Diagnostic potential of cardiac natriuretic peptides in dialysis patients

Association of frequent intradialytic hypotension with the clinical outcomes of patients on hemodialysis: a prospective cohort study

Intradialytic hypotension (IDH) is a common complication of hemodialysis (HD), but there is no consensus on its definition. In 2015, Flythe proposed a definition of IDH (Definition 1 in this study): nadir systolic blood pressure (SBP) <90 mmHg during hemodialysis for patients with pre-dialysis SBP <159 mmHg, and nadir SBP <100 mmHg during hemodialysis for patients with pre-dialysis SBP ≥160 mmHg. This prospective observational cohort study investigated the association of frequent IDH based on Definition 1 with clinical outcomes and compared Definition 1 with a commonly used definition (nadir SBP <90 mmHg during hemodialysis, Definition 2). The incidence of IDH was observed over a 3-month exposure assessment period. Patients with IDH events ≥30% were classified as 'frequent IDH'; the others were 'infrequent IDH'. All-cause mortality, cardiovascular mortality, and all-cause hospitalization events were followed up for 36 months. This study enrolled 163 HD patients. The incidence of IDH was 11.1% according to Definition 1 and 10.5% according to Definition 2. The Kaplan-Meier curves showed that frequent IDH patients had higher risks of all-cause mortality (p = 0.009, Definition 1; p = 0.002, Definition 2) and cardiovascular mortality (p = 0.021, Definition 1). Multivariable Cox regression analysis indicated that frequent IDH was independently associated with a higher risk of all-cause mortality (Model 1: HR = 2.553, 95%CI 1.334-4.886, p = 0.005; Model 2: HR = 2.406, 95%CI 1.253-4.621, p = 0.008). In conclusion, HD patients classified as frequent IDH are at a greater risk of all-cause mortality. This highlights the significance of acknowledging and proactively managing frequent IDH within the HD patients.

Cardiomyopathy in chronic kidney disease: clinical features, biomarkers and the contribution of murine models in understanding pathophysiology

The cardiorenal syndrome (CRS) is described as a multi-organ disease encompassing bidirectionally heart and kidney. In CRS type 4, chronic kidney disease (CKD) leads to cardiac injury. Different pathological mechanisms have been identified to contribute to the establishment of CKD-induced cardiomyopathy, including a neurohormonal dysregulation, disturbances in the mineral metabolism and an accumulation of uremic toxins, playing an important role in the development of inflammation and oxidative stress. Combined, this leads to cardiac dysfunction and cardiac pathophysiological and morphological changes, like left ventricular hypertrophy, myocardial fibrosis and cardiac electrical changes. Given that around 80% of dialysis patients suffer from uremic cardiomyopathy, the study of cardiac outcomes in CKD is clinically highly relevant. The present review summarizes clinical features and biomarkers of CKD-induced cardiomyopathy and discusses underlying pathophysiological mechanisms recently uncovered in the literature. It discloses how animal models have contributed to the understanding of pathological kidney-heart crosstalk, but also provides insights into the variability in observed effects of CKD on the heart in different CKD mouse models, covering both "single hit" as well as "multifactorial hit" models. Overall, this review aims to support research progress in the field of CKD-induced cardiomyopathy.

Natriuretic Peptides: It Is Time for Guided Therapeutic Strategies Based on Their Molecular Mechanisms

Natriuretic peptides (NPs) are the principal expression products of the endocrine function of the heart. They exert several beneficial effects, mostly mediated through guanylate cyclase-A coupled receptors, including natriuresis, diuresis, vasorelaxation, blood volume and blood pressure reduction, and regulation of electrolyte homeostasis. As a result of their biological functions, NPs counterbalance neurohormonal dysregulation in heart failure and other cardiovascular diseases. NPs have been also validated as diagnostic and prognostic biomarkers in cardiovascular diseases such as atrial fibrillation, coronary artery disease, and valvular heart disease, as well as in the presence of left ventricular hypertrophy and severe cardiac remodeling. Serial measurements of their levels may be used to contribute to more accurate risk stratification by identifying patients who are more likely to experience death from cardiovascular causes, heart failure, and cardiac hospitalizations and to guide tailored pharmacological and non-pharmacological strategies with the aim to improve clinical outcomes. On these premises, multiple therapeutic strategies based on the biological properties of NPs have been attempted to develop new targeted cardiovascular therapies. Apart from the introduction of the class of angiotensin receptor/neprilysin inhibitors to the current management of heart failure, novel promising molecules including M-atrial natriuretic peptide (a novel atrial NP-based compound) have been tested for the treatment of human hypertension with promising results. Moreover, different therapeutic strategies based on the molecular mechanisms involved in NP regulation and function are under development for the management of heart failure, hypertension, and other cardiovascular conditions.

NT-proBNP as predictor of major cardiac events after renal transplantation in patients with preserved left ventricular ejection fraction

BACKGROUND

For the improvement of outcome after renal transplantation it is important to predict future risk of major adverse cardiac events as well as all-cause mortality. We aimed to determine the relationship of pre-transplant NT-proBNP with major adverse cardiac events and all-cause mortality after transplant in patients on the waiting-list with preserved left ventricular ejection fraction.

PATIENTS AND METHODS

We included 176 patients with end-stage renal disease and preserved left ventricular ejection fraction who received a kidney transplant. MACE was defined as myocardial infarction (ST-segment elevation [STEMI] or non-ST-segment elevation [NSTEMI]), stroke or transient ischemic attack), coronary artery disease requiring intervention or bypass or death from cardiovascular causes.

RESULTS

MACE occurred in 28/176 patients. Patients with NT-proBNP levels above 4350 pg/ml had 1- and 5-year survival rates of 90.67% and 68.20%, whereas patients with NT-proBNP levels below 4350 pg/ml had 1- and 5-year survival rates of 100% and 90.48% (p < 0.01). 1- and 5-year MACE-free survival rates were calculated as 78.82% and 74.68% for patients with NT-proBNP > 4350 pg/ml and 93.33% and 91.21% for patients with NT-proBNP < 4350 pg/ml (p < 0.01).

CONCLUSIONS

Pre-transplant NT-proBNP might identify renal transplant candidates at risk for MACE after transplant.

Association between subclinical left ventricular ejection fraction and platelet-to-lymphocyte ratio in patients with peritoneal dialysis

Background

Reduced left ventricular ejection function (LVEF) was associated with increased mortality in patients with peritoneal dialysis (PD) in Asia and the United States of America. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were correlated with LVEF in PD. However, little information is available regarding the relationship between monocyte-to-lymphocyte ratio (MLR), left ventricular ejection fraction (LVEF), and the use of NLR, PLR, and MLR in predicting left ventricular systolic dysfunction (LVSD) in patients with PD.

Methods

All 181 patients with PD were enrolled between 2014 and 2021 from the Nephrology Department of the First Affiliated Hospital of the University of South China. Demographic features, clinical characteristics, laboratory values, and echocardiographic parameters were collected.

Results

The mean age of patients with PD was 47.4 ± 12.6, and 90 (49.7%) of the patients were men. LVEF showed a negative correlation with PLR (r = −0.200, p = 0.007) and MLR (r = −0.146, p = 0.049). The levels of NLR, PLR, and MLR were elevated in patients with PD with LVSD compared with those without (all p &lt; 0.05). PLR (OR 4.331, 95% CI: 1.223, 15.342) and albumin (OR 13.346, 95% CI: 3.928, 45.346) were significantly associated with LVSD patients with PD in the multivariate logistic analysis. For differentiating patients with PD with LVSD, optimal cutoffs of NLR, PLR, MLR, and albumin were 4.5 (sensitivity: 76.7%, specificity: 55.0%, and overall accuracy: 58%), 202.6 (sensitivity: 66.7%, specificity: 69.5%, and overall accuracy: 69%), 0.483 (sensitivity: 53.3%, specificity: 72.8%, and overall accuracy: 30%), and 34.6 (sensitivity: 72.2%), respectively.

Conclusions

Our results revealed that PLR was better than NLR, MLR, and albumin in predicting LVSD in PD.

Brain Natriuretic Peptide (BNP) Affects Growth and Stress Tolerance of Representatives of the Human Microbiome, Micrococcus luteus C01 and Alcaligenes faecalis DOS7

Simple Summary

The body of an average person weighing 70 kg contains approximately 39 trillion bacterial cells, which densely inhabit the gastrointestinal tract, skin, mucous membranes, etc. Bacteria respond to the signaling molecules in the human body, regulate the expression of the necessary genes, and thus adapt to the physiology of the host. Signaling molecules include hormones, neurotransmitters, immune system molecules, as well as natriuretic peptides, which are involved in the regulation of the circulatory system, water and electrolyte metabolism, and adipose tissue metabolism. Brain natriuretic peptide (BNP) is secreted by the ventricles during congestion and signals heart failure. This study showed that the presence of BNP in the growth medium of human symbiont bacteria affects their growth characteristics, survival, and stress resistance, including antibiotic resistance. It was concluded that bacterial populations that develop in a healthy person at a BNP level of up to 250 pg/mL will be more stress resistant than in a person suffering from heart failure. Our findings are promising to be used both in clinical medical practice and in the production of bacterial preparations for cosmetology, agriculture, and waste management.

Abstract

Brain natriuretic peptide (BNP) is secreted by the ventricles of the heart during overload to signal heart failure. Slight bilateral skin itching induced by BNP has been associated with response activity of the skin microbiota. In this work, we studied the effect of 25–250,000 pg BNP/mL on the growth, long-term survival, and stress (H₂O₂, antibiotics, salinity, heat and pH shock) resistance of human symbiont bacteria: Gram-positive Micrococcus luteus C01 and Gram-negative Alcaligenes faecalis DOS7. The effect of BNP turned out to be dose-dependent. Up to 250 pg BNP/mL made bacteria more stress resistant. At 2500 pg BNP/mL (heart failure) the thermosensitivity of the bacteria increased. Almost all considered BNP concentrations increased the resistance of bacteria to the action of tetracycline and ciprofloxacin. Both bacteria survived 1.3–1.7 times better during long-term (up to 4 months) storage. Our findings are important both for clinical medical practice and for practical application in other areas. For example, BNP can be used to obtain stress-resistant bacteria, which is important in the collection of microorganisms, as well as for the production of bacterial preparations and probiotics for cosmetology, agriculture, and waste management.

Global longitudinal strain is superior to ejection fraction for detecting myocardial dysfunction in end-stage renal disease with hyperparathyroidism

BACKGROUND

The estimation of left ventricular ejection fraction (LVEF) by 2D echocardiography (2D-ECHO) is the most used tool to assess LV systolic function (LVSF). Global longitudinal strain (GLS) has recently been suggested as a superior method for several evaluations. This study explored the association and prevalence of LV systolic dysfunction (LVSD) by using these methods in patients with end-stage renal disease (ESRD) and severe hyperparathyroidism (SHPTH); both associated with cardiovascular events (CEs).

AIM

To evaluate the myocardial function in patients with ESRD and SHPTH by using the GLS and LVEF measured through conventional 2D-ECHO.

METHODS

In 62 patients with ESRD and SHPTH, asymptomatic, and without a history of CEs, LVSF was evaluated by 2D-ECHO, obtaining the EF, by the Simpson biplane method, and GLS by speckle tracking.

RESULTS

The total patients with ESRD had a preserved LVEF (> 50%) but abnormal GLS (< 13.55%). Additionally, multivariate analysis showed an independent association of GLS and serum parathyroid hormone (PTH), LV mass index, and hemoglobin. Also, PTH was independently associated with lateral e' wave and tricuspid regurgitation velocity.

CONCLUSION

In patients with SHPTH linked to ESRD, the use of GLS by 2D-ECHO is a more sensitive tool than LVEF for detecting LVSD.

Do Natriuretic Peptide Measurements Provide Insights into Management of End-Stage Renal Disease Patients Undergoing Dialysis?

PURPOSE OF REVIEW

Impaired renal function may affect natriuretic peptide levels through a variety of factors and mechanisms, such as high prevalence of concomitant vascular and myocardial diseases, reduced clearance, increased risk of volume overload, and different types and solute removal techniques in the setting of dialysis. Nevertheless, accumulating evidence suggests that natriuretic peptide testing may provide insights into management of patients with chronic kidney disease (CKD) and end-stage kidney disease (ESRD) on dialysis, as they have been shown to be independently associated with morbidity and mortality.

RECENT FINDINGS

Rising natriuretic peptide levels over time may identify CKD patients more likely to approach ESRD and requiring dialysis initiation. Moreover, serial natriuretic peptide measurements may also be helpful in guiding fluid management in ESRD patients on dialysis. However, since patients with CKD usually have significantly higher and more variable baseline levels of natriuretic peptides than those without CKD, traditional cut-off values may not be applicable, and individualized trajectories should be applied and interpreted in the clinical context. Routine clinical use natriuretic peptide testing in the CKD and ESRD settings still needs to be refined and individualized, yet their diagnostic and prognostic values can provide valuable insights into clinical trajectories and potential treatment responses.

Range of plasma brain natriuretic peptide (BNP) levels in hemodialysis patients at a high risk of 1-year mortality and their relationship with the nutritional status: a retrospective cohort study in one institute

Background

Brain natriuretic peptide (BNP) levels are used as a marker of heart failure, which is the leading cause of morbidity and mortality in dialysis patients. BNP levels increase as renal function declines. The range of BNP levels associated with satisfactory longevity in dialysis patients currently remains unknown.

Methods

In total, 660 patients receiving maintenance hemodialysis were enrolled. BNP levels were measured at the end of the year and in a follow-up to assess 1-year mortality between 2008 and 2012. Patients were divided into six groups according to BNP levels: < 50 (reference), 50 to < 100, 100 to < 300, 300 to < 500, 500 to < 1000, and ≥ 1000 pg/mL. One-year mortality at each BNP level was analyzed using Cox’s proportional hazards model after adjustments for confounding factors.

Results

During the follow-up period, 78 (11.8%) deaths were recorded. After adjustments for confounding factors, such as gender, age, hemodialysis vintage, and primary disease, the risk of 1-year mortality was significantly high with BNP levels of 500 to < 1000 (hazard ratio [HR] 3.010; 95% confidence interval [CI] 1.065–10.729; P = 0.037) and more than 1000 pg/mL (HR 5.291; 95%CI 2.014–18.170; P = 0.0003). After adjustments for Kt/V, the risk of 1-year mortality was also significantly high with BNP levels of 500 to < 1000 (HR 3.045; 95%CI 1.065–10.929; P = 0.037) and more than 1000 pg/mL (HR 5.221; 95%CI 1.943–18.165; P = 0.0006). Following further adjustments for nutritional factors, such as albumin levels, total cholesterol levels, the normalized protein catabolic rate (nPCR), body mass index (BMI), and percent creatinine generation rate (%CGR), BNP levels of 500–1000 (HR 1.990; 95%CI 0.639–7.570; P = 0.244), and more than 1000 pg/mL (HR 2.100; 95%CI 0.663–8.105; P = 0.213) were no longer risk factors.

Conclusion

In dialysis patients, a BNP level ≥ 500 pg/mL is a risk factor for 1-year mortality. The risk associated with high BNP levels is reduced by nutritional factors, which suggests a relationship between high BNP levels and the nutritional status. In conclusion, efforts are needed to maintain BNP levels at lower than 500 pg/mL and improve the nutritional status.

Upstroke Time as a Novel Predictor of Mortality in Patients with Chronic Kidney Disease

Upstroke time (UT), measured from the foot-to-peak peripheral pulse wave, is a merged parameter used to assess arterial stiffness and target vascular injuries. In this study, we aimed to investigate UT for the prediction of cardiovascular and all-cause mortality in patients with chronic kidney disease (CKD). This longitudinal study enrolled 472 patients with CKD. Blood pressure, brachial pulse wave velocity (baPWV), and UT were automatically measured by a Colin VP-1000 instrument. During a median follow-up of 91 months, 73 cardiovascular and 183 all-cause mortality instances were recorded. Multivariable Cox analyses indicated that UT was significantly associated with cardiovascular mortality (hazard ratio (HR) = 1.010, p = 0.007) and all-cause mortality (HR = 1.009, p < 0.001). The addition of UT into the clinical models including traditional risk factors and baPWV further increased the value in predicting cardiovascular and all-cause mortality (both p < 0.001). In the Kaplan–Meier analyses, UT ≥ 180 ms could predict cardiovascular and all-cause mortality (both log-rank p < 0.001). Our study found that UT was a useful parameter in predicting cardiovascular and all-cause mortality in CKD patients. Additional consideration of the UT might provide an extra benefit in predicting cardiovascular and all-cause mortality beyond the traditional risk factors and baPWV.

Pathophysiology and significance of natriuretic peptides in patients with end-stage kidney disease

Natriuretic peptides (NP), especially B type (BNP) and its N-terminal pro-B type natriuretic peptide (NT-proBNP), have long been regarded as biomarkers of volume overload and tools to exclude heart failure in the general population. However, their role in end-stage kidney disease (ESKD) is less certain given that BNP and NT-proBNP are excreted by the kidney and so serum concentrations of NPs are nearly universally elevated compared to controls. Nevertheless, the accumulated evidence suggests thatserum concentrations of NPs in patients with ESKD show moderate or strong positive relationships with underlying heart disease, abnormal cardiac structure or function and mortality. Limited evidence also supports the role of BNP including NT-proBNP, ANP in some studies, rather than CNP or DNP in risk stratification among ESKD patients as well as the utility of BNP samplings pre- and post- hemodialysis. However, studies of the cut-off values of NPs have yielded inconsistent results, such that further large-scale studies are needed to clarify these issues. This review summarizes the pathophysiology and significance of NPs in ESKD patients, especially their potential role as risk stratification biomarkers in clinical management.

Soluble CD146 and B-type natriuretic peptide dissect overhydration into functional components of prognostic relevance in haemodialysis patients

Background

Accurate volume status evaluation and differentiation of cardiac and non-cardiac components of overhydration (OH) are fundaments of optimal haemodialysis (HD) management.

Methods

This study, by combining bioimpedance measurements, cardiovascular biomarkers and echocardiography, aimed at dissecting OH into its major functional components, and prospectively tested the association between cardiac and non-cardiac components of OH with mortality. In the first part, we validated soluble CD146 (sCD146) as a non-cardiac biomarker of systemic congestion in a cohort of 30 HD patients. In the second part, we performed a prospective 1-year follow-up study in an independent cohort of 144 HD patients.

Results

sCD146 incrementally increased after the short and long intervals after HD (+53 ng/mL, P = 0.006 and  +91 ng/mL, P < 0.001), correlated with OH as determined by bioimpedance and well-diagnosed OH (area under the receiver operating characteristics curve 0.72, P = 0.005). The prevalence of OH was lower for low-sCD146 and low-BNP patients (B-type natriuretic peptide, 29%) compared with subjects with either one or both biomarkers elevated (65-74%, P < 0.001). Notably, most low-BNP but high-sCD146 subjects were overhydrated. Systolic dysfunction was 2- to 3-fold more prevalent among high-BNP compared with low-BNP patients (44-68% versus 21-23%, chi-square P < 0.001), regardless of sCD146. One-year all-cause mortality was markedly higher in patients with high-BNP (P = 0.001) but not with high-sCD146. In multivariate analysis, systolic dysfunction and BNP, but not OH, were associated with lower survival.

Conclusions

The combination of BNP and sCD146 dissects OH into functional components of prognostic value. OH in HD patients is associated with higher mortality only if resulting from cardiac dysfunction.

Cardiorenal Interactions Revisited: How to Improve Heart Failure Outcomes in Patients With Chronic Kidney Disease

PURPOSE OF THE REVIEW

To summarize current advances in the understanding and management of heart failure (HF) in patients with advanced chronic kidney disease (CKD).

RECENT FINDINGS

Diagnosis of HF and treatment of congestion are crucial in the management of patients with advanced CKD to reduce symptoms, preserve organ function, and improve outcomes. Echocardiography and cardiovascular biomarkers may help to differentiate cardiac from non-cardiac components of overhydration. Renal replacement therapy or ultrafiltration may be required to treat congestion. Furthermore, patients with advanced CKD are frequently undertreated with disease-modifying HF therapies, but the use of beta-blockers and ACEi should be considered under close monitoring of kidney function and serum potassium. The use of the new oral potassium binders may translate into improved outcomes. The treatment of HF in patients with advanced CKD requires a multi-disciplinary approach. New diagnostic and therapeutic strategies are under evaluation and may contribute to improved outcomes.

Role of the Soluble Receptor for Advanced Glycation End Products (sRAGE) as a Prognostic Factor for Mortality in Hemodialysis and Peritoneal Dialysis Patients

End-stage renal disease patients on dialysis (CKD-G5D) have a high mortality rate due to cardiovascular diseases (CVD). In these patients, inflammation, oxidative stress, and uremia increase the production of glycation products (AGEs) which in turn accelerate CVD onset and progression. Recently, attention has been given to the soluble receptor for AGEs (sRAGE) as a marker of inflammation, oxidative stress, atherosclerosis, and heart failure in CKD-G5D. However, its association with patient outcomes is still under debate. Our aim is to explore whether sRAGE may be a predictor of mortality in CKD-G5D. We studied 123 CKD-G5D for 24 months. Of these patients, 56 were on hemodialysis (HD) and 67 on peritoneal dialysis (PD). Demographic, anthropometric, biochemical, and clinical data were recorded. sRAGE was quantified by enzyme-linked immunosorbent assay. sRAGE was a predictor of mortality at 2-year follow-up. Each increase of 100 pg/mL in sRAGE levels was associated with an approximately 7% increased risk of mortality. Furthermore, in the entire study group, as well as in PD and HD patient subgroups, sRAGE was positively correlated with brain natriuretic peptide (BNP) levels. Mortality rates as well as sRAGE levels in patients who died did not differ between PD and HD patients. In conclusion, the positive association observed with BNP levels suggests a role for sRAGE as a prognostic factor for mortality in CKD-G5D patients displaying an active process of cardiac remodeling.

Predictive abilities of baseline measurements of fluid overload, assessed by bioimpedance spectroscopy and serum N-terminal pro-B-type natriuretic peptide, for mortality in hemodialysis patients

INTRODUCTION

Fluid overload is one of the most important, yet modifiable, risk factors associated with worse outcomes in hemodialysis (HD) patients. However, its precise assessment in clinical practice is still under investigation.

MATERIAL AND METHODS

This is an observational prospective study which included 285 stable patients with end-stage renal disease on standard thrice-weekly HD therapy. Overhydration was assessed by the combination of relative fluid overload (RFO), using bioimpedance spectroscopy, and N-terminal pro-B-type natriuretic peptide (NT-proBNP). The outcome of interest was all-cause mortality.

RESULTS

The median values for NT-proBNP and RFO were 4595 pg/ml and 6.9%, respectively. We divided the study population into four groups according to these median levels: group 1 - low NT-proBNP and low RFO; group 2 - high NT-proBNP and low RFO; group 3 - low NT-proBNP and high RFO; group 4 - high NT-proBNP and high RFO. During the follow-up (mean: 41.1, median: 48.7 months), 89 (31.2%) patients died. In the univariable Cox survival analysis only patients in group 4, and not those from group 2 or 3, had significantly higher HRs as compared to those in group 1 (HR = 1.5, 95% CI: 0.8-2.8, HR = 1.6, 95% CI: 0.8-2.9 and HR = 2.4, 95% CI: 1.3-4.2, for group 2, 3 and 4, respectively). Furthermore, these results were maintained in the multivariable Cox analysis.

CONCLUSIONS

Including both bioimpedance and NT-proBNP monitoring in a more comprehensive fluid status assessment could improve the diagnosis of fluid overload with a final improvement in patients' outcome.

Hypomagnesemia and cause-specific mortality in hemodialysis patients: 5-year follow-up analysis

INTRODUCTION

The aim of this prospective study was to evaluate the association between serum magnesium (Mg) and mortality, in particular the cause-specific mortality of Mg and other risk factors in hemodialysis (HD) patients.

METHODS

We studied a cohort of 185 HD patients receiving thrice-weekly HD treatment, on a dialysate Mg concentration of 0.5 mmol/L. We stratified 3 patient groups according to the level of Mg: lower (<1.1 mmol/L), intermediate-reference (1.1 to <1.3 mmol/L), and higher (Mg >1.3 mm/L).

RESULTS

During the 5-year follow-up, 60 patients died, with cardiovascular (CV) disease as the predominant cause (73.3%). Hazard ratio (HR) for all-cause and CV mortality were 2.55 and 2.67 in the lower versus intermediate Mg group, but there was no significant association between the higher and intermediate Mg group. Univariate Cox regression analysis showed that Mg <1.1 versus 1.1-1.30 mml/L with HR 2.34, was a significant univariate predictor for increased mortality in addition to the Hb <110 g/L, Alb <40 g/L, C-reactive protein (CRP) ≥10 mg/L and brain natriuretic peptide >1,200 pg/mL. However, in the multivariate analysis only CRP ≥10 mg/L with HR 3.89 was a significant predictor of mortality. Subgroup analyses showed that among patients with CRP >10 mg/L, HR for all-cause and CV mortality of the lower versus intermediate Mg group were 1.96 and 2.39, respectively, not reaching significance for the higher versus intermediate Mg group. Conversely, there was no association between Mg level and all-cause and CV mortality within these 3 groups among patients with CRP <10 mg/L.

CONCLUSIONS

Lower serum Mg level was significantly associated with an increased all-cause and cardiovascular mortality in HD patients, especially in inflamed patients.

Cardiac biomarkers in dialysis

Cardiovascular disease is the major cause of death, accounting for approximately 40 percent of all-cause mortality in patients receiving either hemodialysis or peritoneal dialysis. Cardiovascular risk stratification is an important aspect of managing dialysis patients as it enables early identification of high-risk patients, so therapeutic interventions can be optimized to lower cardiovascular morbidity and mortality. Biomarkers can detect early stages of cardiac injury so timely intervention can be provided. The B-type natriuretic peptides (Brain Natriuretic peptide [BNP] and N-terminal pro-B-type natriuretic peptide [NT-proBNP]) and troponins have been shown to predict mortality in dialysis patients. Suppression of tumorigenicity 2 (ST2) and galectin-3 are new emerging biomarkers in the field of heart failure in both the general and dialysis populations. This article aims to discuss the current evidence regarding cardiac biomarker use to diagnose myocardial injury and monitor the risk of major adverse cardiovascular events in patients undergoing dialysis.

Impact of vascular access intervention therapy on cardiac load in hemodialysis patients

Vascular access intervention therapy (VAIVT) has been positioned as the first choice of treatment for stenosis lesions frequently observed in arteriovenous fistula (AVF) for hemodialysis patients in Japan. Furthermore, increased blood flow can provide a stable dialysis. In contrast, it has been reported that excess blood flow of AVF causes high-output heart failure. Although VAIVT is used to increase blood flow of AVF, the impact of VAIVT on cardiac load has been rarely reported. We examined the factors associated with cardiac load in hemodialysis patients undergoing VAIVT by measuring levels of α human atrial natriuretic polypeptide (hANP) and brain natriuretic peptide (BNP) before and after VAIVT. Data were extracted on hemodialysis patients who underwent measurements of αhANP and BNP in before and after VAIVT at our facility and related facilities between February 2014 and December 2014. Nineteeen patients (median age, 73.0 [66.5-80.5] years; male, 52.6%; 36.8% with diabetes; median duration of dialysis treatment, 50.0 [21-109] months) were enrolled in this study. Flow volume of AVF was higher after VAIVT than that before VAIVT (442.0 vs. 758.0 mL/minute, P < 0.001). Moreover, resistance index (RI) of AVF after VAIVT was lower than that before VAIVT (0.61 vs. 0.53, P < 0.01). Although αhANP did not change before and after VAIVT (55.6 vs. 54.9 pg/mL, P = 0.099), BNP after VAIVT was significantly higher than that before VAIVT (145.2 vs. 175.0 pg/mL, P < 0.05). Factors correlated with the increase in BNP were flow volume of AVF before VAIVT (r = -0.458, P = 0.049) and levels of BNP before VAIVT (r = 0.472, P = 0.041). There was no significant correlation between the increase in αhANP with flow volume of AVF before VAIVT, levels of αhANP before VAIVT. Patients with high levels of BNP and low flow volume of AVF before VAIVT were considered to have a high risk of developing heart failure after VAIVT.

Clinical Value of Natriuretic Peptides in Predicting Time to Dialysis in Stage 4 and 5 Chronic Kidney Disease Patients

Background

Anticipating the time to renal replacement therapy (RRT) in chronic kidney disease (CKD) patients is an important but challenging issue. Natriuretic peptides are biomarkers of ventricular dysfunction related to poor outcome in CKD. We comparatively investigated the value of B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) as prognostic markers for the risk of RRT in stage 4 and 5 CKD patients, and in foretelling all-cause mortality and major cardiovascular events within a 5-year follow-up period.

Methods

Baseline plasma BNP (Triage, Biosite) and NT-proBNP (Elecsys, Roche) were measured at inclusion. Forty-three patients were followed-up during 5 years. Kaplan-Meier analysis, with log-rank testing and hazard ratios (HR), were calculated to evaluate survival without RRT, cardiovascular events or mortality. The independent prognostic value of the biomarkers was estimated in separate Cox multivariate analysis, including estimated glomerular filtration rate (eGFR), creatininemia and comorbidities.

Results

During the first 12-month follow-up period, 16 patients started RRT. NT-proBNP concentration was higher in patients who reached endpoint (3221 ng/L vs 777 ng/L, p = 0.02). NT-proBNP concentration > 1345 ng/L proved significant predictive value on survival analysis for cardiovascular events (p = 0.04) and dialysis within 60 months follow-up (p = 0.008). BNP concentration > 140 ng/L was an independent predictor of RRT after 12 months follow-up (p<0.005), and of significant predictive value for initiation of dialysis within 60 months follow-up.

Conclusions

Our results indicate a prognostic value for BNP and NT-proBNP in predicting RRT in stage 4 and 5 CKD patients, regarding both short- and long-term periods. NT-proBNP also proved a value in predicting cardiovascular events. Natriuretic peptides could be useful predictive biomarkers for therapeutic guidance in CKD.

N-terminal pro-B-type natriuretic peptide variability in stable dialysis patients

BACKGROUND AND OBJECTIVES

Monitoring N-terminal pro-B-type natriuretic peptide (NT-proBNP) may be useful for assessing cardiovascular risk in dialysis patients. However, its biologic variation is unknown, hindering the accurate interpretation of serial concentrations. The aims of this prospective cohort study were to estimate the within- and between-person coefficients of variation of NT-proBNP in stable dialysis patients, and derive the critical difference between measurements needed to exclude biologic and analytic variation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Fifty-five prevalent hemodialysis and peritoneal dialysis patients attending two hospitals were assessed weekly for 5 weeks and then monthly for 4 months between October 2010 and April 2012. Assessments were conducted at the same time in the dialysis cycle and entailed NT-proBNP testing, clinical review, electrocardiography, and bioimpedance spectroscopy. Patients were excluded if they became unstable.

RESULTS

This study analyzed 136 weekly and 113 monthly NT-proBNP measurements from 40 and 41 stable patients, respectively. Results showed that 22% had ischemic heart disease; 9% and 87% had left ventricular systolic and diastolic dysfunction, respectively. Respective between- and within-person coefficients of variation were 153% and 27% for weekly measurements, and 148% and 35% for monthly measurements. Within-person variation was unaffected by dialysis modality, hydration status, inflammation, or cardiac comorbidity. NT-proBNP concentrations measured at weekly intervals needed to increase by at least 46% or decrease by 84% to exclude change due to biologic and analytic variation alone with 90% certainty, whereas monthly measurements needed to increase by at least 119% or decrease by 54%.

CONCLUSIONS

The between-person variation of NT-proBNP was large and markedly greater than within-person variation, indicating that NT-proBNP testing might better be applied in the dialysis population using a relative-change strategy. Serial NT-proBNP concentrations need to double or halve to confidently exclude change due to analytic and biologic variation alone.

Heart failure in patients with chronic kidney disease: a systematic integrative review

Introduction. Heart failure (HF) is highly prevalent in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) and is strongly associated with mortality in these patients. However, the treatment of HF in this population is largely unclear. Study Design. We conducted a systematic integrative review of the literature to assess the current evidence of HF treatment in CKD patients, searching electronic databases in April 2014. Synthesis used narrative methods. Setting and Population. We focused on adults with a primary diagnosis of CKD and HF. Selection Criteria for Studies. We included studies of any design, quantitative or qualitative. Interventions. HF treatment was defined as any formal means taken to improve the symptoms of HF and/or the heart structure and function abnormalities. Outcomes. Measures of all kinds were considered of interest. Results. Of 1,439 results returned by database searches, 79 articles met inclusion criteria. A further 23 relevant articles were identified by hand searching. Conclusions. Control of fluid overload, the use of beta-blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and optimization of dialysis appear to be the most important methods to treat HF in CKD and ESRD patients. Aldosterone antagonists and digitalis glycosides may additionally be considered; however, their use is associated with significant risks. The role of anemia correction, control of CKD-mineral and bone disorder, and cardiac resynchronization therapy are also discussed.

The effects of super-flux (high performance) dialyzer on plasma glycosylated pro-B-type natriuretic peptide (proBNP) and glycosylated N-Terminal proBNP in end-stage renal disease patients on dialysis

Background

Plasma BNP levels are predictive of prognosis in hemodialysis patients. However, recent studies showed that the current BNP immunoassay cross-reacts with glycosylated proBNP, and the NT-proBNP assay underestimates glycosylated NT-proBNP. In addition, the recently developed high performance dialyzer removes medium-sized molecular solutes such as β2-microgloburin. We therefore investigated the effects of high performance dialysis on measured levels of glycosylated proBNP, glycosylated NT-proBNP and other BNP-related peptides in end-stage renal disease (ESRD) patients on hemodialysis.

Method

The relationships between clinical parameters and BNP-related molecule were also investigated. We used our newly developed immunoassay to measure plasma total BNP and proBNP in 105 normal subjects and 36 ESRD patients before and after hemodialysis. Plasma NT-proBNP was measured using Elecsys II after treatment with or without deglycosylating enzymes. We also measured plasma ANP and cGMP using radioimmunoassays.

Results

All the measured BNP-related peptides were significantly higher in ESRD patients than healthy subjects. Total BNP (−38.9%), proBNP (−29.7%), glycoNT-proBNP (−45.5%), nonglycoNT-proBNP (−53.4%), ANP (−50.4%) and cGMP (−72.1%) were all significantly reduced after hemodialysis, and the magnitude of the reduction appeared molecular weight- dependent. Both the proBNP/total BNP and glycoNT-proBNP/nonglycoNT-proBNP ratios were increased after hemodialysis. The former correlated positively with hemodialysis vintage and negatively with systolic blood pressure, while the latter correlated positively with parathyroid hormone levels.

Conclusion

These results suggest that hemodialysis using super-flux dialyzer removes BNP-related peptides in a nearly molecular weight-dependent manner. The ProBNP/total BNP and glycoNT-proBNP/nonglycoNT-proBNP ratios appear to be influenced by hemodialysis-related parameters in ESRD patients on hemodialysis.

Role of B-type natriuretic peptide as a marker of mortality in acute kidney injury patients treated with continuous renal replacement therapy

OBJECTIVES

Acute kidney injury (AKI) treated with continuous renal replacement therapy (CRRT) is associated with poor outcome. Plasma B-type natriuretic peptide (BNP) is a biomarker related to fluid volume overload, and is elevated in AKI patients. The purpose of the study was to assess whether BNP levels at the time of starting CRRT could be used as a predictor of mortality in patients with AKI receiving CRRT.

METHODS

We conducted a prospective observational cohort study enrolling 149 patients with AKI receiving CRRT. The primary outcome was mortality during CRRT.

RESULTS

The median BNP level of 84 (56.3%) patients who expired was significantly higher than that of those who survived (1812.5 vs. 475.0 pg/mL; p = 0.01). Receiver operating characteristic curves demonstrated BNP levels as a predictor of mortality during CRRT with an area under the curve of 0.77 (p = 0.000), and the optimal threshold for BNP was 1054 pg/mL. Patients with BNP levels above 1054 pg/mL had a significantly higher mortality (76.6 vs. 34.7%; p = 0.01).

CONCLUSION

Elevated BNP level is associated with mortality in patients with AKI receiving CRRT.

B-type natriuretic peptide is not a volume marker among patients on hemodialysis

BACKGROUND

Although the cardiac biomarker B-type natriuretic peptide (BNP) is strongly related to mortality in end-stage renal disease (ESRD), whether it is a predictor of weight change or blood pressure (BP) response upon probing dry weight among hypertensive hemodialysis patients remains unknown. The purpose of this study was to examine among people with hypertension on hemodialysis whether BNP is a biomarker of excess volume.

METHODS

Hypertensive hemodialysis patients (n = 150) were randomized to a control group (n = 50) or an ultrafiltration group (n = 100) and followed up for 30 dialysis treatments. After a baseline run-in of six treatments, those assigned to the ultrafiltration group had dry weight probed over 8 weeks. Forty-four-hour interdialytic ambulatory BP and predialysis BNP were measured at the end of run-in period, at 4 weeks and at 8 weeks.

RESULTS

The median BNP concentration was 93 pg/mL (interquartile range 31-257 pg/mL). The magnitude of decline in the BNP depended on the baseline concentration of BNP, but did not require probing dry weight or weight loss. No relationship existed between decline in postdialysis weight upon probing dry weight and baseline BNP. Furthermore, reduction in the BNP was not required for decline in postdialysis weight. Predialysis log BNP modestly predicted ambulatory systolic and pulse pressure independently of other risk factors. No relationship was found between decline in BP upon probing dry weight and baseline BNP. Upon probing dry weight, reduction in BNP was not required for decline in systolic ambulatory BP.

CONCLUSION

Taken together, these data suggest that among hypertensive patients on hemodialysis BNP is not a volume marker.

Possible correlation among echocardiographic measures, serum brain natriuretic peptide, and angiotensin II levels in hypertensive kidney transplanted children

OBJECTIVES

Ambulatory blood pressure monitoring is the standard for determining patients at risk of hypertension. Left ventricular hypertrophy is common in kidney transplant recipients. We evaluated the correlation between blood pressure measures achieved by ambulatory blood pressure monitoring and conventional (office) methods.

MATERIALS AND METHODS

This cross-sectional study was done from December 2009 to October 2010 at Alzahra Hospital in Isfahan, Iran. Sixty five participants, 35 kidney transplant recipients under 20 years old, and 30 control subjects of the same age were recruited. Five kidney recipients did not complete the study and were excluded. Blood pressure was measured by ambulatory blood pressure monitoring and conventional methods. Echocardiographic study was done for kidney transplant recipients. Serum brain natriuretic peptide and angiotensin II levels were determined in case and control groups.

RESULTS

Office-recorded systolic and/or diastolic hypertension was observed in 43.4% and 55.3% of patients. According to ambulatory blood pressure monitoring, 86% of kidney transplant recipients had systolic BP load. Left ventricular hypertrophy (defined according to the left ventricular mass index [left ventricular mass index/height]) was seen in 53.3% of the patients. The existence of left ventricular hypertrophy revealed a positive correlation with ambulatory blood pressure monitoring systolic and diastolic night blood pressure and systolic nondipper. Left ventricular mass index showed a positive correlation with brain natriuretic peptide level. Furthermore, the existence of left ventricular hypertrophy was positively correlated with angiotensin II level.

CONCLUSIONS

Only ambulatory blood pressure monitoring systolic and diastolic blood pressures (nondippers) were positively correlated with left ventricular hypertrophy and higher left ventricular mass index. Serum levels of brain natriuretic peptide and angiotensin II had a positive relation with left ventricular hypertrophy. Measuring brain natriuretic peptide and angiotensin II in the clinical setting screens patients at risk of left ventricular hypertrophy.

Effects of residual renal function on left ventricle and analysis of related factors in patients with hemodialysis

BACKGROUND

Left ventricular hypertrophy (LVH) and systolic dysfunction would predict the mortality of patients undergoing maintenance hemodialysis. The cause of LVH is usually related to the increase of total peripheral vascular resistance and overloading volume. The presence of residual diuresis enables greater control of the volume. This study evaluated the effects of residual renal function (RRF) on the left ventricle and analyzed the related factors involved in hemodialysis patients.

METHODS

A total of 59 hemodialysis patients were classified into two groups. The patients in the RRF (RRF+) group had a urine volume greater than 200 mL/24 h, and the patients in the non-RRF (RRF-) group had a urine volume less than 200 mL/24 h. B-type natriuretic peptide (BNP), blood total homocysteine (tHcy), and blood biochemical indexes were determined for the patients in both groups. Echocardiography and Doppler tests were performed to determine the cardiac indexes.

RESULTS

LVH and systolic dysfunction in the RRF+ group were less severe than those in the RRF- group. The concentration of tHcy and BNP in patients with RRF was decreased in comparison with those without RRF. The concentration of tHcy and BNP was positively correlated with the residual diuresis.

CONCLUSIONS

There were distinct ventricular geometric patterns and different functional performances between RRF+ and RRF- groups. The presence of residual diuresis had a beneficial effect on the left ventricular function in hemodialysis patients.

Biomarkers in hemodialysis patients

Patients with chronic kidney disease (CKD) are, compared to the general population, at higher risk of cardiovascular disease (CVD), including sudden death, coronary artery disease (CAD), congestive heart failure (HF), stroke, and peripheral artery disease. The presence of CVD is independently associated with kidney function decline. Renal insufficiency is a strong and independent predictor of mortality in patients with different CKD stages. The interplay of traditional and nontraditional risk factors is complex such that risk factor profiles are different in CKD patients. Seemingly, paradoxical associations between traditional risk factors and cardiovascular outcome complicate efforts to identify real cardiovascular etiology in these patients. Additional tools are often required to aid clinical assessment of cardiovascular risk. Recently, a number of cardiovascular biomarkers were identified as predictors of outcome in CVD. These may be used to guide early diagnosis and therapy for CVD or may predict outcome in CKD. This review focuses on the potential diagnostic and prognostic use of some important new biomarkers including brain natriuretic peptide (BNP), cardiac troponins (cTns), inflammatory markers, adhesion molecules, and asymmetric dimethylarginine (ADMA) in CKD as well as those patients with end-stage renal failure.

Plasma BNP, a useful marker of fluid overload in hospitalized hemodialysis patients

Hospitalization for intercurrent illness frequently disrupts the nutritional status of hemodialysis (HD) patients and jeopardizes the dry weight prescription. We report in this study the evolution of brain natriuretic peptide (BNP), blood pressure and body weight in hospitalized patients and the relationship between BNP plasma level and nutritional and inflammation parameters. We have studied 42 patients requiring hospitalization (F/M: 18/24; 72.5 ± 12.5 years old; 19/42 with diabetes). The plasma BNP levels at baseline, during hospitalization (BNP-Hosp), and in the recovery phase were compared. Predialysis and postdialysis blood pressure and postdialysis body weight were recorded and compared. BNP-Hosp increased significantly when compared with BNP levels at baseline, from 421 ± 647.2 pg/mL to 1584 ± 1584.4 pg/mL (P < 0.0001). Brain natriuretic peptide decreased from 1223 ± 1342.1 pg/mL during hospitalization to 616 ± 892.1 pg/mL after discharge (P = 0.005). The BNP-Hosp was positively correlated with C-reactive protein (P = 0.003) and negatively correlated with serum prealbumin (P = 0.0001) and albumin (P = 0.0001). The postdialysis body weight prescription decreased from 71.0 ± 15.7 kg at baseline to 70.5 ± 15.4 kg during hospitalization and to 67.8 ± 14.4 kg 4 months after discharge (P = 0.0032). Our study displays clearly the significant changes of plasma BNP levels occurring during intercurrent events. Fluid overload triggered by inflammation-associated catabolism and the lag time for dry weight adjustment is the cause of this finding. Hence, plasma BNP level may be used as a marker of fluid overload in patients with intercurrent events and may allow efficient dry weight adjustment. We cannot rule out an effect of inflammation on BNP synthesis.

[Cardiac markers in different degrees of chronic kidney disease: influence of inflammation and previous heart disease]

BACKGROUND AND OBJECTIVE

Troponin T (TnT), brain natriuretic peptide (BNP) and its precursor (NT-proBNP) are useful markers of acute coronary events and heart failure. The aim of this study was to analyze the influence of chronic renal failure, inflammation and heart disease in these biomarkers.

PATIENTS AND METHODS

In 266 patients with different stages of chronic renal diseases, the following parameters were measured: cardiac markers (TnT, BNP and NT-proBNP), renal function, inflammatory markers (hsCRP, fibrinogen, albumin, uric acid and white blood cells). We recorded the cardiovascular history. Ventricular dysfunction and left ventricular hypertrophy were assessed by echocardiography.

RESULTS

A significant correlation between cardiac markers and inflammatory parameters such as fibrinogen, hsCRP and albumin was found. Age (OR 1.05, P = .021), serum albumin (OR: 0.06, P=.006), ischemic heart disease (OR: 8.17, P=.0092) and renal failure (OR: 1.67, P=.05) were predictors of higher BNP levels. Age (OR 1.05, P=.0097), serum albumin (OR: 0.12, P=.001), ischemic heart disease (OR: 3.43, P=.034), renal failure (OR: 1, 65, P=.036) and heart failure (OR: 4.33, P=.0312) were predictors of elevated NT-proBNP. Previous ischemic heart disease alone increased TnT levels (OR: 6.51, P=.0012).

CONCLUSIONS

Age, previous cardiac disease and inflammation increase cardiac marker levels in patients with different stages of renal disease, but the degree of renal failure is an important factor influencing NT-proBNP levels. However, ischemic heart disease alone increases the levels of TnT.

Change in cardiovascular disease status in peritoneal dialysis patients: a 5-year single-center experience

BACKGROUND

We compared patient characteristics, atherosclerosis, left ventricular hypertrophy, and dialysis practice patterns of peritoneal dialysis (PD) patients with change in cardiovascular disease (CVD) status and no change in CVD status in Chinese PD center.

METHODS

This study included all patients who started on PD between 1 January 2003 and 30 June 2009 at the Renji Hospital, Shanghai Jiaotong University School of Medicine, China. They were followed up from the date of PD initiation until new-onset CVD.

RESULTS

The median follow-up time was 44.13 months. In patients with preexisting CVD, both high triglyceride (1.43 ± 0.89 mmol/L vs. 2.64 ± 1.58 mmol/L, p < 0.001) and the duration of dialysis (45.76 ± 13.28 months vs. 58.68 ± 13.74 months, p < 0.01) were independent predictors of CVD progression and the left atrial dimension, left ventricle septal thickness, left ventricle mass index (LVMI), and intima-media thickness (IMT) also had the difference. On the other hand, in patients without preexisting CVD, the dialysis adequacy and nutritional status are important during the follow-up. Serum albumin in CVD group was lower than in no CVD group (30.86 ± 4.77 g/L vs. 36.04 ± 6.40 g/L, p < 0.05). Creatinine clearance (CCr) and Kt/V in CVD group were lower than in no CVD group (CCr 57.24 ± 13.86 L/week vs. 71.06 ± 23.96 L/week, p < 0.05; Kt/V 1.82 ± 0.41 vs. 2.23 ± 0.57, p < 0.05).

CONCLUSION

In patients with preexisting CVD, it is important to address traditional risk factors such as LVMI, IMT, and lipid profile. In patients without preexisting CVD, we should pay more attention to the nutritional status and PD prescription in order to lower the morbidity of CVD in these PD patients.

Clinical usefulness of novel prognostic biomarkers in patients on hemodialysis

Prognosis, risk stratification and monitoring the effects of treatment are fundamental elements in the decision-making process when implementing prevention strategies for chronic kidney disease. The use of biomarkers is increasingly proposed as a method to refine risk stratification and guide therapy. In this Review, we present basic concepts regarding the validation of biomarkers and highlight difficulties inherent to the identification of useful new biomarkers in patients on hemodialysis. We focus on prognostic biomarkers that have been consistently linked to survival in this group of patients. To date, no biomarker has had sufficient full-scale testing to qualify as a useful addition to standard prognostic factors or to guide the prescription of specific treatments in this population. Furthermore, little information exists on the relative strength of various biomarkers for their prediction of mortality. A multimarker approach might refine prognosis in patients on hemodialysis, but this concept needs to be properly evaluated in large longitudinal studies and clinical trials. The potential of proteomics for the identification and study of new biomarkers in the pathophysiology of cardiovascular disease in patients with end-stage renal disease is also discussed.

Brain natriuretic peptide between traditional and nontraditional risk factors in hemodialysis patients: analysis of cardiovascular mortality in a two-year follow-up

BACKGROUND

The ability of brain natriuretic peptide (BNP) together with other traditional and nontraditional risk factors to predict cardiovascular (CV) mortality in hemodialysis (HD) patients has not been well established. The aim of this prospective study was to determine the predictive cutoff values of baseline measurement of BNP along with the known CV disease risk factors to predict all-cause and CV mortality in HD patients.

METHODS

BNP concentration before HD was measured in 125 prevalent HD patients (age 53.0 ± 13.5 years, HD vintage 75.2 ± 61.0 months). In addition, several traditional CV risk factors (blood pressure, dyslipidemia, diabetes mellitus, body mass index, left ventricular hypertrophy) and uremia/dialysis-related CV risk factors (anemia, calcium and phosphate impairment, malnutrition, inflammation, ultrafiltration, HD duration, Kt/V) were examined.

RESULTS

During the 2-year follow-up, we lost 28 out of 125 patients (22.5%), with CV disease (65.7%) being the main cause of mortality. The cutoff point for BNP, as predictor of the clinical outcome, according to the ROC curve was 1,194 pg/ml for CV mortality with sensitivity and specificity of 63 and 65%, respectively (AUC 0.61 and confidence interval (CI) 95% 0.47-0.75). Kaplan-Meier analysis showed that all-cause (log-rank, p = 0.002) and CV mortality (log-rank, p = 0.001) were the cause of a significantly lower survival in patients with a mean BNP >1,200 pg/ml. The univariate Cox regression analysis found the following factors to be predictors of all-cause mortality: hemoglobin (<110 g/l), phosphorus (>1.78 mmol/l), albumin (<40 g/l), C-reactive protein (CRP ≥ 10 mg/l), BNP (>1,200 pg/ml) and cardiac ejection fraction (≤ 55%). The multivariate Cox regression analyses demonstrated that only CRP ≥ 10 mg/l with a hazard ratio (HR) 6.82 (CI 95% 1.86-24.9, p = 0.004) and BNP >1,200 pg/ml with HR 5.79 (CI 95% 1.58-21.3, p = 0.004) were predictors of all-cause mortality. BNP >1,200 pg/ml with HR 13.52 (CI 95% 1.68-108.9, p = 0.014) was found to be an even stronger predictor of CV mortality than CRP ≥ 10 mg/l with HR 6.53 (CI 95% 1.35-31.6, p = 0.020).

CONCLUSIONS

Our study pointed out that BNP >1,200 pg/ml as a marker of cardiac dysfunction and CRP ≥ 10 mg/l as a marker of inflammation identify HD patients at increased risk of CV mortality.

[Heart failure in haemodialysis patients: evaluation and treatment]

Cardiovascular diseases are the leading cause of death in patients on haemodialysis. Cardiovascular mortality rate in these patients is approximately 9% per year, with the highest prevalence of left ventricular hypertrophy, ischemic heart disease and congestive heart failure being the most frequent cardiovascular complications. Risk factors for cardiac failure include hypertension, disturbed lipid metabolism, oxidative stress, microinflammation, hypoalbuminemia, anaemia, hyperhomocysteinemia, and increased concentration of asymmetric dimethylarginine, increased shunt blood flow and secondary hyperparathyroidism. Diagnostic strategy for early detection of patients with increased risk for the development of asymptomatic disturbances of systolic and diastolic left ventricular function should include echocardiografic examination, tests for determining coronary vascular disease, as well as tests of myocardial function (BNP, Nt-proBNP). Early detection of patients with a high risk of congestive heart failure enables timely implementation of adequate therapeutic strategy to provide high survival rate of HD patients.

Comparison of B-type natriuretic peptide and NT proBNP as predictors of survival in patients on high-flux hemodialysis and hemodiafiltration

End stage renal failure is associated with very high risk of cardiovascular disease. Serum levels of B-type natriuretic peptide (BNP) and NT proBNP reflect cardiovascular risk but it is unknown which of these peptides is a better predictor of survival in this population. BNP and NT proBNP levels and other relevant parameters were measured in 103 patients on high-flux hemodialysis (HD) and hemodiafiltration. Patients were followed for 4 years or until transplantation or death. Median BNP level was 262 pg/mL while the corresponding NT proBNP level was 362 pg/mL. Levels of these peptides were significantly lower in patients receiving hemodiafiltration than in those on high-flux HD. Only 1 of the 26 patients with normal NT proBNP died during follow-up while 3 of the 33 patients with normal BNP levels died in the same period. Both median BNP and NT proBNP levels were higher in those who died during follow-up than in those who survived 4 years. Cox Proportional Hazard models showed that both logBNP and log NT proBNP were independent predictors of survival. The area under the receiver operating characteristic curve was very similar for BNP and NT proBNP (0.779 vs. 0.781) for predicting 4-year survival. Net reclassification improvement analysis showed that adding NT proBNP to the baseline model lead to improved prediction of 4-year survival. BNP and NT proBNP levels were markedly elevated in HD patients and were highly predictive of survival. NT proBNP may have marginal advantage over BNP in predicting survival in this population.

Elevation of B-type natriuretic peptide is a sensitive marker of left ventricular diastolic dysfunction in patients with maintenance haemodialysis

OBJECTIVE

To determine the clinical value of B-type natriuretic peptide (BNP) in diagnosing left ventricular diastolic dysfunction (LVDD) associated with maintenance haemodialysis (MHD) population.

METHODS

Plasma BNP was determined in 59 MHD patients with normal ejection fraction. The ratio of early to late annular velocity (E'/A') was determined by tissue Doppler imaging as a parameter of diastolic function.

RESULTS

LVDD occurred in 66% of the patients. Receiver-operating characteristic curve analyses identified a cut-off of 353.6 pg ml(-1) as the one with the highest sensitivity and specificity for detecting LVDD.

CONCLUSIONS

Plasma BNP may serve as a potential biomarker in diagnosing LVDD in MHD patients with normal systolic function.

Current perspectives on diagnosis of heart failure in long-term dialysis patients

Cardiovascular disease is highly prevalent in patients with chronic kidney failure treated using dialysis. The risk of cardiovascular events is estimated to be at least 2- to 10-fold higher in dialysis patients than in age-, race-, and sex-matched persons with normal kidney function. A significant proportion of cardiovascular events in long-term dialysis patients is caused by heart failure, and the presence of heart failure is predictive of a poor prognosis. Despite the significant morbidity and mortality associated with heart failure, very few therapeutic options are proved to prevent and treat the progression of this complication in dialysis patients. There are several potential reasons for this, chiefly reflecting both challenges with diagnosis due to the coexistence of volume overload and a paucity of adequately powered prospective randomized controlled trials that examine the efficacy of different therapeutic options in dialysis patients with cardiac disease or heart failure. Thus, unlike in the general population, very few advances have been made in managing this severe complication in dialysis patients. In this article, an overview of the prevalence, severity, and risk factors for heart failure in maintenance dialysis patients is provided and the diagnosis of heart failure in these patients is revisited.

How does volume status affect BNP and troponin levels as markers of cardiovascular status in peritoneal dialysis?

Cardiac biomarkers such as brain natriuretic peptide, amino-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac troponin provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic hemodialysis patients, both biomarkers-NT-proBNP and troponin-are elevated despite the absence of cardiac ischemia. The elevation of cardiac biomarkers in chronic hemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. Furthermore, they can serve as tools for volume assessment for optimization of the fluid management aspect of dialysis. However, the association of both these markers in peritoneal dialysis is not clear. Therefore, the authors reviewed the literature to examine the role of these markers in peritoneal dialysis patients both as prognostic indicators as well as tools for volume assessment.

Serum levels of N-terminal pro-B-type natriuretic peptide are associated with allograft function in recipients of renal transplants

BACKGROUND

B-type natriuretic peptide (BNP) plays a key role in the regulation of volume homeostasis, and elevated blood levels of BNP are associated with end-stage renal disease. Renal transplantation leads to a decrease of elevated BNP levels with established graft function. Assessment of N-terminal pro-BNP (NT-proBNP) is established as reflecting volume homeostasis, and we therefore studied the relationship between NT-proBNP and allograft function in a prospective study.

METHODS

NT-proBNP was assessed in 76 patients with end-stage renal disease undergoing renal transplantation. Patients were grouped according to immediate or delayed graft function. The degree of allograft function was assessed from the estimated glomerular filtration rate according to the MDRD formula.

RESULTS

In patients with immediate graft function (n = 48), median NT-proBNP decreased immediately after transplantation; in patients with delayed function (n = 28), median NT-proBNP first increased and then decreased as function improved. Patients with early acute rejection showed significantly higher NT-proBNP levels prior to transplantation than patients without rejection. NT-proBNP levels measured 2 or 3 weeks post-transplant were significantly correlated with the estimated glomerular filtration rate 1 year after transplantation.

CONCLUSIONS

An association was observed between renal allograft function and post-transplant levels of NT-proBNP. The association was not found to be a useful general predictor for graft function in individual patients in a clinical setting, as the range of NT-proBNP levels measured was too wide.