and 12 months after PD initiation, respectively. Overall, aTRH duration in the first PD year positively associated with CV mortality (per 3 months increment, adjusted hazards ratio [HR], 1.29; 95% confidence interval 1.10, 1.53; P = 0.002). After categorized, those with aTRH duration more than 6 months presented the highest adjusted HR of 2.92. Similar results were found for secondary outcomes, except for the CV event.

CONCLUSIONS

Longer aTRH duration in the first PD year is associated with higher CV mortality and worse long-term clinical outcomes. Larger studies are warranted to confirm these findings.

CLINICAL TRIALS REGISTRATION

There is no clinical trial registration for this retrospective study.

Transition between peritoneal dialysis modalities: Impact on blood pressure levels and drug prescription in a national multicentric cohort

BACKGROUND

Hypertension is a leading cause of kidney failure, affects most dialysis patients and associates with adverse outcomes. Hypertension can be difficult to control with dialysis modalities having differential effects on sodium and water removal. There are two main types of peritoneal dialysis (PD), automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD). It is unknown whether one is superior to the other in controlling blood pressure (BP). Therefore, the aim of our study was to analyse the impact of switching between these two PD modalities on BP levels in a nationally representative cohort.

METHODS

This was a cohort study of patients on PD from 122 dialysis centres in Brazil (BRAZPD II study). Clinical and laboratory data were collected monthly throughout the study duration. We selected all patients who remained on PD at least 6 months and 3 months on each modality at minimum. We compared the changes in mean systolic/diastolic blood pressures (SBP/DBP) before and after modality transition using a multilevel mixed-model where patients were at first level and their clinics at the second level.

RESULTS

We analysed data of 848 patients (814 starting on CAPD and 34 starting on APD). The SBP decreased by 4 (SD 22) mmHg when transitioning from CAPD to APD (p < 0.001) and increased by 4 (SD 21) mmHg when transitioning from APD to CAPD (p = 0.38); consistent findings were seen for DBP. There was no significant change in the number of antihypertensive drugs prescribed before and after transition.

CONCLUSIONS

Transition between PD modalities seems to directly impact on BP levels. Further studies are needed to confirm if switching to APD could be an effective treatment for uncontrolled hypertension among CAPD patients.

The superiority of bioimpedance vs. echocardiography and pitting edema in predicting automated office blood pressure in continuous ambulatory peritoneal dialysis patients

INTRODUCTION

To achieve optimal blood pressure control in continuous ambulatory peritoneal dialysis (CAPD) patients, identifying methods of volume assessment with the strongest correlation with blood pressure is essential.

METHODS

In this cross-sectional study, 52 CAPD patients were assigned to automated office blood pressure (AOBP) measurement, assessment of pedal pitting edema, bioimpedance analysis (BIA), and inferior vena cava collapsibility index (IVCCI%) measurement. Data were analyzed using STATA ver.17, and the significance level was p < 0.05.

RESULTS

Fifty-two patients were divided based on their AOBP readings. 29 (55.8%) of patients had uncontrolled AOBP. Overhydration (OH) and the grade of pitting edema were significantly higher in the uncontrolled AOBP group. OH was identified as the best variable for predicting blood pressure (p ≤ 0.001) and detecting uncontrolled blood pressure (AUC = 0.832) using multivariate linear regression and ROC analysis, respectively.

CONCLUSION

BIA-derived OH was the best variable for predicting systolic and diastolic AOBP, outperforming IVCCI% and pitting edema.

Why should we use a low sodium dialysis solution for peritoneal dialysis?

Overhydration is highly prevalent in patients on peritoneal dialysis (PD), with inappropriately high sodium load supposedly playing a central role in the pathophysiology of the conditions. Recent studies have revealed the novel role of the interstitium as a buffer system for sodium ions, and it has been reported that patients on dialysis, including PD, present increased levels of sodium in the interstitium, such as in subcutaneous tissue and muscle. Hence, therapy for correction of overhydration should target the excess extracellular volume and the excess sodium storage in the interstitium. The ultrafiltrate obtained using the currently available PD solutions is hypo- to isonatric as compared to serum, which is disadvantageous for prompt and efficient sodium removal from the body in patients with overhydration. In contrast, use of low sodium PD solutions is characterised by iso- to hypernatric ultrafiltrate, which may beneficial for reducing sodium storage in the interstitium. Trials of low sodium PD solutions have reported possible clinical merits, for example, decreased blood pressure, reduced dryness of mouth and decreased body water content as assessed using bioimpedance methods. Given these observations and the high prevalence of overhydration in current PD populations, it makes medical sense that low sodium solutions be positioned as the new standard solution in the future. However, for medical safety, that is, to avoid hyponatremia and excessive decreases in blood pressure, further studies are needed to establish the appropriate compositions and applications of low sodium solutions.

Home-Based Dialysis: A Primer for the Internist

Home-based dialysis modalities offer both clinical and practical advantages to patients. The use of the home-based modalities, peritoneal dialysis and home hemodialysis, has been increasing over the past decade after a long period of decline. Given the increasing frequency of use of these types of dialysis, it is important for clinicians to be familiar with how these types of dialysis are performed and key clinical aspects of care related to their use in patients with end-stage kidney disease.

Serum irisin levels are negatively associated with blood pressure in dialysis patients

Elevated blood pressure is highly prevalent among dialysis patients and is associated with high mortality. Irisin is a newly found myokine that has been indicated to be related to blood pressure regulation in animal experiments. Data regarding the effect of serum irisin levels on blood pressure in dialysis patients are limited. To identify the association between serum irisin levels and blood pressure and examine determinant factors of systolic blood pressure in dialysis patients, we recruited 300 dialysis patients at Xuanwu Hospital Capital Medical University. Serum irisin levels were assessed by enzyme-linked immunosorbent assay kits. Blood pressure was self-measured on 7 consecutive days by an automated sphygmomanometer. The Pearson correlation test showed that the natural logarithm of irisin was negatively correlated with systolic blood pressure (r = -0.462, P < 0.001) and pulse pressure (r = -0.487, P < 0.001), but not correlated with diastolic blood pressure (r = -0.022, P = 0.709). Multivariate analysis revealed that the natural logarithm of irisin (β = -0.336, P < 0.001), lean tissue mass (β = 0.164, P = 0.005), diabetes mellitus (β = 0.165, P = 0.003) and serum calcium (β = -0.135, P = 0.019) were significant determinant factors for systolic blood pressure. This study is the first to demonstrate that serum irisin levels are significantly negatively associated with blood pressure in dialysis patients. Further studies are needed to provide possible mechanisms. We demonstrated that serum irisin levels were negatively associated with blood pressure in dialysis patients, which may provide a new target for antihypertensive treatment.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Diagnosis and treatment of hypertension in dialysis patients: a systematic review

In patients with end-stage renal disease (ESRD) undergoing dialysis, hypertension is common but often inadequately controlled. The prevalence of hypertension varies widely among studies because of differences in the definition of hypertension and the methods of used to measure blood pressure (BP), i.e., peri-dialysis or ambulatory BP monitoring (ABPM). Recently, ABPM has become the gold standard for diagnosing hypertension in dialysis patients. Home BP monitoring can also be a good alternative to ABPM, emphasizing BP measurement outside the hemodialysis (HD) unit. One thing for sure is pre- and post-dialysis BP measurements should not be used alone to diagnose and manage hypertension in dialysis patients. The exact target of BP and the relationship between BP and all-cause mortality or cause-specific mortality are unclear in this population. Many observational studies with HD cohorts have almost universally reported a U-shaped or even an L-shaped association between BP and all-cause mortality, but most of these data are based on the BP measured in HD units. Some data with ABPM have shown a linear association between BP and mortality even in HD patients, similar to the general population. Supporting this, the results of meta-analysis have shown a clear benefit of BP reduction in HD patients. Therefore, further research is needed to determine the optimal target BP in the dialysis population, and for now, an individualized approach is appropriate, with particular emphasis on avoiding excessively low BP. Maintaining euvolemia is of paramount importance for BP control in dialysis patients. Patient heterogeneity and the lack of comparative evidence preclude the recommendation of one class of medication over another for all patients. Recently, however, β-blockers could be considered as a first-line therapy in dialysis patients, as they can reduce sympathetic overactivity and left ventricular hypertrophy, which contribute to the high incidence of arrhythmias and sudden cardiac death. Several studies with mineralocorticoid receptor antagonists have also reported promising results in reducing mortality in dialysis patients. However, safety issues such as hyperkalemia or hypotension should be further evaluated before their use.

Prevalence of Apparent Treatment-Resistant Hypertension in ESKD Patients Receiving Peritoneal Dialysis

BACKGROUND

Apparent treatment-resistant hypertension (aTRH) is defined as failure to achieve adequate blood pressure (BP) control despite taking ≥3 antihypertensive medications from different categories or when taking ≥4 antihypertensives regardless of BP levels.

METHODS

In this cross-sectional study, we estimated the prevalence of aTRH in 140 patients receiving long-term peritoneal dialysis (PD) in four centers of Northern Greece, using the "gold-standard" method of ambulatory BP monitoring for the assessment of BP control status. The presence of subclinical overhydration was evaluated with the method of bioimpedance spectroscopy (BIS).

RESULTS

Incorporating the diagnostic threshold of 130/80 mmHg for 24-hour ambulatory BP, the prevalence of aTRH in the overall study population was 30%. Compared to patients without aTRH, those with aTRH tended to be older in age, had higher PD vintage, had higher dialysate-to-plasma creatinine ratio, had more commonly history of diabetes mellitus, and were more commonly current smokers. With respect to the volume status, the overhydration index in BIS was higher in those with versus without aTRH (2.0 ± 1.9 L vs. 1.1 ± 2.0 L, P < 0.05). The prevalence of volume overload, defined as an overhydration index in BIS > 2.5 L, was also higher in the subgroup of patients with aTRH (38.1% vs. 18.4, P = 0.01).

CONCLUSION

The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population.The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population.

CLINICAL TRIALS REGISTRATION

Trial Number NCT03607747.

Epidemiology of peritoneal dialysis outcomes

Peritoneal dialysis (PD) is an important home-based treatment for kidney failure and accounts for 11% of all dialysis and 9% of all kidney replacement therapy globally. Although PD is available in 81% of countries, this provision ranges from 96% in high-income countries to 32% in low-income countries. Compared with haemodialysis, PD has numerous potential advantages, including a simpler technique, greater feasibility of use in remote communities, generally lower cost, lesser need for trained staff, fewer management challenges during natural disasters, possibly better survival in the first few years, greater ability to travel, fewer dietary restrictions, better preservation of residual kidney function, greater treatment satisfaction, better quality of life, better outcomes following subsequent kidney transplantation, delayed need for vascular access (especially in small children), reduced need for erythropoiesis-stimulating agents, and lower risk of blood-borne virus infections and of SARS-CoV-2 infection. PD outcomes have been improving over time but with great variability, driven by individual and system-level inequities and by centre effects; this variation is exacerbated by a lack of standardized outcome definitions. Potential strategies for outcome improvement include enhanced standardization, monitoring and reporting of PD outcomes, and the implementation of continuous quality improvement programmes and of PD-specific interventions, such as incremental PD, the use of biocompatible PD solutions and remote PD monitoring.

The use of peritoneal dialysis (PD) can be advantageous compared with haemodialysis treatment, although several barriers limit its broad implementation. This review examines the epidemiology of peritoneal dialysis (PD) outcomes, including clinical, patient-reported and surrogate PD outcomes.

Peritoneal dialysis (PD) has distinct advantages compared with haemodialysis, including the convenience of home treatment, improved quality of life, technical simplicity, lesser need for trained staff, greater cost-effectiveness in most countries, improved equity of access to dialysis in resource-limited settings, and improved survival, particularly in the first few years of initiating therapy.

Important barriers can hamper PD utilization in low-income settings, including the high costs of PD fluids (owing to the inability to manufacture them locally and the exorbitant costs of their import), limited workforce availability and a practice culture that limits optimal PD use, often leading to suboptimal outcomes.

PD outcomes are highly variable around the world owing in part to the use of variable outcome definitions, a heterogeneous practice culture, the lack of standardized monitoring and reporting of quality indicators, and kidney failure care gaps (including health care workforce shortages, inadequate health care financing, suboptimal governance and a lack of good health care information systems).

Key outcomes include not only clinical outcomes (typically defined as medical outcomes based on clinician assessment or diagnosis) — for example, PD-related infections, technique survival, mechanical complications, hospitalizations and PD-related mortality — but also patient-reported outcomes. These outcomes are directly reported by patients and focus on how they function or feel, typically in relation to quality of life or symptoms; patient-reported outcomes are used less frequently than clinical outcomes in day-to-day routine care.

Cardiovascular Effects of Home Dialysis Therapies: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage kidney disease. Currently, thrice-weekly in-center hemodialysis for 3 to 5 hours per session is the most common therapy worldwide for patients with treated kidney failure. Outcomes with thrice-weekly in-center hemodialysis are poor. Emerging evidence supports the overarching hypothesis that a more physiological approach to administering dialysis therapy, including in the home through home hemodialysis or peritoneal dialysis, may lead to improvement in several cardiovascular risk factors and cardiovascular outcomes compared with thrice-weekly in-center hemodialysis. The Advancing American Kidney Health Initiative, which has a goal of increasing the use of home dialysis, is aligned with the American Heart Association's 2024 mission to champion a full and healthy life and health equity. We conclude that incorporation of interdisciplinary care models to increase the use of home dialysis therapies in an equitable manner will contribute to the ultimate goal of improving outcomes for patients with kidney failure and cardiovascular disease.

Plant-Based Diets and Peritoneal Dialysis: A Review

Whole food plant-based diets are gaining popularity as a preventative and therapeutic modality for numerous chronic health conditions, including chronic kidney disease, but their role and safety in end-stage kidney disease patients on peritoneal dialysis (PD) is unclear. Given the general public’s increased interest in this dietary pattern, it is likely that clinicians will encounter individuals on PD who are either consuming, considering, or interested in learning more about a diet with more plants. This review explores how increasing plant consumption might affect those on PD, encompassing potential benefits, including some specific to the PD population, and potential concerns.

Current apparent treatment-resistant hypertension in patients undergoing peritoneal dialysis: A multi-center cross-sectional study

Apparent treatment‐resistant hypertension (aTRH) is the most commonly used term to report resistant hypertension (RH) and is considered as a common problem in dialysis population. However, few reports have focused on peritoneal dialysis (PD) hypertensive patients. The authors conducted a multi‐center cross‐sectional study involving 1789 PD patients from nine centers in Guangdong, China. The prevalence of aTRH was estimated by home blood pressure (BP) monitoring. Evaluating drug adherence through Eight‐item Morisky Medication Adherence Scale (MMAS‐8) and pill counting was performed to assess RH in one PD center. Related factors of aTRH were analyzed using logistic regression analysis. The prevalence of aTRH in PD patients was estimated at 42.2% (755 out of 1789 hypertensive patients) based on home BP. Of those, 91.4% patients were classified as uncontrolled RH, 2.0% as controlled RH, and 6.6% as refractory hypertension. The prevalence of RH was 40.6% and 41.9% among those with medium/high adherence based on the MMAS‐8 scores and the pill counting rate, respectively. PD patients who were younger, with higher body mass index, with lower serum albumin and poorer dialysis adequacy were significantly associated with higher aTRH incident. In conclusion, the present study demonstrates a high prevalence of aTRH in PD population, which occurs in about two in five treated hypertensive patients. Nutritional status and dialysis adequacy might tightly associate with aTRH.

Peritoneal-Membrane Characteristics and Hypervolemia Management in Peritoneal Dialysis: A Randomized Control Trial

Excessive bodily-fluid retention is the major cause of hypertension and congestive heart failure in patients with end-stage renal disease. Compared to hemodialysis, peritoneal dialysis (PD) uses the abdominal peritoneum as a semipermeable dialysis membrane, providing continuous therapy as natural kidneys, and having fewer hemodynamic changes. One major challenge of PD treatment is to determine the dry weight, especially considering that the speed of small solutes and fluid across the peritoneal membrane varies among individuals; considerable between-patient variability is expected in both solute transportation and ultrafiltration capacity. This study explores the influence of peritoneal-membrane characteristics in the hydration status in patients on PD. A randomized control trial compares the bioimpedance-assessed dry weight with clinical judgment alone. A high peritoneal membrane D/P ratio was associated with the extracellular/total body water ratio, dialysate protein loss, and poor nutritional status in patients on PD. After a six-month intervention, patients with monthly bioimpedance analysis (BIA) assistance had better fluid (−1.2 ± 0.4 vs. 0.1 ± 0.4 kg, p = 0.014) and blood-pressure (124.7 ± 2.7 vs. 136.8 ± 2.8 mmHg, p < 0.001) control; however, hydration status and blood pressure returned to the baseline after we prolonged BIA assistance to a 3-month interval. The dry-weight reduction process had no negative effect on residual renal function or peritoneal-membrane function. We concluded that peritoneal-membrane characteristics affect fluid and nutritional status in patients on PD, and BIA is a helpful objective technique for fluid assessment for PD.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

The associations of blood pressure parameters with all-cause and cardiovascular mortality in peritoneal dialysis patients: a cohort study in China

BACKGROUND

It remains controversial to claim blood pressure (BP) as a leading risk factor for high risk of death in peritoneal dialysis patients, and less is known about the relationship between BP and mortality in Chinese peritoneal dialysis patients.

METHODS

From Zhejiang Renal Data System in China, we collected data on patients treated and followed up at 98 peritoneal dialysis centres from 2008 to 2016. The associations of BP parameters [SBP, DBP, mean arterial pressure (MAP) and pulse pressure (PP)] with all-cause and cardiovascular mortality were examined. We fitted Cox models for mortality with penalized splines using nonparametric smoothers. Several sensitivity analyses were performed to confirm the robustness of our primary findings.

RESULTS

A total of 7335 Chinese peritoneal dialysis patients were included. During a median follow-up of 35.8 months, 1281 (17.5%) patients died. SBP, DBP, MAP follow a U-shaped pattern of both all-cause and cardiovascular mortality. PP presents a reverse L-shaped association with all-cause mortality. Either a higher (SBP >141, DBP >85 or MAP >102 mmHg) or lower (SBP <119, DBP <67 or MAP <88 mmHg) BP tends to have a significantly higher all-cause and cardiovascular mortality risk. Higher PP (>60 mmHg) is related to a higher risk of all-cause mortality, but not cardiovascular mortality. These associations remain the same in our competing risk analysis and subgroup analyses.

CONCLUSION

These data indicate U-shaped associations of SBP, DBP and MAP with all-cause mortality and cardiovascular mortality, respectively, and a reverse L-shaped association of PP with all-cause mortality. Further studies are needed to reliably establish the optimal BP targets for better hypertension control in peritoneal dialysis patients.

Mild sodium reduction in peritoneal dialysis solution improves hypertension in end stage kidney disease: a case-report study

Introduction

Blood Pressure (BP) control is largely unsatisfied in End Stage Kidney Disease (ESKD) principally due to sodium retention. Peritoneal Dialysis (PD) is the most common type of home dialysis, using a peritoneal membrane to remove sodium, though sodium removal remains challenging.

Methods

This is a case-study reporting two consecutive ESKD patients treated by a novel peritoneal PD solution with a mildly reduced sodium content (130 mmol/L) to treat hypertension.

Results

In the first case, a 78-year-old woman treated by Continuous Ambulatory PD (CAPD) with standard solution (three 4 h-dwells per day 1.36% glucose 132 mmol/L) showed resistant hypertension confirmed by ambulatory blood pressure monitoring (ABPM), reporting 24 h-BP: 152/81 mmHg, day-BP:151/83 mmHg and night-ABP: 153/75 mmHg, with inversion of the circadian systolic BP rhythm (1.01), despite use of three anti-hypertensives and a diuretic at adequate doses. No sign of hypervolemia was evident. We then switched from standard PD to low-sodium solution in all daily dwells. A six-months low-sodium CAPD enabled us to reduce diurnal (134/75 mmHg) and nocturnal BP (122/67 mmHg), restoring the circadian BP rhythm, with no change in ultrafiltration or residual diuresis. Diet and drug prescription were unmodified too.

The second case was a 61-year-old woman in standard CAPD (three 5 h-dwells per day) suffering from hypertension confirmed by ABPM (mean 24 h-ABP: 139/84 mmHg; mean day-ABP:144/88 mmHg and mean night-ABP:124/70 mmHg). She was switched from 132-Na CAPD to 130-Na CAPD, not changing dialysis schedule. No fluid expansion was evident. During low-sodium CAPD, antihypertensive therapy (amlodipine 10 mg and Olmesartan 20 mg) has been reduced until complete suspension. After 6 months, we repeated ABPM showing a substantial reduction in mean 24 h-ABP (117/69 mmHg), mean diurnal ABP (119/75 mmHg) and mean nocturnal ABP (111/70 mmHg). Ultrafiltration and residual diuresis remained unmodified. No side effects were reported in either cases.

Conclusions

This case-report study suggests that mild low-sodium CAPD might reduce BP in hypertensive ESKD patients.

Association of Ambulatory Blood Pressure with All-Cause Mortality and Cardiovascular Outcomes in Peritoneal Dialysis Patients

BACKGROUND

Ambulatory blood pressure monitoring is the gold standard for the diagnosis of hypertension, but its effects on all-cause mortality and cardiovascular outcomes in peritoneal dialysis (PD) patients remain uncertain. We aimed to investigate the association between ambulatory blood pressure and clinical outcomes in PD patients.

METHODS

A prospective, observational cohort study was conducted in PD patients enrolled from March 2001 to July 2018 and followed until October 2019. Blood pressure was evaluated using 24-h ambulatory blood pressure monitoring. The endpoints included all-cause mortality, cardiovascular mortality, and cardiovascular events. Multivariable Cox regression was used to identify the associations between ambulatory blood pressure and endpoints. Subsequently, multivariable logistic regression was conducted to identify factors associated with elevated pulse pressure (PP).

RESULTS

A total of 260 PD patients (154 men, 59.2%) were recruited. The median follow-up duration was 40.7 months. Our studies revealed that PP was an independent predictor of all-cause mortality (hazard ratio [HR], 1.018; 95% CI, 1.001-1.034; p = 0.032), cardiovascular mortality (HR, 1.039; 95% CI, 1.017-1.061; p < 0.001), and cardiovascular events (HR, 1.028; 95% CI, 1.011-1.046; p = 0.001). Systolic blood pressure was an independent predictor of cardiovascular mortality (HR, 1.023; 95% CI, 1.007-1.040; p = 0.005) and cardiovascular events (HR, 1.018; 95% CI, 1.006-1.030; p = 0.003). Vascular calcification was significantly associated with elevated PP (OR, 3.069; 95% CI, 1.632-5.772; p = 0.001).

CONCLUSION

24-h ambulatory PP was the most significant predictor of all blood pressure indicators for clinical outcomes in PD patients.

Uncertainties in BP management in dialysis patients

Hypertension in dialysis patients is extremely common. In this article, we review the current evidence for blood pressure (BP) goals in hemodialysis patients, and consider the effectiveness of interventions by which BP may be lowered, including manipulation of dietary and dialysate sodium; optimization of extracellular water; prolongation of dialysis time; and antihypertensive medication. Although two meta-analyses suggest lowering BP using antihypertensive drugs might be beneficial in reducing cardiovascular events and mortality, there are insufficient rigorously designed trials in hypertensive hemodialysis populations to determine preferred antihypertensive drug classes. We suggest aiming for predialysis systolic BP between 130 and 159 mm Hg, while at the same time acknowledge the significant limitations of the data upon which it is based. We conclude by summarizing current knowledge as regards management of hypertension in the peritoneal dialysis population and make recommendations for future research in this field.

Importance of Blood Pressure and Volume Control in Peritoneal Dialysis Patients

Objectives

To review the factors that impact control of blood pressure and euvolemia in peritoneal dialysis patients.

Design

Review of the most recent publications on this subject; inclusion of some personal data on the relation between plasma volume and evolution of blood pressure in short-term and long-term peritoneal dialysis patients.

Setting

Peritoneal dialysis program in a university hospital.

Results

The literature on circadian blood pressure and the role of the decreased compliance of the great vessels in uremia is reviewed. Analysis of the long-term evolution of plasma volume in peritoneal dialysis patients in correlation with the evolution of blood pressure indicates a positive correlation in 36 of 46 simultaneous determinations. The treatment of volume overload and hypertension in peritoneal dialysis includes the prescription of loop diuretics, preservation of residual renal function, reduction of dietary salt intake, and prevention and treatment of peritoneal ultrafiltration failure.

Conclusions

A reduction in the great cardiovascular mortality in peritoneal dialysis patients as nowadays observed can only be expected when more attention is paid to better control of hypervolemia and hypertension in these patients.

Fluid Status, Blood Pressure, and Cardiovascular Abnormalities in Patients on Peritoneal Dialysis

♦ Objective

Hypertension, reduced arterial distensibility, and left ventricular hypertrophy (LVH) are risk factors for mortality in hemodialysis patients. However, few studies have focused on the relation between fluid status, blood pressure (BP), and cardiovascular abnormalities in peritoneal dialysis (PD) patients. This study was designed, first, to assess, using tracer dilution techniques, fluid status in PD patients compared to a control population of stable renal transplant (RTx) patients; second, to study the relation between fluid status, BP, and arterial wall abnormalities; third, to assess the determinants of cardiac structure; and last, to compare office and ambulatory BP measurements with respect to cardiac abnormalities.

♦ Design

Cross-sectional study.

♦ Setting

Multicenter study.

♦ Patients

41 stable PD patients with a mean Kt/V urea of 2.4 ± 0.7, and 77 stable RTx patients.

♦ Intervention

Fluid status was assessed by tracer dilution techniques: extracellular volume (ECV) with bromide dilution; total body water (TBW) with deuterium oxide; and plasma volume (PV) with dextran 70. Echocardiography was performed to assess left ventricular mass (LVM), left ventricular end diastolic diameter (LVEDD), and relative wall thickness as indicators of LVH. Echography of the common carotid artery was performed to assess arterial distensibility. Both office and 24-hour ambulatory BP measurements were performed.

♦ Results

Fluid status, as assessed by ECV corrected for body surface area (BSA) (ECV:BSA), was significantly different between PD and RTx patients (9.4 ± 2.6 vs 8.6 ± 1.2 L/m2, p < 0.05). In 36.6% of the PD patients, ECV:BSA was above the 90th percentile of the RTx patients. Fluid status corrected for BSA, assessed by TBW (TBW:BSA), ECV (ECV:BSA), or plasma volume (PV:BSA), was significantly related to diastolic BP (DBP) ( r = 0.35, r = 0.37, r = 0.53; p < 0.05). Arterial distensibility of the common carotid artery was related to systolic BP (SBP) ( r = –0.36, p < 0.05). ECV was significantly related to LVEDD ( r = 0.41, p < 0.05) as a marker of eccentric LVH, whereas arterial distensibility was related to relative wall thickness ( r = –0.53, p < 0.001) as a marker of concentric LVH. An abnormal day–night BP rhythm, which was not related to fluid status, was observed in 68.4% of patients. Ambulatory DBP and SBP but not office DBP and SBP were related to LVM ( r = 0.43, r = 0.46; p < 0.01).

♦ Conclusions

A large proportion of PD patients whose treatment prescriptions are in accordance with the Dialysis Outcomes Quality Initiative guidelines were found to be overhydrated compared with a population of stable RTx patients. Fluid status was significantly related to DBP and eccentric LVH, whereas arterial distensibility of the common carotid artery was significantly related to SBP and concentric LVH. In contrast to ambulatory BP, office BP was not related to LVM.

Blood Pressure, Volume, and Sodium Control in an Automated Peritoneal Dialysis Population

Objectives

To examine the control of blood pressure and volume, and the role of sodium removal in a single, large, contemporary, automated peritoneal dialysis (APD) population where icodextrin is used liberally and there is a policy to avoid long duration glucose-based daytime dwells.

Design

Observational cross-sectional study.

Setting

A university hospital.

Patients

56 APD patients, with a mean duration on peritoneal dialysis of 1.9 years; 50% were prescribed icodextrin.

Main Outcome Measures

Blood pressure, extracellular water volume (ECW)-to-intracellular water volume (ICW) ratio, and total (peritoneal and urinary) sodium removal.

Results

Sodium Removal: Mean total sodium removal, while low at 102.9 ± 64.6 mmol/day, showed a wide range, with 41% having a sodium removal of >120 mmol/day. Total sodium removal correlated with total body water, ECW, and ICW ( p < 0.001, p < 0.001, p < 0.025, respectively), as well as with height and weight ( p < 0.06, p < 0.01 respectively). On multivariate analysis, only ultra-filtration volume and urine volume were significantly associated with total sodium removal ( r2 = 0.67, p < 0.0001 for both). There was also a correlation between sodium removal and urea nitrogen appearance ( r2 = 0.31, p < 0.001), with urea nitrogen appearance in turn being closely correlated with ICW ( p < 0.001). Volume Status: The ECW/ICW ratio was 0.88 ± 0.17, which was not significantly different to that found in hemodialysis patients without clinical evidence of fluid overload, either predialysis (0.96 ± 0.16) or postdialysis (0.92 ± 0.16); p = 0.07 and 0.36 respectively. Blood Pressure: Mean ± standard deviation systolic blood pressure (BP) was 111.9 ± 18.2 mmHg and diastolic BP was 63.3 ± 11.9 mmHg, with only 4 (7%) patients having a systolic BP > 140 mmHg and 1 (2%) having a diastolic BP > 80 mmHg. Median number of antihypertensives was 1 per day. Blood pressure control and ECW/ICW ratio were similar in those with sodium removal >120 mmol/day compared to those with sodium removal ≤120 mmol/day ( p = 0.39 for SBP, p = 0.70 for diastolic B P, p = 0.24 for ECW/ICW).

Conclusions

We have shown that good blood pressure and volume control is achievable in a large contemporary APD population with liberal use of icodextrin and avoidance of long daytime glucose-based dwells. Neither low nor high sodium removal was associated with more frequent hypertension or volume expansion.

Fluid Status and its Management in Japanese Peritoneal Dialysis Patients

This article reviews published studies related to fluid status of Japanese peritoneal dialysis (PD) patients and its impact on technique and patient survival. In addition, some specifics related to clinical background that potentially influence fluid status are described. According to a multi-center survey conducted in Japan, nearly 25% of Japanese PD patients are overhydrated. Available data indicate that a high salt diet may conceivably play an important role in the pathogenesis of fluid overload in Japanese PD patients, and it in turn negatively impacts patient prognosis. Because of the generally adopted policy among Japanese PD experts to avoid regular use of 3.86% glucose solution, icodextrin solution is now used in more than one third of all patients. Other means of managing fluid overload, such as drug therapy, combination (complementary) therapy with hemodialysis, and low sodium PD solution, are also explored and summarized in this article.

Volume management as a key dimension of a high-quality PD prescription

BACKGROUND

Appropriate volume control is one of the key goals in a peritoneal dialysis (PD) prescription. As such it is an important component of the International Society of Peritoneal Dialysis (ISPD) guideline for "High-quality PD prescription" necessitating a review of the literature on volume management. The workgroup recognized the importance of including within its scope measures of volume status and blood pressure in prescribing high-quality PD therapy.

METHODS

A Medline and PubMed search for publications addressing volume status and its management in PD since the publication of the 2015 ISPD Adult Cardiovascular and Metabolic Guidelines, from October 2014 through to July 2019, was conducted.

RESULTS

There were no randomized controlled trials on blood pressure intervention and six randomized trials of bioimpedance-guided volume management. Generally, all studies were of small sample size, short duration, and used surrogate markers as primary outcomes. As a consequence, only "practice points" were drawn. High-quality goal-directed PD prescription should aim to achieve and maintain clinical euvolemia taking residual kidney function and its preservation into account, so that both fluid removal from peritoneal ultrafiltration and urine output are considered and residual kidney function is not compromised. Blood pressure should be included as a key objective parameter in assessing the quality of PD prescription but there is currently no evidence for a specific target in PD. Clinical examination remains the keystone of routine clinical care.

CONCLUSIONS

High-quality goal-directed PD prescription should include volume management as one of the key dimensions.

Factors associated with systolic hypertension in peritoneal dialysis patients

Background

Hypertension is common in peritoneal dialysis (PD) patients and associated with adverse outcomes. Besides solute clearance, PD convective clearance is used to control extracellular water (ECW) volume and sodium balance. Previous studies have reported on hypertension in PD patients treated with continuous ambulatory peritoneal dialysis (CAPD) using hypertonic glucose dialysates. However, increasing numbers of PD patients are now treated with automated peritoneal dialysis (APD) and icodextrin dialysates. As such, we wished to explore factors associated with systolic blood pressure (SBP) in a modern cohort to identify targets to improve blood pressure control in PD patients.

Methods

We retrospectively reviewed the results from PD patients attending for peritoneal membrane assessment who had corresponding bioimpedance ECW and brain natriuretic peptide (NT-proBNP) measurements.

Results

We studied 510 PD patients: 317 (72.2%) male, 216 (42.4%) diabetics, median age 59 (47–72) years, and 51% treated by APD with a day-time icodextrin exchange. Mean systolic blood pressure (SBP) was 140 ± 24.8 mmHg. SBP was independently associated with 4-hour dialysate to plasma creatinine ratio (β = 29.5 (95% confidence limits 11.4–47.5, p = 0.001), N-terminal brain natriuretic peptide [β = 11.9 (7.2–16.7), p < 0.001], and daily urine sodium excretion [β = 1.7 (1.0–2.3), p < 0.001].

Conclusion

In the era of APD cyclers and icodextrin, SBP is associated with increased NT-proBNP, a marker of ECW expansion, and faster peritoneal transport, a risk factor for a positive sodium balance, and increased urinary sodium suggestive of higher dietary sodium intake. Patients should be encouraged to restrict sodium intake and PD prescriptions targeted to control ECW to improve SBP control.

Clinic and Home Blood Pressure Monitoring for the Detection of Ambulatory Hypertension Among Patients on Peritoneal Dialysis

The International Society of Peritoneal Dialysis recommends that adequate blood pressure (BP) assessment among patients on peritoneal dialysis should at least include measurements performed once-weekly at home and at each visit at clinic. However, the quality of evidence to support this guidance is suboptimal. Using ambulatory daytime BP as reference standard, we explored the diagnostic performance of clinic and home BP recordings in a cohort of 81 stable patients receiving peritoneal dialysis. BP was recorded using 3 different methodologies: (1) triplicate automated clinic BP recordings after a 5-minute seated rest with the validated monitor HEM 705 CP (Omron Healthcare); (2) 1-week averaged home BP recorded with a validated automated monitor on awaking and at bedtime; and (3) ambulatory BP monitoring with the Mobil-O-Graph device (IEM, Germany). The area under the curve of receiver operating characteristic curves in detection of ambulatory daytime systolic BP (SBP) ≥135 mm Hg was similar for clinic [area under the curve, 0.859; 95% CI, 0.776-0.941] and home SBP (area under the curve, 0.895; 95% CI, 0.815-0.976). In Bland-Altman analysis, clinic SBP overestimated daytime ambulatory SBP by 5.02 mm Hg with 95% limits of agreement ranging from -17.92 to 27.96 mm Hg. Similarly, home SBP overestimated daytime ambulatory SBP by 4.23 mm Hg, again with wide 95% limits of agreement (-16.05 to 24.51 mm Hg). These results show that 1-week averaged home SBP is of at least similar accuracy with standardized clinic SBP in diagnosing hypertension confirmed by ambulatory BP monitoring among patients on peritoneal dialysis.

Residual Renal Function and Effect of Low-Sodium Solution on Blood Pressure in Peritoneal Dialysis Patients

Background:Residual renal function (RRF) affects sodium and fluid balance. The aim of this analysis was to examine the impact of RRF on the effect of a sodium-reduced peritoneal dialysis fluid (PDF) on blood pressure (BP).Methods:This is a post-hoc analysis of a prospective, randomized, controlled double-blind clinical trial with 82 patients on continuous ambulatory PD (CAPD) treated with a low-sodium (125 mmol/L Na) or a standard-sodium (134 mmol/L Na) PDF. Subgroups according to glomerular filtration rate (GFR) at baseline (≤ / > 6 mL/min/1.73 m²) were analyzed for BP and antihypertensive medication.Results:In the low-GFR group on low-sodium PDF (N = 26), systolic BP was reduced from 152 ± 24 mmHg at baseline to 137 ± 21 mmHg at week 12, diastolic BP from 90 ± 16 mmHg to 83 ± 11 mmHg. In the low-GFR group on standard-sodium PDF and in the high-GFR group on both PDF types, only minor changes were observed. For the low-GFR subgroup, the confounder-adjusted mean study group difference in systolic BP at week 12 between low-sodium and standard-sodium PDF was -16.9 (95% confidence interval [CI] -27.2 to -6.6) mmHg, for diastolic BP, it was -7.0 (95% CI -12.6 to -1.4) mmHg. In both GFR subgroups, more patients had a reduced daily dose of antihypertensive medication and fewer patients an increased daily dose in the low-sodium compared with the standard-sodium group at week 12.Conclusions:The reduction of BP with a sodium-reduced PDF seems to be more effective in patients with no or low RRF than in patients with residual capacity of renal sodium and fluid control.

Assessment and Management of Hypertension among Patients on Peritoneal Dialysis

Approximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and the absence of acute shifts in pressure and volume parameters is an important differentiation between PD and in-center hemodialysis. However, the burden of hypertension and prognostic association of BP with mortality follow comparable patterns in both modalities. Although management of hypertension uses similar therapeutic principles, long-term preservation of residual diuresis and longevity of peritoneal membrane function require particular attention in the prescription of the appropriate dialysis regimen among those on PD. Dietary sodium restriction, appropriate use of icodextrin, and limited exposure of peritoneal membrane to bioincompatible solutions, as well as adaptation of the PD regimen to the peritoneal transport characteristics, are first-line therapeutic strategies to achieve adequate volume control with a potential long-term benefit on technique survival. Antihypertensive drug therapy is a second-line therapeutic approach, used when BP remains unresponsive to the above volume management strategies. In this article, we review the available evidence on epidemiology, diagnosis, and treatment of hypertension among patients on PD and discuss similarities and differences between PD and in-center hemodialysis. We conclude with a call for randomized trials aiming to elucidate several areas of uncertainty in management of hypertension in the PD population.

Clinical Studies of Interventions to Mitigate Cardiovascular Risk in Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is highly prevalent in the peritoneal dialysis (PD) population, affecting up to 60% of cohorts. CVD is the primary cause of death in up to 40% of PD patients in Australia, New Zealand, and the United States. Cardiovascular mortality rates are reported to be approximately 14 per 100 patient-years, which are 10- to 20-fold greater than those of age- and sex-matched controls. The excess risk of CVD is related to a combination of traditional risk factors (such as hypertension, dyslipidemia, obesity, smoking, sedentary lifestyle, and insulin resistance), nontraditional (kidney disease-related) risk factors (such as anemia, chronic volume overload, inflammation, malnutrition, hyperuricemia, and mineral and bone disorder), and PD-specific risk factors (such as dialysis solutions, glycation end products, hypokalemia, residual kidney function, and ultrafiltration failure). Interventions targeting these factors may mitigate cardiovascular risk, although high-level clinical evidence is lacking. This review summarizes the evidence relating to cardiovascular interventions targeting modifiable CVD risk factors in PD patients, as well as highlighting the key recommendations of the International Society for Peritoneal Dialysis Cardiovascular and Metabolic Guidelines.

Hypertension in patients on dialysis: diagnosis, mechanisms, and management

Hypertension (blood pressure > 140/90 mm Hg) is very common in patients undergoing regular dialysis, with a prevalence of 70-80%, and only the minority has adequate blood pressure (BP) control. In contrast to the unclear association of predialytic BP recordings with cardiovascular mortality, prospective studies showed that interdialytic BP, recorded as home BP or by ambulatory blood pressure monitoring in hemodialysis patients, associates more closely with mortality and cardiovascular events. Although BP is measured frequently in the dialysis treatment environment, aspects related to the measurement technique traditionally employed may be unsatisfactory. Several other tools are now available and being used in clinical trials and in clinical practice to evaluate and treat elevated BP in chronic kidney disease (CKD) patients. While we wait for the ongoing review of the CKD Blood Pressure KIDGO guidelines, there is no guideline for the dialysis population addressing this important issue. Thus, the objective of this review is to provide a critical analysis of the information available on the epidemiology, pathogenic mechanisms, and the main pillars involved in the management of blood pressure in stage 5-D CKD, based on current knowledge.

Patient-Centered Approach for Hypertension Management in End-Stage Kidney Disease: Art or Science?

Hypertension is present in most patients with end-stage kidney disease initiating dialysis and management of hypertension is a routine but challenging task in everyday dialysis care. End-stage kidney disease patients are uniquely heterogeneous individuals with significant variations in demographic characteristics, functional capacity, and presence of concomitant comorbid conditions and their severity. Therefore, these patients require personalized approaches in addressing not only hypertension but related illnesses, while also accounting for overall prognosis and projected longevity. There are only limited clinical trial data to guide individualized blood pressure management and current guidelines are based predominantly on observational evidence and expert opinions. Inthis review, we reflect on the shortcomings of peridialytic blood pressure recordings and discuss an important paradigm shift toward using out-of-dialysis blood pressure for evaluating hypertension control and for making treatment decisions. In addition, we provide our personal view on blood pressure goals and summarize nonpharmacologic and pharmacologic treatment options for individualized management of hypertension in end-stage kidney disease.

Clinical management of patients on peritoneal dialysis in Italy: results from the ATENA study

BACKGROUND

In Italy, few studies have examined the clinical management of peritoneal dialysis (PD) patients, resulting in a lack of information and awareness.

METHODS

A total of 378 PD patients (64.7 ± 14.3 years, 58.9% males) were enrolled across 15 centres in a 12-month retrospective and 6-month prospective study. The primary objective was to evaluate the achievement of Kidney Disease Outcomes Quality Initiative and Kidney Disease Improving Global Outcomes guidelines on recommended target values for anaemia, high blood pressure and mineral metabolism. Comorbidities, hospitalizations, treatment and quality of life were also assessed.

RESULTS

Frequent comorbidities included hypertension (87.8%) and cardiovascular disease (39.7%). Peritonitis was the leading cause of hospitalization [12 admissions per 100 person-years (95% confidence interval 9.3-15.2)]. At 6 months, anaemia corrected by erythropoiesis-stimulating agents was observed in 30% of patients and 73% received erythropoiesis-stimulating agents. Systolic and diastolic blood pressures were recorded in 50% and 20% of patients, respectively. Sixty-four percent of echocardiograms revealed left ventricular hypertrophy and 30% of patients had vitamin D <10 ng/mL. Medication to treat intact parathyroid hormone (PTH) included calcitriol (36.3%), paricalcitol (29.2%), cholecalciferol (23.6%) and cinacalcet (21.5%). In a subgroup of patients matched for baseline PTH treated for 1 year, a significant reduction in PTH with paricalcitol (-41%; P < 0.001) but not cinacalcet (+2%; P = 0.63) was observed. Comparison of quality of life domains revealed significant differences for symptoms (P = 0.049), cognitive function (P = 0.019) and social support (P = 0.04) (baseline versus 6 months).

CONCLUSIONS

Hypertension and cardiovascular diseases were frequent comorbidities and peritonitis was the leading cause of hospitalization. Secondary hyperparathyroidism and anaemia were common, thus necessitating frequent monitoring of PTH, calcium, phosphorus and haemoglobin.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease treated with hemodialysis or peritoneal dialysis, hypertension is very common and often poorly controlled. Blood pressure (BP) recordings obtained before or after hemodialysis display a J-shaped or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar hemodynamic setting related with dialysis treatment. Elevated BP by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnea and the use of erythropoietin-stimulating agents may also be involved. Nonpharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium-volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease (ESRD) treated with haemodialysis or peritoneal dialysis, hypertension is common and often poorly controlled. Blood pressure (BP) recordings obtained before or after haemodialysis display a J- or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar haemodynamic setting related to dialysis treatment. Elevated BP detected by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnoea and the use of erythropoietin-stimulating agents may also be involved. Non-pharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium and volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

Comparison of the risk of non-traumatic lower extremity amputation between haemodialysis and peritoneal dialysis patients with end-stage renal disease

AIM

We used insurance claims data of Taiwan to compare the risk of non-traumatic lower extremity amputation between haemodialysis (HD) and peritoneal dialysis (PD) patients.

METHODS

We identified 77 669 HD patients and 10 035 PD patients without prior amputation from 2000 to 2010. Incidence rates and hazard ratios (HRs) of lower extremity amputation, and subsequent 30-day mortality after amputation were evaluated up to 31 December 2011.

RESULTS

There were 2427 and 216 patients undergoing lower extremity amputation during follow-up in the HD and PD groups with incidence rates of 8.35 and 5.79 per 1000 person-years, respectively. Compared with the HD group, the overall adjusted HR of lower extremity amputation for the PD group was 1.27 (95% CI = 1.10-1.46). The impact of diabetes status on the risk of lower extremity amputation interacted with dialysis modality significantly (P < 0.001). Compared with the corresponding HD patients, the PD patients with diabetes had an adjusted HR of 1.44 (95% CI = 1.24-1.67) for amputation, whereas those without diabetes had an adjusted HR of 0.58 (95% CI = 0.36-0.95). The subsequent 30-day mortality rates after amputation were not significantly different between the HD and PD groups (8.45% vs. 9.72%) with an adjusted odds ratio of 1.41 (95% CI = 0.87-2.28, PD versus HD).

CONCLUSION

Compared with corresponding HD patients, the amputation risk is higher for PD patients with diabetes, while the risk is lower for PD patients without diabetes. Dialysis patients have a high 30-day mortality risk after amputation.

Permanent cardiac pacing in patients with end-stage renal disease undergoing dialysis

BACKGROUND

Studies investigating the risk of cardiac dysrhythmia warranting permanent pacemaker therapy for end-stage renal disease (ESRD) patients are limited. This study investigated the incidence rate of permanent cardiac pacing in dialysis patients.

METHODS

Using the Taiwan National Health Insurance Database, we identified 28 471 newly diagnosed ESRD patients in 2000-2010 [9700 on peritoneal dialysis (PD) and 18 771 on hemodialysis (HD)] and 113 769 randomly selected controls without kidney disease, frequency-matched by sex, age and diagnosis date. We also established propensity score-matched HD and PD cohorts with 9700 patients each. Incidence rates and hazard ratios (HRs) of implantation were evaluated by the end of 2011. Complications were also evaluated among patients with implantation.

RESULTS

The incidence rates of permanent pacemaker implantation were 5.93- and 3.50-fold greater in HD and PD patients than in controls (1.44 and 0.85 versus 0.24 per 1000 person-years, respectively). The adjusted HRs (aHRs) of implantation were 3.26 [95% confidence interval (CI) = 2.41-4.42] and 2.36 (95% CI = 1.56-3.58) for HD and PD patients, respectively, compared with controls. The pacemaker implantation rate was 0.33 per 1000 person-years greater in the propensity score-matched HD cohort than in the PD cohort, with an aHR of 1.30 (95% CI = 0.82-2.05) for the HD cohort compared with the PD cohort.

CONCLUSIONS

Dialysis patients are at an increased risk of dysrhythmia requiring pacemaker implantation compared with the general population. The risks are not significantly different between HD and PD patients.

Impact of dialysis modality on the survival of patients with end-stage renal disease and prior stroke

PURPOSE

Of patients with end-stage renal disease (ESRD), 8-16 % had a history of stroke at dialysis initiation. We used the National Health Insurance Research Database of Taiwan to evaluate whether peritoneal dialysis (PD) or hemodialysis (HD) confers a survival advantage for patients with incident ESRD and prior stroke.

METHODS

We identified 975 patients undergoing PD and 975 propensity score-matched patients with newly diagnosed ESRD and prior stroke undergoing HD between 2000 and 2010. Both cohorts were followed up until the end of 2011. Comparisons of the risks of mortality between PD and HD were analyzed using the Cox proportional hazards regression model.

RESULTS

In the propensity score-matched cohorts, there was a 2.4 per 100 person-years greater mortality in patients with PD (20.4 vs. 18.0 per 100 person-years) with an adjusted hazard ratio (HR) of 1.20 (95 % CI 1.06-1.36). For patients with diabetes, ESRD and prior stroke, patients undergoing PD had inferior survival compared with those undergoing HD (adjusted HR 1.22, 95 % CI 1.05-1.43), particularly among female patients (adjusted HR 1.55, 95 % CI 1.25-1.91). For patients with ESRD and prior stroke but without diabetes, there was no significant difference in mortality between PD and HD (adjusted HR 1.20, 95 % CI 0.96-1.50).

CONCLUSIONS

PD was associated with overall poorer survival among patients with diabetes, ESRD and prior stroke and with similar overall survival among patients with ESRD and prior stroke, but without diabetes, compared with HD.

The Effect of Fluid Overload on Clinical Outcome in Southern Chinese Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

♦

BACKGROUND

Fluid overload is frequently present in dialysis patients and one of the important predictors of patient outcome. This study aimed to investigate the influence of fluid overload on all-cause mortality and technique failure in Southern Chinese continuous ambulatory peritoneal dialysis (CAPD) patients. ♦

METHODS

This was a post hoc study from a cross-sectional survey originally designed to investigate the prevalence and associated risk factors of fluid overload defined by bioimpedance analysis (BIA) in CAPD patients from January 1, 2008, to December 31, 2009. All 307 CAPD patients completing the original study were followed up until December 31, 2012. ♦

RESULTS

With a median follow-up period of 38.4 (19.2 - 47.9) months, 52 patients died. Patients with fluid overload (defined by extracellular water/total body water [ECW/TBW] ≥ 0.40) had a significantly higher peritonitis rate (0.016 vs 0.011 events/month exposure, p = 0.018) and cerebrovascular event rate (3.9 vs 1.1 events/100 patient years, p = 0.024) than the normal hydrated patients. Moreover, the results showed a significant rising of all-cause mortality (log-rank test = 5.59, p = 0.018), and a trend of increasing cardiovascular disease (CVD) mortality (log-rank test = 2.90, p = 0.089) and technique failure (log-rank test = 3.78, p = 0.052) in the patients with fluid overload. Fluid overload independently predicted all-cause mortality (hazard ratio [HR] = 12.98, 95%, confidence interval [CI] = 1.06 - 168.23, p = 0.042) and technique failure (HR = 13.56, 95% CI = 2.53 - 78.69, p = 0.007) in CAPD patients after adjustment for confounders. ♦

CONCLUSIONS

Fluid overload defined by BIA was an independent predictor for all-cause mortality and technique failure in CAPD patients. Continuous ambulatory peritoneal dialysis patients with fluid overload had a higher peritonitis rate, cardiovascular event rate, and poorer clinical outcome than those patients with normal hydration.

ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part I - Assessment and Management of Various Cardiovascular Risk Factors

Cardiovascular disease contributes significantly to the adverse clinical outcomes of peritoneal dialysis (PD) patients. Numerous cardiovascular risk factors play important roles in the development of various cardiovascular complications. Of these, loss of residual renal function is regarded as one of the key cardiovascular risk factors and is associated with an increased mortality and cardiovascular death. It is also recognized that PD solutions may incur significant adverse metabolic effects in PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendations regarding lifestyle modification, assessment and management of various cardiovascular risk factors, as well as management of the various cardiovascular complications including coronary artery disease, heart failure, arrhythmia (specifically atrial fibrillation), cerebrovascular disease, peripheral arterial disease and sudden cardiac death, to be published in 2 guideline documents. This publication forms the first part of the guideline documents and includes recommendations on assessment and management of various cardiovascular risk factors. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. The ISPD workgroup also identifies areas where evidence is lacking and further research is needed.

Left ventricular hypertrophy and blood pressure control in automated and continuous ambulatory peritoneal dialysis patients

Hypertension, non-dipper blood pressure (BP) pattern and decrease in daily urine output have been associated with left ventricular hypertrophy (LVH) in peritoneal dialysis (PD) patients. However, there is lack of data regarding the impact of different PD regimens on these factors. We aimed to investigate the impact of circadian rhythm of BP on LVH in end-stage renal disease patients using automated peritoneal dialysis (APD) or continuous ambulatory peritoneal dialysis (CAPD) modalities. Twenty APD (7 men, 13 women) and 28 CAPD (16 men, 12 women) patients were included into the study. 24-h ambulatory blood pressure monitoring (ABPM) and transthoracic echocardiography besides routine blood examinations were performed. Two groups were compared with each other for ABPM measurements, BP loads, dipping patterns, left ventricular mass index (LVMI) and daily urine output. Mean systolic and diastolic BP measurements, BP loads, LVMI, residual renal function (RRF) and percentage of non-dippers were found to be similar for the two groups. There were positive correlations of LVMI with BP measurements and BP loads. LVMI was found to be significantly higher in diastolic non-dippers compared to dippers (140.4 ± 35.3 vs 114.5 ± 29.7, respectively, P = 0.02). RRF and BP were found to be independent predictors of LVMI. Non-dipping BP pattern was a frequent finding among all PD patients without an inter-group difference. Additionally, higher BP measurements, decrease in daily urine output and non-dipper diastolic BP pattern were associated with LVMI. In order to avoid LVH, besides correction of anemia and volume control, circadian BP variability and diastolic dipping should also be taken into consideration in PD patients.

Control of fluid balance guided by body composition monitoring in patients on peritoneal dialysis (COMPASS): study protocol for a randomized controlled trial

Background

The clinical benefits of bioimpedance spectroscopy (BIS)-guided fluid management in patients on hemodialysis have been widely demonstrated. However, no previous reports have evaluated the effect of regular and serial BIS-guided fluid management on the residual renal function (RRF) in patients on peritoneal dialysis (PD). Therefore, we will evaluate the clinical efficacy of BIS-guided fluid management for preserving RRF and protecting cardiovascular events in patients on PD.

Methods/design

This is a multicenter, prospective, randomized controlled trial. A total of 138 participants on PD will be enrolled and randomly assigned to receive either BIS-guided fluid management or fluid management based only on the clinical information for 1 year. The primary outcome is the change in the glomerular filtration rate (GFR) between months 0 and 12 after starting treatment. The secondary outcomes will include GFR at month 12, time to the anuric state (urine volume <100 ml/day), and fatal and nonfatal cardiovascular events during treatment.

Discussion

This is the first clinical trial to investigate the effect of BIS-guided fluid management on RRF and for protecting against cardiovascular events in patients on PD.

Trial registration

Clinical Trials.gov number NCT01887262, June 24, 2013.

Assessment and management of hypertension in patients on dialysis

Hypertension is common, difficult to diagnose, and poorly controlled among patients with ESRD. However, controversy surrounds the diagnosis and treatment of hypertension. Here, we describe the diagnosis, epidemiology, and management of hypertension in dialysis patients, and examine the data sparking debate over appropriate methods for diagnosing and treating hypertension. Furthermore, we consider the issues uniquely related to hypertension in pediatric dialysis patients. Future clinical trials designed to clarify the controversial results discussed here should lead to the implementation of diagnostic and therapeutic techniques that improve long-term cardiovascular outcomes in patients with ESRD.