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

Cardiovascular and All-Cause Mortality Is Affected by Serum Magnesium and Diet Pattern in a Cohort of Dialysis Patients

Background: Hypomagnesaemia is associated with an increased overall mortality in patients with chronic kidney disease on dialysis (CKD-5D). Mediterranean-style diet (MD), having a high magnesium content, can serve as a form of dietary magnesium supplementation. We examined whether there is a potential link between increased Mediterranean Diet score (MDS) and elevated serum magnesium (sMg) to assess its impact on reducing mortality risk in CKD-5D patients. Methods: In this multi-center prospective observational study, 117 CKD-5D patients (66 on hemodialysis and 51 on peritoneal dialysis) with a mean age of 62 ± 15 years were studied for a median follow-up period of 68 months. After baseline assessment, including measurement of sMg and MDS, all patients were followed up for cardiovascular (CV) and all-cause mortality. Results: Forty deaths occurred, 58% of which were cardiovascular. Patients who were above the median value of sMg (2.2 mg/dL) had a 66% reduction in CV (crude HR, 0.34; 95% CI, 0.11-0.70), and 49% reduction in all-cause (crude HR, 0.51; 95% CI, 0.27-0.96) mortality, even after adjustment for age, malnutrition inflammation score, left ventricular mass index, peripheral vascular disease and diabetes. Similar results were obtained when sMg was analyzed as a continuous variable. sMg was associated directly with MDS (r = 0.230; p = 0.012). Conclusions: Higher sMg levels are strongly and independently associated with reduced CV and all-cause mortality in CKD-5D patients. A strong correlation exists between MDS and sMg. Elevated sMg levels, achieved through MD adherence, can significantly reduce CV mortality, implicating MD as a mediator of the association between sMg and CV mortality.

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

Which blood pressure metrics should be used in patients on dialysis?

Remarkable progress has recently been achieved in blood pressure (BP) control based on key research findings in the general population. It has been observed that maintaining BP slightly lower than previously recommended goals leads to better clinical outcomes, provided that patients can tolerate it. Previously, BP control targets for dialysis patients were extrapolated from studies conducted on the general population. However, dialysis patients are considered a distinct group with unique characteristics, which makes defining appropriate BP targets a matter of debate. Several observational studies measuring BP in hemodialysis (HD) patients within dialysis units have shown that lower peridialysis BP (pre-, post-, and interdialytic BP) is associated with worse clinical outcomes. However, this association is likely confounded by factors specific to dialysis patients. The relationship between BP and mortality appears to be more linear in patients with fewer underlying cardiovascular diseases and longer survival. Recent studies have indicated that BP measurements taken outside of dialysis sessions, such as standardized BP on nondialysis days, home BP, and ambulatory BP monitoring between HD sessions, are more predictive of clinical outcomes. Due to the varied effects of dialysis-related treatment practices on BP, there is a lack of data from large-scale clinical trials. As a result, it is challenging to provide strong recommendations for BP targets directly applicable to dialysis patients. This review addresses various factors influencing BP in dialysis patients, including the establishment of individualized target BP levels and discussions on maintenance strategies, while incorporating a recent literature review.

Construction of an Early Alert System for Intradialytic Hypotension before Initiating Hemodialysis Based on Machine Learning

Introduction

Intradialytic hypotension (IDH) is prevalent and associated with high hospitalization and mortality rates. The purpose of this study was to explore the risk factors for IDH and use artificial intelligence to establish an early alert system before hemodialysis sessions to identify patients at high risk of IDH.

Materials and Methods

We obtained data on 314,534 hemodialysis sessions conducted at Sichuan Provincial People's Hospital from the renal disease treatment information system. IDH was defined as a systolic blood pressure drop ≥20 mm Hg, a mean arterial pressure drop ≥10 mm Hg during dialysis, or the occurrence of clinical hypotensive events requiring nursing intervention. After pre-processing, the data were randomly divided into training (80%) and testing (20%) sets. Four interpolation methods, three feature selection methods, and 18 machine learning algorithms were used to construct predictive models. The area under the receiver operating characteristic curve (AUC) was the main indicator for evaluating the performance of the models, while Shapley Additive ExPlanation was used to explain the contribution of each variable to the best predictive model.

Results

A total of 3,906 patients and 314,534 dialysis sessions were included, of which 142,237 cases showed IDH (incidence rate, 45.2%). Nineteen parameters were identified through artificial intelligence feature screening. They included age, pre-dialysis weight, dry weight, pre-dialysis blood pressure, heart rate, prescribed ultrafiltration, blood cell counts (neutrophil, lymphocyte, monocyte, eosinophil, lymphocyte, and platelet counts), hematocrit, serum calcium, creatinine, urea, glucose, and uric acid. Random forest, gradient boosting, and logistic regression were the three best models, and the AUCs were 0.812 (95% confidence interval [CI], 0.811-0.813), 0.748 (95% CI, 0.747-0.749), and 0.743 (95% CI, 0.742-0.744), respectively.

Conclusion

Our dialysis software-based artificial intelligence alert system can be used to predict IDH occurrence, enabling the initiation of relevant interventions.

Vitamin D Metabolites and Risk of Cardiovascular Disease in Chronic Kidney Disease: The CRIC Study

Background The ratio of 24,25-dihydroxyvitamin D3/25-hydroxyvitamin D3 (vitamin D metabolite ratio [VDMR]) may reflect functional vitamin D activity. We examined associations of the VDMR, 25-hydroxyvitamin D (25[OH]D), and 1,25-dihydroxyvitamin D (1,25[OH]2D) with cardiovascular disease (CVD) in patients with chronic kidney disease. Methods and Results This study included longitudinal and cross-sectional analyses of 1786 participants from the CRIC (Chronic Renal Insufficiency Cohort) Study. Serum 24,25-dihydroxyvitamin D3, 25(OH)D, and 1,25(OH)2D were measured by liquid chromatography-tandem mass spectrometry 1 year after enrollment. The primary outcome was composite CVD (heart failure, myocardial infarction, stroke, and peripheral arterial disease). We used Cox regression with regression-calibrated weights to test associations of the VDMR, 25(OH)D, and 1,25(OH)2D with incident CVD. We examined cross-sectional associations of these metabolites with left ventricular mass index using linear regression. Analytic models adjusted for demographics, comorbidity, medications, estimated glomerular filtration rate, and proteinuria. The cohort was 42% non-Hispanic White race and ethnicity, 42% non-Hispanic Black race and ethnicity, and 12% Hispanic ethnicity. Mean age was 59 years, and 43% were women. Among 1066 participants without prevalent CVD, there were 298 composite first CVD events over a mean follow-up of 8.6 years. Lower VDMR and 1,25(OH)2D were associated with incident CVD before, but not after, adjustment for estimated glomerular filtration rate and proteinuria (hazard ratio, 1.11 per 1 SD lower VDMR [95% CI, 0.95-1.31]). Only 25(OH)D was associated with left ventricular mass index after full covariate adjustment (0.6 g/m2.7 per 10 ng/mL lower [95% CI, 0.0-1.3]). Conclusions Despite modest associations of 25(OH)D with left ventricular mass index, 25(OH)D, the VDMR, and 1,25(OH)2D were not associated with incident CVD in chronic kidney disease.

Home Pulse Pressure Predicts Death and Cardiovascular Events in Peritoneal Dialysis Patients

Increased arterial hypertension represents a prevalent condition in peritoneal dialysis patients that is often related to volume expansion. Pulse pressure is a robust predictor of mortality in dialysis patients, but its association with mortality is unknown in peritoneal patients. We investigated the relationship between home pulse pressure and survival in 140 PD patients. During a mean follow-up of 35 months, 62 patients died, and 66 experienced the combined event death/CV events. In a crude COX regression analysis, a five-unit increase in HPP was associated with a 17% increase in the hazard ratio of mortality (HR: 1.17, 95% CI 1.08-1.26 p < 0.001). This result was confirmed in a multiple Cox model adjusted for age, gender, diabetes, systolic arterial pressure, and dialysis adequacy (HR: 1.31, 95% CI 1.12-1.52, p = 0.001). Similar results were obtained considering the combined event death-CV events as an outcome. Home pulse pressure represents, in part, arterial stiffness, and it is strongly related to all-cause mortality in peritoneal patients. In these high cardiovascular risk populations, it is important to maintain optimal blood pressure control, but it is fundamental to consider all the other cardiovascular risk indicators, such as pulse pressure. Home pulse pressure measurement is easy and feasible and can add important information for the identification and management of high-risk patients.

Blood Pressure Levels, Cardiovascular Events, and Renal Outcomes in Chronic Kidney Disease Without Antihypertensive Therapy: A Nationwide Population-Based Cohort Study

BACKGROUND

High blood pressure (BP) is highly prevalent in patients with chronic kidney disease. However, the thresholds to initiate BP-lowering treatment in this population are unclear. We aimed to examine the associations between BP levels and clinical outcomes and provide evidence on potential thresholds to initiate BP-lowering therapy in people with chronic kidney disease.

METHODS

This nationwide, multicenter, prospective cohort study included 12 523 chronic kidney disease participants without antihypertensive therapy in mainland China. Participants were followed up during 2011 to 2016 for cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, hospitalized or treated heart failure, and cardiovascular death) and renal events (≥20% decline in the estimated glomerular filtration rate, end-stage kidney disease, and renal death).

RESULTS

Overall, 652 cardiovascular events and 1268 renal events occurred during 43 970 person-years of follow-up. We observed a positive and linear relationship between systolic BP and risks of cardiovascular and renal events down to 90 mm Hg, as well as between diastolic BP and risks of renal events down to 50 mm Hg. A J-shaped trend was noted between diastolic BP and risks of cardiovascular events, but a linear relationship was revealed in participants <60 years (P for interaction <0.001). A significant increase in the risk of cardiovascular and renal outcomes was observed at systolic BP ≥130 mm Hg (versus 90-119 mm Hg) and at diastolic BP ≥90 mm Hg (versus 50-69 mm Hg).

CONCLUSIONS

In people with chronic kidney disease, a higher systolic BP/diastolic BP level (≥130/90 mm Hg) is significantly associated with a greater risk of cardiovascular and renal events, indicating potential thresholds to initiate BP-lowering treatment.

Hypertension in Dialysis Patients: Diagnostic Approaches and Evaluation of Epidemiology

Whereas hypertension is an established cardiovascular risk factor in the general population, the contribution of increased blood pressure (BP) to the huge burden of cardiovascular morbidity and mortality in patients receiving dialysis continues to be debated. In a large part, this controversy is attributable to particular difficulties in the accurate diagnosis of hypertension. The reverse epidemiology of hypertension in dialysis patients is based on evidence from large cohort studies showing that routine predialysis or postdialysis BP measurements exhibit a U-shaped or J-shaped association with cardiovascular or all-cause mortality. However, substantial evidence supports the notion that home or ambulatory BP measurements are superior to dialysis-unit BP recordings in diagnosing hypertension, in detecting evidence of target-organ damage and in prognosticating the all-cause death risk. In the first part of this article, we explore the accuracy of different methods of BP measurement in diagnosing hypertension among patients on dialysis. In the second part, we describe how the epidemiology of hypertension is modified when the assessment of BP is based on dialysis-unit versus home or ambulatory recordings.

Hot spring bathing is associated with a lower prevalence of hypertension among Japanese older adults: a cross-sectional study in Beppu

Hot spring bathing is practiced to help manage various diseases, including hypertension. We investigated the preventive effects on hypertension of hot spring bathing among older adults in a data analysis using responses to a previous questionnaire with the aim to identify a novel approach in the prevention and management of hypertension. Among 10,428 adults aged ≥ 65 years, we assessed the hot spring bathing habits of 4001 individuals with a history of hypertension. We calculated odds ratios (OR) with 95% confidence intervals using a multivariable logistic regression model for history of hypertension. In multivariable logistic regression, age (≥ 85 years: OR, 1.410); history of arrythmia (OR, 1.580), stroke (OR, 1.590), gout (OR, 1.880), diabetes mellitus (OR, 1.470), hyperlipidemia (OR, 1.680), renal disease (OR, 1.520), chronic hepatitis (OR, 0.648); and hot spring bathing at 19:00 or later (OR, 0.850) were independently and significantly associated with hypertension during the lifetime. We found an inverse relationship between habitual nighttime hot spring bathing and a history of depression. Prospective randomized controlled trials on nighttime hot spring bathing as a treatment for hypertension are warranted to investigate whether nighttime hot spring bathing can help in preventing hypertension among adults aged ≥ 65 years.

Association of rheumatoid arthritis with mortality in chronic kidney disease: a cohort study

BACKGROUND

Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD) as well as with an increased risk of chronic kidney disease (CKD), also a known cardiovascular risk factor. However, it is not known if RA is a predictor of adverse outcomes in patients with CKD. We hypothesized that among a cohort of patients with CKD, RA would be associated with an increased risk of mortality.

MATERIALS AND METHODS

We conducted a retrospective study of 3939 participants with CKD from the prospective Chronic Renal Insufficiency Cohort (CRIC) study. The primary outcome of interest was all-cause mortality. Secondary outcomes included CKD progression (defined as end-stage kidney disease or 50% decline in estimated glomerular filtration rate), cardiovascular endpoints, and composite of myocardial infarction, cerebrovascular accident, heart failure, or death. Multivariable Cox proportional hazards regression was utilized, adjusting for potential confounders including age, sex, race/ethnicity, body mass index, current smoker, and education.

RESULTS

The study cohort included 83 participants with RA on a disease modifying anti-rheumatic drug (DMARD). In the adjusted analysis, CKD-RA status was significantly associated with an increased risk of death (adjusted HR, aHR, 1.73 (1.27, 2.35)) and composite outcome (aHR 1.65 (1.27-2.15)) even after adjusting for traditional risk factors. Similar statistically significant associations were observed between CKD-RA and other secondary outcomes except for CKD progression.

CONCLUSION

RA was associated with higher mortality among individuals with CKD but not progressive renal decline. Further studies evaluating the mechanisms behind this association are needed. Key Points • Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD) as well as with an increased risk of chronic kidney disease (CKD), also a known cardiovascular risk factor. However, it is not known if RA is an independent predictor of adverse outcomes in patients with CKD • In this study, we observed that CKD patients with RA experience higher mortality as well as an increased risk of CVD compared to patients with CKD without comorbid RA • These data provide rationale for more aggressive monitoring for CVD in patients with CKD and RA. They also underscore the need for determining which interventions can help decrease the burden of mortality in these patients.

The Extracellular Mass to Body Cell Mass Ratio as a Predictor of Mortality Risk in Hemodialysis Patients

The extracellular mass/body cell mass ratio (ECM/BCM ratio) is a novel indicator of nutritional and hydration status in hemodialysis (HD) patients. This study aimed to explore the ECM/BCM ratio as a predictor of mortality risk with nutritional-inflammatory markers in HD patients. A prospective observational study was conducted in 90 HD patients (male: 52.2%; DM: 25.60%). Clinical and biochemical parameters [serum albumin, serum C-reactive protein (s-CRP), interleukine-6 (IL-6)] were analysed and bioelectrical impedance analysis (BIA) was performed. Protein-energy wasting syndrome (PEW) was diagnosed using malnutrition-inflammation score (MIS). Based on BIA-derived measurements, the ECM/BCM ratio with a cut-off point of 1.20 was used as a PEW-fluid overload indicator. Comorbidity by Charlson index and hospital admissions were measured. Out of 90 HD patients followed up for 36 months, 20 patients (22.22%) died. PEW was observed in 24 survivors (34.28%) and all non-survivors. The ECM/BCM ratio was directly correlated with MIS, s-CRP, Charlson index and hospital admissions but was negatively correlated with phase angle and s-albumin (all, p < 0.001). Values of the ECM/BCM ratio ≥ 1.20 were associated with higher probability of all-cause mortality (p = 0.002). The ECM/BCM ratio ≥ 1.20, IL-6 ≥ 3.1 pg/mL, s-CRP and s-albumin ≥ 3.8 g/dL and Charlson index were significantly associated with all-cause mortality risk in multivariate adjusted analysis. This study demonstrates that the ECM/BCM ratio ≥ 1.20 as a nutritional marker and/or fluid overload indicator had a significant prognostic value of death risk in HD patients.

Rates of Cardiovascular Disease and CKD Progression in Young Adults with CKD across Racial and Ethnic Groups

Background

Significant racial and ethnic disparities in cardiovascular (CV) and kidney function outcomes in older adults with chronic kidney disease (CKD) have been reported. However, little is known about the extent to which these disparities exist in patients with CKD during the foundational period of young adulthood. The objective of this study was to determine risk factors and rates of CV disease and CKD progression in young adults with CKD across racial and ethnic groups.

Methods

We studied all participants aged 21-40 years of age enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study (n=317). Baseline CV risk factors were described across racial and ethnic groups.

Results

Outcomes included CV events or death (first incidence of heart failure, myocardial infarction, and stroke or death) and CKD progression (>50% decline in eGFR from baseline or end stage kidney disease [ESKD]). Incidence rate ratios (IRRs) were compared as a secondary analysis for participants identifying as Black or Hispanic with those identifying as White or another race and ethnicity. Adjusted models included age, sex, and per APOL1 high-risk allele. CV risk factors were higher in Black and Hispanic participants, including mean SBP, BMI, median UACr, and LDL. Black and Hispanic participants had higher incidence rates of HF (17.5 versus 5.1/1000 person-years), all-cause mortality (15.2 versus 7.1/1000 person-years), and CKD progression (125 versus 59/1000 person-years).

Conclusions

In conclusion, we found a higher prevalence of CV risk factors, some modifiable, in young adults with CKD who identify as Black or Hispanic. Future strategies to ameliorate the racial and ethnic inequality in health outcomes earlier in life for patients with CKD should be prioritized.

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.

Central versus ambulatory blood pressure for predicting mortality and cardiovascular events in hemodialysis patients: a multicenter cohort study

OBJECTIVE

Studies in the general population suggest that central blood pressure (BP) may be superior to peripheral BP in risk assessment. Although ambulatory brachial BP is recognized as the most reliable BP measurement in the dialysis population, there is no comparison of office central BP with ambulatory BP regarding risk stratification in these patients.

METHODS

In a multicenter prospective study of dialysis patients, central BP was measured noninvasively on a midweek nondialysis day, with interdialytic ambulatory BP and predialysis BP also collected. The primary outcomes were a composite of major adverse cardiovascular events (MACE) and all-cause mortality. Agreement between central and ambulatory BP was assessed using Cohen's Kappa index and Bland--Altman plot. Linear and nonlinear Cox regression models were used to determine the association of BP parameters with outcomes.

RESULTS

A total of 368 patients were recruited and 366 underwent central BP measurement. Central BP had a moderate agreement with ambulatory BP in defining hypertension (κ = 0.42) with wide limits of agreement in Bland--Altman analysis. After a median follow-up of 51.5 months, central pulse pressure, ambulatory SBP and ambulatory pulse pressure were associated with all-cause mortality, whereas all BP parameters, except for predialysis DBP, were significant predictors of MACE. However, whenever evaluated in a stepwise variable selection Cox model, only ambulatory pulse pressure, but not any central BP, was determined as the best candidate for prediction of both all-cause mortality and MACE. Nonlinear Cox models revealed no significant nonlinear trend of the association between central BP and outcomes.

CONCLUSION

Central BP is predictive of all-cause mortality and cardiovascular events in dialysis patients but its prognostic value does not outperform ambulatory peripheral BP. Our data support the superiority of ambulatory BP in the dialysis population.

The roles of sodium and volume overload on hypertension in chronic kidney disease

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular (CV) events, and the disease burden is rising rapidly. An important contributor to CV events and CKD progression is high blood pressure (BP). The main mechanisms of hypertension in early and advanced CKD are renin-angiotensin system activation and volume overload, respectively. Sodium retention is well known as a factor for high BP in CKD. However, a BP increase in response to total body sodium or volume overload can be limited by neurohormonal modulation. Recent clinical trial data favoring intensive BP lowering in CKD imply that the balance between volume and neurohormonal control could be revisited with respect to the safety and efficacy of strict volume control when using antihypertensive medications. In hemodialysis patients, the role of more liberal use of antihypertensive medications with the concept of functional dry weight for intensive BP control must be studied.

The dialysis facility levels and sizes are associated with outcomes of incident hemodialysis patients

The outcomes of patients with incident kidney failure who start hemodialysis are influenced by several factors. Whether hemodialysis facility characteristics are associated with patient outcomes is unclear. We included adults diagnosed as having kidney failure requiring hemodialysis during January 1, 2001 to December 31, 2013 from the Taiwan National Health Insurance Research Database to perform this retrospective cohort study. The exposures included different sizes and levels of hemodialysis facilities. The outcomes were all-cause mortality, cardiovascular death, infection-related death, hospitalization, and kidney transplantation. During 2001-2013, we identified 74,406 patients and divided them in to three groups according to the facilities where they receive hemodialysis: medical center (n = 8263), non-center hospital (n = 40,008), and clinic (n = 26,135). The multivariable Cox model demonstrated that a larger facility size was associated with a low mortality risk (hazard ratio [HR] 0.991, 95% confidence interval [95% CI] 0.984-0.998; every 20 beds per facility). Compared with medical centers, patients in non-center hospitals and clinics had higher mortality risks (HR 1.13, 95% CI 1.09-1.17 and HR 1.11, 95% CI 1.06-1.15, respectively). Patients in medical centers and non-center hospitals had higher risk of hospitalization (subdistribution HR [SHR] 1.11, 95% CI 1.10-1.12 and SHR 1.22, 95% CI 1.21-1.23, respectively). Patients in medical centers had the highest rate of kidney transplantation among the three groups. In patients with incident kidney failure, a larger hemodialysis facility size was associated with lower mortality. Overall, medical center patients had a lower mortality rate and higher transplantation rate, whereas clinic patients had a lower hospitalization risk.

Epidemiology of nursing home dialysis patients-A hidden population

Introduction

Dialysis patients are often discharged from hospitals to skilled nursing facilities (SNFs), but little has been published about their natural history.

Methods

Using electronic medical record data, we conducted a retrospective cohort study of nursing home patients treated with in‐SNF hemodialysis from January 1, 2018 through June 20, 2020 within a dialysis organization across eight states. A dialytic episode began with the first in‐SNF dialysis and was ended by hospitalization, death, transfer, or cessation of treatment. The clinical characteristics and natural history of these patients and their dialytic episodes are described.

Findings

Four thousand five hundred and ten patients experienced 9274 dialytic episodes. Dialytic episodes had a median duration of 18 days (IQR: 8–38) and were terminated by a hospitalization n = 5747 (62%), transfer n = 2638 (28%), death n = 568 (6%), dialysis withdrawal n = 129 (1.4%), recovered function n = 2 (0.02%), or other cause n = 6 (0.06%). Increased patient mortality was associated with advancing age, low serum creatinine, albumin, or sodium, and low pre‐dialytic systolic blood pressure (sBP). U‐shaped relationships to mortality were observed for intradialytic hypotension frequency and for post‐ > pre‐hemodialysis sBP frequency. Prescription of dialysis five times weekly in the first 2 weeks was associated with better survival in the first 90 days (HR 0.77, CI 0.62–0.96; p < 0.02).

Discussion

Provision of in‐SNF dialysis by an external dialysis organization enables discharge from the acute care setting for appropriate treatment with increased nursing contact time in an otherwise under‐resourced environment. SNF ESRD patient clinical characteristics and outcomes are extensively characterized for the first time.

Clinical significance of central systolic blood pressure in LV diastolic dysfunction and CV mortality

BACKGROUND AND AIMS

Cardiovascular (CV) disease is the major cause of death in patients with end-stage kidney disease (ESKD). Left ventricular (LV) diastolic dysfunction reflects LV pressure overload and is common in patients with ESKD. Recently, there have been studies on the usefulness of central blood pressure (BP); however, the relationship between central BP and LV diastolic dysfunction is not clear in dialysis patients with preserved systolic function. The purpose of this study was to investigate the clinical implication of central BP on LV diastolic dysfunction and CV mortality in the ESKD patients with preserved LV systolic function.

METHODS

This prospective observational cohort study investigated the effect of LV diastolic dysfunction on CV mortality in the ESKD patients with preserved systolic function using echocardiography. Vascular calcification was evaluated using the abdominal aortic calcification score, and aortic stiffness was determined by measuring pulse wave velocity (PWV). The predictors of CV mortality were analyzed using Cox proportional hazard analysis.

RESULTS

The subjects were comprised of 61 patients, with an average age of 54 years, 20 males (32.8%), and 25 diabetics (41.0%). There were 39 patients on hemodialysis and 22 patients receiving peritoneal dialysis treatment. During the mean follow-up period of 79.3 months, 16 patients (26.2%) died, and 7 patients (11.4%) died of CV events. The central systolic BP and diabetes were independent risk factors for LV diastolic dysfunction. In addition, patients with LV diastolic dysfunction had an increased CV mortality. When left atrial volume index and PWV were adjusted, the E/E' ratio was found to be a predictor of CV mortality.

CONCLUSIONS

Central systolic BP and diabetes were found to be significant risk factors for LV diastolic dysfunction. LV diastolic dysfunction can independently predict CV mortality in dialysis patients with preserved LV systolic function.

BP in Young Adults with CKD and Associations with Cardiovascular Events and Decline in Kidney Function

BACKGROUND

BP is an important modifiable risk factor for cardiovascular events and CKD progression in middle-aged or older adults with CKD. However, studies describing the relationship between BP with outcomes in young adults with CKD are limited.

METHODS

In an observational study, we focused on 317 young adults (aged 21-40 years) with mild to moderate CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Exposures included baseline systolic BP evaluated continuously (per 10 mm Hg increase) and in categories (<120, 120-129, and ≥130 mm Hg). Primary outcomes included cardiovascular events (heart failure, myocardial infarction, stroke, or all-cause death) and CKD progression (50% decline of eGFR or ESKD). We used Cox proportional hazard models to test associations between baseline systolic BP with cardiovascular events and CKD progression.

RESULTS

Cardiovascular events occurred in 52 participants and 161 had CKD progression during median follow-up times of 11.3 years and 4.1 years, respectively. Among those with baseline systolic BP ≥130 mm Hg, 3%/yr developed heart failure, 20%/yr had CKD progression, and 2%/yr died. In fully adjusted models, baseline systolic BP ≥130 mm Hg (versus systolic BP<120 mm Hg) was significantly associated with cardiovascular events or death (hazard ratio [HR], 2.13; 95% confidence interval [95% CI], 1.05 to 4.32) and CKD progression (HR, 1.68; 95% CI, 1.10 to 2.58).

CONCLUSIONS

Among young adults with CKD, higher systolic BP is significantly associated with a greater risk of cardiovascular events and CKD progression. Trials of BP management are needed to test targets and treatment strategies specifically in young adults with CKD.

Cardiopulmonary and metabolic physiology during hemodialysis and inter/intradialytic exercise

Hemodialysis is associated with numerous symptoms and side effects that, in part, may be due to subclinical hypoxia. However, acute cardiopulmonary and metabolic physiology during hemodialysis is not well defined. Intradialytic and interdialytic exercise appear to be beneficial and may alleviate these side effects. To better understand these potential benefits, the acute physiological response to exercise should be evaluated. The aim of this study was to compare and characterize the acute physiological response during hemodialysis, intradialytic exercise, and interdialytic exercise. Cardiopulmonary physiology was evaluated during three conditions: 1) hemodialysis without exercise (HD), 2) intradialytic exercise (IDEx), and 3) interdialytic exercise (Ex). Exercise consisted of 30-min constant load cycle ergometry at 90% V̇O₂AT (anaerobic threshold). Central hemodynamics (via noninvasive bioreactance) and ventilatory gas exchange were recorded during each experimental condition. Twenty participants (59 ± 12 yr, 16/20 male) completed the protocol. Cardiac output (Δ = -0.7 L/min), O₂ uptake (Δ = -1.4 mL/kg/min), and arterial-venous O₂ difference (Δ = -2.0 mL/O₂/100 mL) decreased significantly during HD. Respiratory exchange ratio exceeded 1.0 throughout HD and IDEx. Minute ventilation was lower (P = 0.001) during IDEx (16.5 ± 1.1 L/min) compared with Ex (19.8 ± 1.0 L/min). Arterial-venous O₂ difference was partially restored further to IDEx (4.6 ± 1.9 mL/O₂/100 mL) compared with HD (3.5 ± 1.2 mL/O₂/100 mL). Hemodialysis altered cardiopulmonary and metabolic physiology, suggestive of hypoxia. This dysregulated physiology contributed to a greater physiological demand during intradialytic exercise compared with interdialytic exercise. Despite this, intradialytic exercise partly normalized cardiopulmonary physiology during treatment, which may translate to a reduction in the symptoms and side effects of hemodialysis.NEW & NOTEWORTHY This study is the first, to our knowledge, to directly compare cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise, and interdialytic exercise. Hemodialysis was associated with increased respiratory exchange ratio, blunted minute ventilation, and impaired O₂ uptake and extraction. We also identified a reduced ventilatory response during intradialytic exercise compared with interdialytic exercise. Impaired arterial-venous O₂ difference during hemodialysis was partly restored by intradialytic exercise. Despite dysregulated cardiopulmonary and metabolic physiology during hemodialysis, intradialytic exercise was well tolerated.

Treating Home Versus Predialysis Blood Pressure Among In-Center Hemodialysis Patients: A Pilot Randomized Trial

RATIONALE & OBJECTIVE

Observational studies have reported a U-shaped association between blood pressure (BP) before a hemodialysis session and death. In contrast, because a linear association between out-of-dialysis-unit BP and death has been reported, home BP may be a better target for treatment. To test the feasibility of this approach, we conducted a pilot trial of treating home versus predialysis BP in hemodialysis patients.

STUDY DESIGN

A 4-month, parallel, randomized, controlled trial.

SETTINGS & PARTICIPANTS

50 prevalent hemodialysis patients in San Francisco and Seattle. Participants were randomly assigned using 1:1 block randomization, stratified by site.

INTERVENTIONS

To target home systolic BP (SBP) of 100-<140 mm Hg versus predialysis SBP of 100-<140mm Hg. Home and predialysis SBPs were ascertained every 2 weeks. Dry weight and BP medications were adjusted to reach the target SBP.

OUTCOMES

Primary outcomes were feasibility, adherence, safety. and tolerability.

RESULTS

50 of 70 (71%) patients who were approached agreed to participate. All enrollees completed the study except for 1 who received a kidney transplant. In the home BP treatment group, adherence to obtaining/reporting home BP was 97.4% (and consistent over the 4 months). There was no increased frequency of high (defined as SBP>200mm Hg; 0.2% vs 0%) or low (defined as<90mm Hg; 1.8% vs 1.2%) predialysis BP readings in the home versus predialysis treatment arms, respectively. However, participants in the home BP arm had higher frequency of fatigue (32% vs 16%).

LIMITATIONS

Small sample size.

CONCLUSIONS

This pilot trial demonstrates feasibility and high adherence to home BP measurement and treatment in hemodialysis patients. Larger trials to test the long-term feasibility, efficacy, and safety of home BP treatment in hemodialysis patients should be conducted.

FUNDERS

National Institutes of Health, Satellite Healthcare, and Northwest Kidney Centers.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT03459807.

Sodium, volume and pressure control in haemodialysis patients for improved cardiovascular outcomes

Chronic volume overload is pervasive in patients on chronic haemodialysis and substantially increases the risk of cardiovascular death. The rediscovery of the three-compartment model in sodium metabolism revolutionizes our understanding of sodium (patho-)physiology and is an effect modifier that still needs to be understood in the context of hypertension and end-stage kidney disease. Assessment of fluid overload in haemodialysis patients is central yet difficult to achieve, because traditional clinical signs of volume overload lack sensitivity and specificity. The highest all-cause mortality risk may be found in haemodialysis patients presenting with high fluid overload but low blood pressure before haemodialysis treatment. The second highest risk may be found in patients with both high blood pressure and fluid overload, while high blood pressure but normal fluid overload may only relate to moderate risk. Optimization of fluid overload in haemodialysis patients should be guided by combining the traditional clinical evaluation with objective measurements such as bioimpedance spectroscopy in assessing the risk of fluid overload. To overcome the tide of extracellular fluid, the concept of time-averaged fluid overload during the interdialytic period has been established and requires possible readjustment of a negative target post-dialysis weight. ²³Na-magnetic resonance imaging studies will help to quantitate sodium accumulation and keep prescribed haemodialytic sodium mass balance on the radar. Cluster-randomization trials (e.g. on sodium removal) are underway to improve our therapeutic approach to cardioprotective haemodialysis management.

Fluid and hemodynamic management in hemodialysis patients: challenges and opportunities

Fluid volume and hemodynamic management in hemodialysis patients is an essential component of dialysis adequacy. Restoring salt and water homeostasis in hemodialysis patients has been a permanent quest by nephrologists summarized by the ‘dry weight’ probing approach. Although this clinical approach has been associated with benefits on cardiovascular outcome, it is now challenged by recent studies showing that intensity or aggressiveness to remove fluid during intermittent dialysis is associated with cardiovascular stress and potential organ damage. A more precise approach is required to improve cardiovascular outcome in this high-risk population. Fluid status assessment and monitoring rely on four components: clinical assessment, non-invasive instrumental tools (e.g., US, bioimpedance, blood volume monitoring), cardiac biomarkers (e.g. natriuretic peptides), and algorithm and sodium modeling to estimate mass transfer. Optimal management of fluid and sodium imbalance in dialysis patients consist in adjusting salt and fluid removal by dialysis (ultrafiltration, dialysate sodium) and by restricting salt intake and fluid gain between dialysis sessions. Modern technology using biosensors and feedback control tools embarked on dialysis machine, with sophisticated analytics will provide direct handling of sodium and water in a more precise and personalized way. It is envisaged in the near future that these tools will support physician decision making with high potential of improving cardiovascular outcome.

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.

Blood pressure targets and pharmacotherapy for hypertensive patients on hemodialysis

INTRODUCTION

Hypertension is highly prevalent in patients with end-stage kidney disease on hemodialysis and is often not well controlled. Blood pressure (BP) levels before and after hemodialysis have a U-shaped relationship with cardiovascular and all-cause mortality. Although antihypertensive drugs are recommended for patients in whom BP cannot be controlled appropriately by non-pharmacological interventions, large-scale randomized controlled clinical trials are lacking.

AREAS COVERED

The authors review the pharmacotherapy used in hypertensive patients on dialysis, primarily focusing on reports published since 2000. An electronic search of MEDLINE was conducted using relevant key search terms, including 'hypertension', 'pharmacotherapy', 'dialysis', 'kidney disease', and 'antihypertensive drug'. Systematic and narrative reviews and original investigations were retrieved in our research.

EXPERT OPINION

When a drug is administered to patients on dialysis, the comorbidities and characteristics of each drug, including its dialyzability, should be considered. Pharmacological lowering of BP in hypertensive patients on hemodialysis is associated with improvements in mortality. β-blockers should be considered first-line agents and calcium channel blockers as second-line therapy. Renin-angiotensin-aldosterone system inhibitors have not shown superiority to other antihypertensive drugs for patients on hemodialysis.

Anesthetic Considerations for Patients on Renal Replacement Therapy

The number of patients presenting for surgery with renal dysfunction requiring renal replacement therapy (RRT) is expected to increase as the population ages and improvements in therapy continue to be made. Every aspect of the perioperative period is affected by renal dysfunction, its associated comorbidities, and altered physiology secondary to RRT. Most alarming is the increased risk for perioperative cardiac morbidity and mortality seen in this population. Perioperative optimization and management aims to minimize these risks; however, few definite guidelines on how to do so exist.

The relationship of volume overload and its control to hypertension in hemodialysis patients

Hypertension is highly prevalent and associated with poor clinical outcomes among individuals receiving maintenance hemodialysis (HD). Volume overload is a key modifiable contributor to hypertension and cardiovascular disease in the HD population. Despite their importance, assessment and treatment of volume overload and hypertension remain major clinical challenges and have substantial implications for both clinical outcomes and patient experiences of care. This review will summarize current data on the diagnosis, epidemiology, pathophysiology, and clinical consequences of hypertension and volume overload in HD patients. We will also identify priorities for future research studies.

Systolic and diastolic hypertension among patients on hemodialysis: Musings on volume overload, arterial stiffness, and erythropoietin

Hypertension among patients on hemodialysis is predominantly systolic (either isolated or combined with diastolic hypertension), whereas the scenario of isolated diastolic hypertension is rare and more common in younger patients. Uncontrolled hypertension that persists despite aggressive antihypertensive drug therapy is a reflection of the volume overload that is a prominent mediator of systolic and diastolic BP elevation. Clinical-trial evidence supports the notion that dry-weight probing is an effective strategy to improve BP control, even when overt clinical signs and symptoms of volume overload are not present. Accelerated arterial stiffness influences the patterns and rhythms of interdialytic ambulatory BP and is a major determinant of isolated systolic hypertension in hemodialysis. Posthoc analyses of the Hypertension in Hemodialysis patients treated with Atenolol or Lisinopril (HDPAL) trial, however, suggest that arterial stiffness does not make hypertension more resistant to therapy and is unable to predict the treatment-induced improvement in left ventricular hypertrophy. A combined strategy of sodium restriction, dry-weight adjustment, and antihypertensive medication use was effective in improving ambulatory BP control regardless of the severity of underlying arteriosclerosis in HDPAL. Other nonvolume-dependent mechanisms, such as erythropoietin use, appear to be also important contributors and should be taken into consideration, particularly in younger hemodialysis patients with diastolic hypertension. In this article, we explore the role of volume overload, arterial stiffness, and erythropoietin use as causes of systolic vs diastolic hypertension in patients on hemodialysis. We conclude with clinical practice recommendations and with a call for a "volume-first" approach when managing hemodialysis hypertension.

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

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

Blood pressure control in conventional hemodialysis

Hypertension among patients on hemodialysis is common, difficult to diagnose and often inadequately controlled. Although specific blood pressure (BP) targets in this particular population are not yet established, meta-analyses of randomized trials showed that deliberate BP-lowering with antihypertensive drugs improves clinical outcomes in hemodialysis patients. BP-lowering in these individuals should initially utilize nonpharmacological strategies aiming to control sodium and volume overload. Accordingly, restricting dietary sodium intake, eliminating intradialytic sodium gain via individualized dialysate sodium prescription, optimally assessing and managing dry-weight and providing a sufficient duration of dialysis are first-line treatment considerations to control BP. If BP remains uncontrolled despite the adequate management of volume, antihypertensive therapy is the next consideration. Contrary to nonhemodialysis populations, emerging clinical-trial evidence suggests that among those on hemodialysis, β-blockers are more effective than agents blocking the renin-angiotensin-system (RAS) in reducing BP levels and protecting from serious adverse cardiovascular complications. Accordingly, β-blockade is our first-line approach in pharmacotherapy of hypertension. Long-acting calcium-channel-blockers and RAS-blockers are our next considerations, taking into account the comorbidities and the overall risk profile of each individual patient. Additional research efforts, mainly randomized trials, are clearly warranted in order to elucidate aspects of management that remain elusive in hypertensive dialysis patients.

Evolution of Echocardiographic Measures of Cardiac Disease From CKD to ESRD and Risk of All-Cause Mortality: Findings From the CRIC Study

RATIONALE & OBJECTIVE

Abnormal cardiac structure and function are common in chronic kidney disease (CKD) and end-stage renal disease (ESRD) and linked with mortality and heart failure. We examined changes in echocardiographic measures during the transition from CKD to ESRD and their associations with post-ESRD mortality.

STUDY DESIGN

Prospective study.

SETTING & PARTICIPANTS

We studied 417 participants with CKD in the Chronic Renal Insufficiency Cohort (CRIC) who had research echocardiograms during CKD and ESRD.

PREDICTOR

We measured change in left ventricular mass index, left ventricular ejection fraction (LVEF), diastolic relaxation (normal, mildly abnormal, and moderately/severely abnormal), left ventricular end-systolic (LVESV), end-diastolic (LVEDV) volume, and left atrial volume from CKD to ESRD.

OUTCOMES

All-cause mortality after dialysis therapy initiation.

ANALYTICAL APPROACH

Cox proportional hazard models were used to test the association of change in each echocardiographic measure with postdialysis mortality.

RESULTS

Over a mean of 2.9 years between pre- and postdialysis echocardiograms, there was worsening of mean LVEF (52.5% to 48.6%; P<0.001) and LVESV (18.6 to 20.2mL/m2.7; P<0.001). During this time, there was improvement in left ventricular mass index (60.4 to 58.4g/m2.7; P=0.005) and diastolic relaxation (11.11% to 4.94% with moderately/severely abnormal; P=0.02). Changes in left atrial volume (4.09 to 4.15mL/m2; P=0.08) or LVEDV (38.6 to 38.4mL/m2.7; P=0.8) were not significant. Worsening from CKD to ESRD of LVEF (adjusted HR for every 1% decline in LVEF, 1.03; 95% CI, 1.00-1.06) and LVESV (adjusted HR for every 1mL/m2.7 increase, 1.04; 95% CI, 1.02-1.07) were independently associated with greater risk for postdialysis mortality.

LIMITATIONS

Some missing or technically inadequate echocardiograms.

CONCLUSIONS

In a longitudinal study of patients with CKD who subsequently initiated dialysis therapy, LVEF and LVESV worsened and were significantly associated with greater risk for postdialysis mortality. There may be opportunities for intervention during this transition period to improve outcomes.

Hemodynamic Instability during Dialysis: The Potential Role of Intradialytic Exercise

Acute haemodynamic instability is a natural consequence of disordered cardiovascular physiology during haemodialysis (HD). Prevalence of intradialytic hypotension (IDH) can be as high as 20–30%, contributing to subclinical, transient myocardial ischemia. In the long term, this results in progressive, maladaptive cardiac remodeling and impairment of left ventricular function. This is thought to be a major contributor to increased cardiovascular mortality in end stage renal disease (ESRD). Medical strategies to acutely attenuate haemodynamic instability during HD are suboptimal. Whilst a programme of intradialytic exercise training appears to facilitate numerous chronic adaptations, little is known of the acute physiological response to this type of exercise. In particular, the potential for intradialytic exercise to acutely stabilise cardiovascular hemodynamics, thus preventing IDH and myocardial ischemia, has not been explored. This narrative review aims to summarise the characteristics and causes of acute haemodynamic instability during HD, with an overview of current medical therapies to treat IDH. Moreover, we discuss the acute physiological response to intradialytic exercise with a view to determining the potential for this nonmedical intervention to stabilise cardiovascular haemodynamics during HD, improve coronary perfusion, and reduce cardiovascular morbidity and mortality in ESRD.