The association between BP and mortality in patients on chronic peritoneal dialysis

Delivering Personalized, Goal-Directed Care to Older Patients Receiving Peritoneal Dialysis

Background

An aging population living with chronic kidney disease and progressing to kidney failure, subsequently receiving peritoneal dialysis (PD) is growing. A significant proportion of these patients are also living with multi-morbidities and some degree of frailty. Recent practice recommendations from the International Society of Peritoneal Dialysis advocate for high-quality, goal-directed PD prescription, and the Standardized Outcomes of Nephrology-PD initiative emphasized the need for an individualized, goal-based care approach in all patients receiving PD treatment. In older patients, this approach to PD care is even more important. A frailty screening assessment, followed by a comprehensive geriatric assessment (CGA) prior to PD initiation and when dictated by change in relevant circumstances is paramount in tailoring PD care and prescription according to the needs, life goals, as well as clinical status of older patients with kidney failure.

Summary

Our review aimed to summarize the different dimensions to be taken into account when delivering PD care to the older patient - from frailty screening and CGA in older patients receiving PD to employing a personalized, goal-directed PD prescription strategy, to preserving residual kidney function, optimizing blood pressure (BP) control, and managing anemia, to addressing symptom burden, to managing nutritional intake and promoting physical exercise, and to explore telehealth opportunities for the older PD population.

Key Messages

What matters most to older PD patients may not be simply extending survival, but more importantly, to be living comfortably on PD treatment with minimal symptom burden in a home environment and to minimize treatment complications.

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.

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.

Management of hypertension and renin-angiotensin-aldosterone system blockade in adults with diabetic kidney disease: Association of British Clinical Diabetologists and the Renal Association UK guideline update 2021

People with type 1 and type 2 diabetes are at risk of developing progressive chronic kidney disease (CKD) and end-stage kidney failure. Hypertension is a major, reversible risk factor in people with diabetes for development of albuminuria, impaired kidney function, end-stage kidney disease and cardiovascular disease. Blood pressure control has been shown to be beneficial in people with diabetes in slowing progression of kidney disease and reducing cardiovascular events. However, randomised controlled trial evidence differs in type 1 and type 2 diabetes and different stages of CKD in terms of target blood pressure. Activation of the renin-angiotensin-aldosterone system (RAAS) is an important mechanism for the development and progression of CKD and cardiovascular disease. Randomised trials demonstrate that RAAS blockade is effective in preventing/ slowing progression of CKD and reducing cardiovascular events in people with type 1 and type 2 diabetes, albeit differently according to the stage of CKD. Emerging therapy with sodium glucose cotransporter-2 (SGLT-2) inhibitors, non-steroidal selective mineralocorticoid antagonists and endothelin-A receptor antagonists have been shown in randomised trials to lower blood pressure and further reduce the risk of progression of CKD and cardiovascular disease in people with type 2 diabetes. This guideline reviews the current evidence and makes recommendations about blood pressure control and the use of RAAS-blocking agents in different stages of CKD in people with both type 1 and type 2 diabetes.

The utility of remote patient management in peritoneal dialysis

Remote patient management (RPM) programs are one of the most crucial innovations in the peritoneal dialysis (PD) field that have been developed in the last decade. RPM programs are associated with favourable clinical outcomes by increasing the adherence of the patients to PD prescription. The literature supports that RPM is associated with increased blood pressure control and technique survival, and decreased hospitalization rate, length of hospital stay and health costs. RPM programs also facilitate patient follow-up during the coronavirus disease 2019 pandemic, increase treatment adherence and lead to better clinical outcomes. However, published data remain scarce and mainly consist of observational or retrospective studies with relatively low numbers of patients. Therefore, randomized controlled trial results will be more informative to demonstrate the effect of RPM programs on clinical outcomes.

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.

Association of blood pressure after peritoneal dialysis initiation with the decline rate of residual kidney function in newly-initiated peritoneal dialysis patients

Background

Lower blood pressure (BP) levels are linked to a slower decline of kidney function in patients with chronic kidney disease (CKD) without kidney replacement therapy. However, there are limited data on this relation in peritoneal dialysis (PD) patients. Here we evaluated the association of BP levels with the decline of residual kidney function (RKF) in a retrospective cohort study.

Methods

We enrolled 228 patients whose PD was initiated between 1998 and 2014. RKF was measured as the average of creatinine and urea clearance in 24-hr urine collections. We calculated the annual decline rate of RKF by determining the regression line for individual patients. RKF is thought to decline exponentially, and thus we also calculated the annual decline rate of logarithmic scale of RKF (log RKF). We categorized the patients’ BP levels at 3 months after PD initiation (BP_3M) into four groups (Optimal, Normal & High normal, Grade 1 hypertension, Grade 2 & 3 hypertension) according to the 2018 European Society of Cardiology and European Society of Hypertension Guidelines for the management of arterial hypertension.

Results

The unadjusted, age- and sex-adjusted, and multivariable-adjusted decline rate of RKF and log RKF decreased significantly with higher BP_3M levels (P for trend <0.01). Compared to those of the Optimal group, the multivariable-adjusted odds ratios (95% confidence interval) for the faster side of the median decline rate of RKF and log RKF were 4.04 (1.24–13.2) and 5.50 (1.58–19.2) in the Grade 2 and 3 hypertension group, respectively (p<0.05).

Conclusions

Higher BP levels after PD initiation are associated with a faster decline in RKF among PD patients.

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.

KDOQI US Commentary on the 2020 ISPD Practice Recommendations for Prescribing High-Quality Goal-Directed Peritoneal Dialysis

The recently published 2020 International Society for Peritoneal Dialysis (ISPD) practice recommendations regarding prescription of high-quality goal-directed peritoneal dialysis differ fundamentally from previous guidelines that focused on "adequacy" of dialysis. The new ISPD publication emphasizes the need for a person-centered approach with shared decision making between the individual performing peritoneal dialysis and the clinical care team while taking a broader view of the various issues faced by that individual. Cognizant of the lack of strong evidence for the recommendations made, they are labeled as "practice points" rather than being graded numerically. This commentary presents the views of a work group convened by the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) to assess these recommendations and assist clinical providers in the United States in interpreting and implementing them. This will require changes to the current clinical paradigm, including greater resource allocation to allow for enhanced services that provide a more holistic and person-centered assessment of the quality of dialysis delivered.

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.

Single-dwell treatment with a low-sodium solution in hypertensive peritoneal dialysis patients

BACKGROUND

Patients on peritoneal dialysis (PD) may suffer from sodium (Na) and fluid overload, hypertension and increased cardiovascular risk. Low-Na dialysis solution, by increasing the diffusive removal of Na, might improve blood pressure (BP) management.

METHODS

A glucose-compensated, low-Na PD solution (112 mmol/L Na and 2% glucose) was compared to a standard-Na solution (133 mmol/L Na and 1.5% glucose) in a prospective, randomised, single-blind study in hypertensive patients on PD. One daily exchange of the standard dialysis regimen was substituted by either of the study solutions for 6 months. The primary outcome (response) was defined as either a decrease of 24-h systolic BP (SBP) by ≥6 mmHg or a fall in BP requiring a medical intervention (e.g. a reduction of antihypertensive medication) at 8 weeks.

RESULTS

One hundred twenty-three patients were assessed for efficacy. Response criteria were achieved in 34.5% and 29.1% of patients using low- and standard-Na solutions, respectively (p = 0.51). Small reductions in 24 h, office, and self-measured BP were observed, more marked with low-Na than with standard-Na solution, but only the between-group difference for self-measured SBP and diastolic BP was significant (p = 0.002 and p = 0.003). Total body water decreased in the low-Na group and increased in the control group, but between-group differences were not significant. Hypotension and dizziness occurred in 27.0% and in 11.1% of patients in the low-Na group and in 16.9% and 4.6% in the control group, respectively.

CONCLUSIONS

Superiority of low-Na PD solution over standard-Na solution for control of BP could not be shown. The once daily use of a low-Na PD solution was associated with more hypotensive episodes, suggesting the need to reassess the overall concept of how Na-reduced solutions might be incorporated within the treatment schedule.

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.

Automated Remote Monitoring for Peritoneal Dialysis and Its Impact on Blood Pressure

Introduction: Peritoneal dialysis (PD) provides a safe, home-based continuous renal replacement therapy for patients. The adherence of the patients to the prescribed dialysis fluids cannot always be monitored by physicians. Remote monitoring automated peritoneal dialysis (RM-APD) can affect patients’ compliance with treatment and, thus, clinical outcomes. Objective: We aimed to evaluate the clinical outcomes of patients with a remote access program. Methods: This was an observational study. We analyzed the effect of RM-APD on treatment adherence, dialysis adequacy, and change in blood pressure control, sleep quality, and health-related quality of life during the 6 months of follow-up. Results: A total of 15 patients were enrolled in this study. It was found that there was a significant decrease (99 ± 19 vs. 89 ± 11 mm Hg) in mean arterial blood pressure of patients, and a considerable increase in Kt/V was observed in the sixth month after the RM-APD switch (2.11 ± 0.4 vs. 2.25 ± 0.5). A significant increase was found when comparing the 3-month and 6-month ultrafiltration amounts before RM-APD and the ultrafiltration amount within 6 months after RM-APD (800 mL [500–1,000] and 752 mL [490–986] vs. 824 mL [537–1,183]). The daily antihypertensive pill need (4 [0–7] vs. 2 [0–6]) and alarms received from the device decreased (from 4 [3–8] to 2 [0–3]) at the sixth month of the switch. There was no significant change in sleep quality and health-related quality of life within 6 months. Conclusion: This study showed that treatment adherence and ultrafiltration amounts of patients increased with the use of RM-APD, as well as better blood pressure control with fewer antihypertensive drugs.

What is the Link between Poor Ultrafiltration and Increased Mortality in Anuric Patients on Automated Peritoneal Dialysis? Analysis of Data from Eapos

Background

Primary analysis of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS) found that patients with daily ultrafiltration (UF) below a predefined target of 750 mL at baseline experienced increased mortality and continuing low UF over 2 years.

Setting

Multicenter, prospective observational study of prevalent, functionally anuric patients on automated peritoneal dialysis (APD) treated to predefined standards.

Methods

Secondary data analysis to determine clinical covariates that might support a link between poor UF and outcome, including pattern of comorbidity, prescription, nutrition as determined by Subjective Global Assessment (SGA), membrane function, and blood pressure (BP). Ultrafiltration was treated as a categorical (comparing patients above and below target at baseline) and continuous dependent variable in univariate and multivariate regression. The relationship between BP and survival was also explored.

Results

Of 177 patients recruited from 28 centers across Europe, 43 were below the UF target at baseline. Compared to those above target, there were no differences in the spread of comorbidity, type of APD prescription, SGA, BP, hemoglobin, HCO3, or parathyroid hormone, at baseline or at any later time. At baseline, plasma calcium and, at 12 months, plasma phosphate were lower in the low UF group. There was a weak positive correlation between baseline systolic or diastolic BP and UF, which remained on multivariate analysis but accounted for just 9% of the variability in BP. There was no clear relationship between baseline BP and survival, although, if anything, low BP was associated with earlier death. Poor UF was associated with lower mean dialysate glucose concentration during the first 4 months and with consistently worse membrane function.

Conclusions

The increased mortality associated with poor UF is likely multifactorial and not easily explained by clear differences in comorbidity, nutritional state, or other indices of treatment at baseline. The lower plasma phosphate suggests a subsequent fall in appetite. Poor BP control is unlikely to be the explanation, and a link between lower BP, reduced UF, and earlier death is suggested. Failure to achieve adequate UF due to worse membrane function remains an important and potentially reversible or preventable cause.

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.

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.

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.

Very early withdrawal from treatment in patients starting peritoneal dialysis

Introduction: Very early withdrawal from treatment in patients undergoing peritoneal dialysis (PD) is an increasingly important, but poorly understood, issue. Here, we identified the reasons and risk factors for very early withdrawal from PD.

Methods: Incident PD patients from The First Affiliated Hospital of Sun Yat-sen University above 18 years who started treatment between January 1 2006 and December 31 2011 were included. Cessation of PD therapy within the first 90 days after beginning dialysis was classified as very early withdrawal.

Results: Totally 1444 patients were enrolled. Of these, 71 (4.9%) withdrew from PD therapy during the first 90 days. Primary reasons for very early withdrawal included death (34 patients, 47.9%), transplantation (21 patients, 29.6%) and transfer to hemodialysis (14 patients, 19.7%). The leading reasons for death were cardiovascular and infectious disease, accounting for 41.2% (14 patients) and 23.5% (8 patients) of total deaths, respectively. Dialysate leakage (six patients, 42.9%) and catheter dysfunction (five patients, 35.7%) were the main reasons for transfer to hemodialysis. In multivariate analysis, predictors for very early PD withdrawal were older age (per decade increasing; hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.03–1.45; p = .019), higher systolic blood pressure (per 10 mmHg increasing; HR, 1.35; 95% CI, 1.20–1.50; p < .001), lower hemoglobin (per 10 g/l increasing; HR, 0.67; 95% CI, 0.57–0.78; p < .001), lower high-density lipoprotein cholesterol (HR, 0.24; 95% CI, 0.10–0.54; p = .001) and lower residual urine volume (per 100 ml/d increasing; HR, 0.90; 95% CI, 0.84–0.95; p = .001).

Conclusions: Death was the primary reason for very early withdrawal from PD. Risk factors for very early withdrawal from PD were older in age, had higher systolic blood pressure, lower hemoglobin, lower high-density lipoprotein cholesterol and lower residual urine volume.

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.

Six-minute walk test predicts all-cause mortality and technique failure in ambulatory peritoneal dialysis patients

AIM

This study investigated the associated factors of 6-min walk test (6MWT) and its predictive value of outcome in patients undergoing peritoneal dialysis (PD).

METHODS

This is a single centre prospective observational cohort study. Stable ambulatory PD patients in our centre between 1 May 2010 and 30 April 2011 were enrolled in this study. All included subjects performed 6MWT, and 6-min walk distances (6MWDs) were recorded. Patients were divided into two groups according to 6MWD and prospectively followed up until death, cessation of PD or to the end of the study (30 September 2012).

RESULTS

A total of 145 patients were enrolled, including 63 (43%) males. Multiple stepwise regression showed that age (β = -0.295, P = 0.001), diastolic blood pressure (DBP) (β = 0.292, P = 0.001), left ventricular ejection fraction (LVEF) (β = 0.198, P = 0.019) were independently associated with lower 6MWD. By the end of the study, six (8%) patients died in long 6MWD group while 15 (20%) died in the short 6MWD group, a significantly lower patient survival was observed in short 6MWD group (Log-rank = 4.983, P = 0.026). Patients with short 6MWD also showed inferior technique survival (Log-rank = 4.838, P = 0.028). There was no significant difference in peritonitis-free survival between the two groups (Log-rank = 0.801, P = 0.371). However, more patients in short 6MWD group had been transferred to hemodialysis due to peritonitis (25% vs 4.2%, P = 0.013).

CONCLUSION

Age, diastolic blood pressure, LVEF are independent associated factors of 6MWD in patients undergoing PD. Having the advantages of easy applicability and safety, 6MWT may be proposed as an important predictor of outcome in ambulatory PD patients.

Peritoneal dialysis impairs nitric oxide homeostasis and may predispose infants with low systolic blood pressure to cerebral ischemia

BACKGROUND & PURPOSE

Infants on chronic peritoneal dialysis (PD) have an increased risk of developing neurological morbidities; however, the underlying biological mechanisms are poorly understood. In this clinical study, we investigated whether PD-mediated impairment of nitric oxide (NO) bioavailability and signaling, in patients with persistently low systolic blood pressure (SBP), can explain the occurrence of cerebral ischemia.

METHODS & RESULTS

Repeated blood pressure measurements, serial neuroimaging studies, and investigations of systemic nitrate and nitrite levels, as well as NO signaling, were performed in ten pediatric patients on PD. We consistently observed the loss of both inorganic nitrate (-17 ± 3%, P < 0.05) and nitrite (-34 ± 4%, P < 0.05) during PD, which may result in impairment of the nitrate-nitrite-NO pathway. Indeed, PD was associated with significant reduction of cyclic guanosine monophosphate levels (-59.4 ± 15%, P < 0.05). This reduction in NO signaling was partly prevented by using a commercially available PD solution supplemented with l-arginine. Although PD compromised nitrate-nitrite-NO signaling in all cases, only infants with persistently low SBP developed ischemic cerebral complications.

CONCLUSIONS

Our data suggests that PD impairs NO homeostasis and predisposes infants with persistently low SBP to cerebral ischemia. These findings improve current understanding of the pathogenesis of infantile cerebral ischemia induced by PD and may lead to the new treatment strategies to reduce neurological morbidities.

Reverse Epidemiology of Blood Pressure in Peritoneal Dialysis Associated with Dynamic Deterioration of Left Ventricular Function

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BACKGROUND

Reverse epidemiology of blood pressure (BP) in end-stage kidney disease (ESKD) is manifested as higher mortality at lower blood pressure. We hypothesize that this phenomenon is partially mediated by deterioration of cardiac structure and function. ♦

METHODS

Seventy-seven prevalent ESKD patients starting renal replacement therapy on peritoneal dialysis (PD) from 2007 to 2012 were evaluated for the primary outcome of all-cause mortality. Longitudinal data were obtained from 1,930 patient-encounters including monthly clinic BP and serial echocardiograms. Generalized linear mixed models using data from the last observation moving backward, and time-to-event analysis using time-varying Cox-survival models to estimate mortality risk at different blood pressure categories were applied. ♦

RESULTS

There were 39 males (50.6%). Mean age was 51 years (standard deviation [SD] = 15). During follow-up, 20 patients (25%) died. As compared to systolic blood pressure (SBP) of 140-159 mmHg, unadjusted risk of mortality was 7.3 (95% confidence interval [CI]: 1.5-35.7, p = 0.008) at level < 120 mmHg. Systolic BP trended down to an average of 117 mmHg prior to death in non-survivors as compared to 141 mmHg in survivors (p < 0.05). In non-survivors, percentage with concentric left ventricular hypertrophy (LVH) decreased by 20% at the expense of a 20% reciprocal increase in eccentric hypertrophy associated with a 30% increase in percentage with low ejection fraction (EF) (< 50%). After adjusting for EF, risk of mortality at SBP < 120 mmHg attenuated to 3.4 (95% CI: 0.7-17.7, p = 0.14). ♦

CONCLUSION

We conclude that higher mortality associated with lower BP may be mediated in part by worsening heart function in ESKD patients receiving PD.

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.

Association of pre-transplant blood pressure with post-transplant outcomes

BACKGROUND

Previous studies have indicated U-shaped associations between blood pressure (BP) and mortality in dialysis patients. We hypothesized that a similar association exists between pre-transplant BP and post-transplant outcomes in dialysis patients who undergo successful kidney transplantation.

METHODS

Data from the Scientific Registry of Transplant Recipients were linked to the five-yr cohort of a large dialysis organization in the United States. We identified all dialysis patients who received a kidney transplant during this period. Unadjusted and multivariate adjusted predictors of transplant outcomes were examined.

RESULTS

A total of 13 881 patients included in our study were 47 ± 14 yr old and included 42% women. There was no association between pre-transplant systolic BP and post-transplant mortality, although a decreased risk trend was observed in those with low post-dialysis systolic BP. Compared to patients with pre-dialysis diastolic BP 70 to <80 mmHg, patients with pre-dialysis diastolic BP <50 mmHg experienced lower risk of post-transplant death (hazard ratios [HR]: 0.74, 95% CI: 0.55-0.99). However, compared to patients with post-dialysis diastolic BP 70 to <80 mmHg, patients with post-dialysis diastolic BP ≥100 mmHg experienced higher risk of death (HR: 3.50, 95% CI: 1.57-7.84). In addition, very low (<50 mmHg for diastolic BP and <110 mmHg for systolic BP) pre-transplant BP was associated with lower risk of graft loss.

CONCLUSIONS

Low post-dialysis systolic BP and low pre-dialysis diastolic BP are associated with lower post-transplant risk of death, whereas very high post-dialysis diastolic BP is associated with higher mortality in kidney transplant recipients. BP variations in dialysis patients prior to kidney transplantation may have a bearing on post-transplant outcome, which warrants additional studies.

Blood pressure measurement in peritoneal dialysis: which method is best?

BACKGROUND

The optimal approach to monitoring blood pressure (BP) in the peritoneal dialysis (PD) population is unclear. Ambulatory BP monitoring reliably predicts prognosis, but can be inconvenient. The accuracy of home BP monitoring in this population is unproven. The automated BpTRU device (BpTRU Medical Devices, Coquitlam, BC, Canada), which provides an average of up to 6 successive in-office BP measurements, has not been studied in this patient group.

METHODS

We studied 17 patients (average age: 54 ± 12 years; 12 men, 5 women; 94% on automated PD) attending a single center. All patients underwent office, home, BpTRU, and ambulatory BP measurement. The reference standard for analysis was daytime ambulatory BP. Correlation between the referent method and each comparator method was determined (Pearson correlation coefficient), and Bland-Altman scatter plots depicting the differences in the BP measurements were constructed.

RESULTS

Mean office BP (126.4 ± 16.9/78.8 ± 11.6 mmHg) and BpTRU BP (123.8 ± 13.7/80.7 ± 11.1 mmHg) closely approximated mean daytime ambulatory BP (129.3 ± 14.8/78.2 ± 7.9 mmHg). Mean home BP (143.8 ± 15.0/89.9 ± 28.1 mmHg) significantly overestimated mean daytime systolic BP by 14.2 mmHg (95% confidence interval: 4.3 mmHg to 24.1 mmHg; p = 0.008). Bland-Altman plots demonstrated poorest agreement between home BP and daytime ambulatory BP. No patient had "white-coat hypertension," and only 1 patient had false-resistant hypertension. Most patients showed abnormal nocturnal dipping patterns (non-dipping: n = 11; reverse-dipping: n = 5; normal dipping: n = 1).

CONCLUSIONS

We report a novel finding that BP measurement using the BpTRU device is more accurate than home BP measurement in a PD population. Potential explanations for this observation include poor home BP measurement technique, use of poorly validated home BP measurement devices, or a reduced prevalence of white-coat effect among PD patients. Our study also confirms that, in the PD population, BP measurements vary considerably with patient location, time of day, and measurement technique.

Association of blood pressure with the start of renal replacement therapy in elderly compared with young patients receiving predialysis care

BACKGROUND

In the growing elderly predialysis population, little is known about the effect of identified risk factors on the progression to end-stage renal disease. Therefore, we investigated the association of systolic (SBP) and diastolic blood pressure (DBP) with the start of renal replacement therapy (RRT), in elderly (≥65 years) compared with young (<65 years) predialysis patients.

METHODS

In the PREPARE-1 cohort, 547 incident predialysis patients, referred as part of the usual care to eight Dutch predialysis care outpatient clinics, were included (1999-2001) and followed until the start of dialysis, transplantation, death, or until 1 January 2008. The outcome was the start of RRT. All analyses were stratified for age; <65 years (young) and ≥65 years (elderly).

RESULTS

In young predialysis patients (n = 268) higher SBP (every 20 mm Hg increase) and high DBP (DBP ≥100 mm Hg compared with 80-89 mm Hg) were associated with a higher rate of starting RRT (adjusted hazard ratio (HR) (95% confidence interval) 1.21 (1.09;1.34) and 1.74 (1.16;2.62), respectively). However, in elderly predialysis patients (n = 240) only patients with SBP ≥180 mm Hg had an increased rate compared with patients with 140-159 mm Hg (adjusted HR 2.33 (1.41;3.87)). Furthermore, patients with DBP <70 or ≥100 mm Hg had an increased rate of starting RRT, independent of SBP, compared with patients with 80-89 mm Hg (fully adjusted HR 1.72 (1.01;2.94) and 2.05 (1.13;3.73), respectively).

CONCLUSIONS

The association of SBP and DBP with the start of RRT is different between elderly and young predialysis patients.

Chronic Inflammation and Coronary Atherosclerosis in Patients with End-Stage Renal Disease

The key role of chronic inflammation in the pathogenesis of atherosclerosis has become increasingly apparent in recent years based on the results of experimental, epidemiologic and clinical studies. Coronary artery disease and its complications occur with disproportionately high frequency in patients with end-stage renal disease (ESRD) and contribute substantially to cardiovascular morbidity and mortality in this population. Traditional cardiovascular risk factors occur commonly in patients with ESRD. In addition, a variety of patient-related and dialysis-related factors unique to ESRD predispose to chronic inflammation and by doing so are thought to contribute to coronary atherosclerosis and its complications. These risk factors may serve as therapeutic targets and as such may offer the potential for altering the natural history of coronary atherosclerosis in ESRD.

UK Renal Registry 13th Annual Report (December 2010): Chapter 11: blood pressure profile of prevalent patients receiving renal replacement therapy in England, Wales and Northern Ireland in 2009: national and centre-specific analyses

BACKGROUND

The UK Renal Registry (UKRR) assesses blood pressure (BP) control annually for patients receiving Renal Replacement Therapy (RRT) at renal centres in England, Wales and Northern Ireland.

METHODS

Patients alive and receiving RRT on 31st December 2009 with a BP reading in either the fourth or third quarter of 2009 were included. Summary statistics were calculated for each renal centre and country.

RESULTS

Data completeness for BP measurements submitted to the UKRR for all modalities improved from the previous year and was better for HD patients (67% for pre-HD measurements) than for PD patients (44%) or transplant recipients (37%). In 2009, the median pre-and post-HD SBP were 142 mmHg and 129 mmHg respectively. The median SBP of patients on PD was 137 mmHg. Transplant recipients had a median SBP of 134 mmHg. Median DBP were 74 mmHg (pre-HD), 68 mmHg (post-HD), 79 mmHg (PD) and 79 mmHg (transplant). Only 26.7% of PD patients achieved the Renal Association guideline of SBP <130 mmHg and DBP <80 mmHg. Amongst transplant patients, 27.2% achieved the Renal Association guideline of SBP <130 mmHg and DBP <80 mmHg.

CONCLUSION

In 2009 there continued to be significant variation in the achievement of BP standards between UK renal centres.

Can we reduce the cardiovascular risk in peritoneal dialysis patients?

Patients with end-stage renal disease (ESRD), including those treated with peritoneal dialysis (PD), have a high risk for death, particularly from cardiovascular (CV) causes. Traditional risk factors for CV disease – like hypertension, diabetes, and dyslipidemia - are highly prevalent, often severe, and more difficult to treat in dialysis patients. Development of strategies for CV risk reduction in dialysis patients is complicated by epidemiologic studies that demonstrate paradoxical associations of some of the traditional risk factors with mortality. The difficulty is enhanced by either a paucity or negative findings of studies that have tested risk modification by targeting traditional CV risk factors. It is also clear that neither the prevalence nor the severity of traditional risk factors explains the substantial increase in risk for death associated with ESRD; this has led to identification of several nontraditional risk factors. Among these, systemic inflammation, disordered mineral metabolism, and long-term CV risk from infectious complications appear the most promising. However, the evidence in favor of the importance of these risk factors is largely limited to observational studies. In this review, we present a critical analysis of the literature to assist the clinician to reduce the CV risk of ESRD patients treated with PD.

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.

Management of hypertension in hemodialysis patients

Hypertension is very common in patients with chronic kidney disease and is present in most patients with end-stage renal disease (ESRD). Hypertension is largely responsible for premature cardiovascular disease in dialysis patients. The pathophysiology of hypertension in ESRD is complex, and multiple mechanisms are likely involved in blood pressure dysregulation in patients on hemodialysis. Some of these patients demonstrate resistant hypertension. Aggressive control of hypertension in ESRD/dialysis is mandatory. Generally, nonpharmacologic treatments are not enough to achieve the goal blood pressure levels in dialysis patients. Multiple antihypertensive drugs are often necessary. Drugs that block the renin-angiotensin system offer a number of advantages for patients with chronic kidney disease or ESRD, but additional drug classes are often needed to achieve effective blood pressure control in dialysis patients. Physicians treating hypertension in dialysis patients should be familiar with the pharmacokinetic properties of antihypertensive drugs in renal failure and choose the dosages accordingly. Vigorous control of hypertension is recommended to reduce the disease burden in patients with ESRD.

The scope of coronary heart disease in patients with chronic kidney disease

Chronic kidney disease (CKD) affects approximately 13% of the U.S. population and is associated with increased risk of cardiovascular complications. Once renal replacement therapy became available, it became apparent that the mode of death of patients with advanced CKD was more likely than not related to cardiovascular compromise. Further observation revealed that such compromise was related to myocardial disease (related to hypertension, stiff vessels, coronary heart disease, or uremic toxins). Early on, the excess of cardiovascular events was attributed to accelerated atherosclerosis, inadequate control of blood pressure, lipids, or inflammatory cytokines, or perhaps poor glycemia control. In more recent times, outcome research has given us further information that relates even lesser degrees of renal compromise to an excess of cardiovascular events in the general population and in those with already present atherosclerotic disease. As renal function deteriorates, certain physiologic changes occur (perhaps due to hemodynamic, inflammatory, or metabolic changes) that decrease oxygen-carrying capacity of the blood by virtue of anemia, make blood vessels stiffer by altering collagen or through medial calcinosis, raise the blood pressure, increase shearing stresses, or alter the constituents of atherosclerotic plaque or the balance of thrombogenesis and thrombolysis. At further levels of renal dysfunction, tangible metabolic perturbations are recognized as requiring specific therapy to reduce complications (such as for anemia and hyperparathyroidism), although outcome research to support some of our current guidelines is sorely lacking. Understanding the process by which renal dysfunction alters the prognosis of cardiac disease might lead to further methods of treatment. This review will outline the relationship of CKD to coronary heart disease with respect to the current understanding of the traditional and nontraditional risk factors, the role of various imaging modalities, and the impact of coronary revascularization on outcome.

Hypertension in dialysis and kidney transplant patients

For the first time, the Canadian Hypertension Education Program has studied the evidence supporting blood pressure control in people requiring renal replacement therapy for end-stage kidney disease, including those on dialysis and with renal transplants. According to the Canadian Organ Replacement Registry's 2008 annual report, there were an estimated 33,832 people with end-stage renal disease in Canada at the end of 2006, an increase of 69.7% since 1997. Of these, 20,465 were on dialysis and 13,367 were living with a functioning kidney transplant. Thus, it is becoming more likely that primary care practitioners will be helping to care for these complex patients. With the lack of large controlled clinical trials, the consensus recommendation based on interpretation of the existing literature is that blood pressure should be lowered to below 140/90 mmHg in hypertensive patients on renal replacement therapy and to below 130/80 mmHg for renal transplant patients with diabetes or chronic kidney disease.

Blood pressure and mortality risk on peritoneal dialysis

BACKGROUND

The association of baseline blood pressure (BP) and mortality in incident peritoneal dialysis patients has not been adequately studied.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

2,770 patients on PD therapy at 180 days from start of renal replacement therapy in England and Wales between 1997 and 2004.

PREDICTORS

Systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) measured in the first 6 months of renal replacement therapy and other baseline demographic and laboratory variables.

OUTCOMES

All-cause mortality was studied using time-stratified Cox regression models (to account for nonproportionality) dividing follow-up time into 4 intervals: year 1 (days 180 to 365), years 2 to 3, years 4 to 5, and years 6+. Interactions between BP components and transplant waitlist and diabetes status were explored.

RESULTS

Median follow-up was 3.7 years (range, 0.1 to 9.9 years), and 1,104 deaths were observed. In fully adjusted analyses, greater SBP, DBP, MAP, and PP were associated with decreased mortality in the first year, but greater SBP and PP were associated with increased late mortality (in years 6+). However, in the subgroup of patients placed on the transplant waitlist within 6 months of starting renal replacement therapy, greater SBP, DBP, MAP, and PP were not associated with decreased mortality in the first year.

LIMITATIONS

Exclusion of 3,086 patients because of missing BP data. No data were available for cardiac function or antihypertensive medication.

CONCLUSIONS

Although greater SBP, DBP, MAP, and PP appear protective against early mortality in the overall cohort, this effect is not seen in patients registered on the national transplant waiting list within 6 months of starting renal replacement therapy.

[Fluid and sodium balance and blood pressure control in APD/CAPD]

Cardiovascular disease remains the leading cause of death in ESRD patients related to long-standing hypertension. Early studies had recognized the favourable effect of PD in controlling hypertension but it was soon realized that such benefit was not sustained. A U shaped trend of hypertension in patients on PD has been recently demonstrated as a result of a steadily increased blood pressure partly attributed to fluid retention resulting from lower sodium removal with time. Effort in selecting the best strategy of ultrafiltration for a single patient along with a careful and frequent monitoring of combined 24 hours sodium elimination coupled with dietician counseling can improve significantly fluid an sodium balance which in turn will result in much better blood pressure control. The contribution of progress in biocompatibility of PD fluid that better preserve renal function and the implementation of the first glucose polymer Icodextrin were key interventions in that aim. Further studies should be conducted to assess the power of innovative PD solutions--Low Sodium PDF and/or Bimodal Ultrafiltration--in enhancing fluid and sodium removal during CAPD/APD programmes.

The association between blood pressure and mortality in ESRD-not different from the general population?

Hypertension (HTN) is a traditional cardiovascular risk factor and is prevalent in end-stage renal disease (ESRD). There are no adequately powered prospective studies that explore the natural history and outcomes of HTN and blood pressure management in ESRD. Observational studies have not uniformly showed a relationship between HTN and mortality risk in this population. Furthermore, many studies paradoxically show an increased risk of death associated with low and "normal" blood pressure (BP), sometimes referred to as "reverse epidemiology." We review findings from observational studies specifically performed in ESRD and provide an alternative interpretation-that patients with kidney disease on dialysis therapy are indeed different from the general population. At minimum, these differences may be based on the prevalence of cardiovascular morbidity, specifically the excessive prevalence of congestive heart failure. However, there are other reasons for ESRD patients, especially those on hemodialysis, to exhibit differential effects with regard to blood pressure and outcomes. We explore the implications of available observational evidence and recommend studies that elucidate the differences between ESRD and the general population. Because of the higher mortality risk associated with low or "normal" BP, diagnostic and therapeutic options and strategies for ESRD patients whose BP falls within "goal" should be addressed in future iterations of clinical practice guidelines. These strategies may include assessment of cardiac function and careful attention to achieving optimal fluid balance.

[Does hypertension impact on the mortality of hemodialysis patients?]

Hypertension is very common in standard haemodialysis patients in spite of a wide use of antihypertensive medications. Up to the last decade it was reported in dialysis nts, as in the general population, as a powerful mortality risk factor. More recently several reports have challenged this view, and hypotension rather than hypertension has been claimed as the real culprit. That a risk factor has an opposite effect on mortality in conditions such as dialysis than in the general population has been termed - reverse epidemiology ,,, and suggests that our therapeutic approach toward blood pressure control in dialysis should be reconsidered. In fact, this counter intuitive concept is explained by the effect of time. Hypertension is a long-term mortality risk factor, that in a population crippled by short-acting risk factors (e.g. diabetes, congestive heart failure, malnutrition...) has not the opportunity to express itself. The clear cut noxious effect of hypertension on mortality in the years when dialysis patients were young and fit has disappeared in the present aged and highly co-morbid population. This does not mean that hypertension becomes beneficial once dialysis has been started. Hypotension is a marker of a high risk of early mortality, hypertension is a cause of late mortality. There is no evidence that hypertension might be protective in dialysis patients. Avoiding hypertension remains a capital goal of maintenance dialysis.

Racial and survival paradoxes in chronic kidney disease

Most of the 20 million people in the US with chronic kidney disease (CKD) die before commencing dialysis. One of every five dialysis patients dies each year in the US. Although cardiovascular disease is the most common cause of death among patients with CKD, conventional cardiovascular risk factors such as hypercholesterolemia, hypertension and obesity are paradoxically associated with better survival in hemodialysis populations. Emerging data indicate the existence of this 'reverse epidemiology' in earlier stages of CKD. There are also paradoxical relationships between outcomes and race and ethnicity. For example, the survival rate of African American dialysis patients seems to be superior to that of whites on dialysis. Paradoxes-within-paradoxes have been detected among Hispanic and Asian American CKD patients. These survival paradoxes might evolve and change over the natural course of CKD progression as a result of the time differentials of competing risk factors and the overwhelming impact of malnutrition, inflammation and wasting. Reversal of the reverse epidemiology as a result of successful kidney transplantation underscores the role of nutritional status and kidney function in engendering these paradoxes. The observation of paradoxes and their reversal might lead to the formulation of new paradigms and management strategies to improve the survival of patients with CKD. Such movement away from the use of targets set on the basis of data gathered in general populations (e.g. the Framingham cohort) would be a major paradigm shift in clinical medicine and public health.