Diagnostic potential of circulating natriuretic peptides in chronic kidney disease

Brain natriuretic peptide and N-terminal pro b-type natriuretic peptide in kidney transplantation: More than just cardiac markers

Although kidney transplantation (KT) is the best treatment option for most patients with end-stage kidney disease (ESKD) due to reduced mortality, morbidity and increased quality of life, long- term complications such as chronic kidney allograft dysfunction (CKAD) and increased cardiovascular disease burden are still major challenges. Thus, routine screening of KT recipients (KTRs) is very important to identify and quantify risks and guide preventative measures. However, no screening parameter has perfect sensitivity and specificity, and there is unmet need for new markers. In this review, we evaluate brain natriuretic peptide (BNP) and N-terminal pro b-type natriuretic peptide (NT-proBNP) as promising markers for risk stratification in the kidney transplant recipients (KTRs). The usefulness of these markers are already proven in heart failure, hypertension, coronary artery disease. In the context of KT, evidence is emerging. BNP and NT-proBNP has shown to be associated with kidney function, graft failure, echocardiographic parameters, major cardiovascular events and mortality but the underlying mechanisms are not known. Although BNP and NT-proBNP interact with immune system, renin angiotensin system and sympathetic system; it is not known whether these interactions are responsible for the clinical findings observed in KTRs. Future studies are needed whether these biomarkers show clinical efficacy, especially with regard to hard outcomes such as major adverse cardiovascular events and graft dysfunction and whether routine implementation of these markers are cost effective in KTRs.

Circulating osteoprotegerin as a cardiac biomarker for left ventricular diastolic dysfunction in patients with pre-dialysis chronic kidney disease: the KNOW-CKD study

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a major cause of mortality in patients with chronic kidney disease (CKD), and diagnosis is challenging. Moreover, no specific biomarker for HFpEF has been validated in patients with CKD. The present study aimed to investigate the association between serum osteoprotegerin (OPG) levels and the risk of left ventricular diastolic dysfunction (LVDD), a surrogate of HFpEF, in patients with pre-dialysis CKD.

METHODS

A total of 2039 patients with CKD at stage 1 to pre-dialysis 5 were categorized into quartiles (Q1 to Q4) by serum OPG levels, and were cross-sectionally analyzed. The study outcome was LVDD, which was operationally defined as the ratio of early transmitral blood flow velocity to early diastolic velocity of the mitral annulus (E/e') > 14.

RESULTS

In the analysis of baseline characteristics, higher serum OPG levels were clearly related to the risk factors of HFpEF. A scatter plot analysis revealed a moderate correlation between serum OPG levels and E/e' (R = 0.351, P < 0.001). Logistic regression analysis demonstrated that the risk of LVDD in Q3 (adjusted odds ratio 2.576, 95% confidence interval 1.279 to 5.188) and Q4 (adjusted odds ratio 3.536, 95% confidence interval 1.657 to 7.544) was significantly higher than that in Q1.

CONCLUSIONS

Elevated serum OPG levels are associated with the risk of LVDD in patients with pre-dialysis CKD. The measurement of serum OPG levels may help the diagnosis of LVDD, which is an important echocardiographic feature of HFpEF.

Left ventricular dysfunction with preserved ejection fraction: the most common left ventricular disorder in chronic kidney disease patients

Chronic kidney disease (CKD) is a risk factor for premature cardiovascular disease. As kidney function declines, the presence of left ventricular abnormalities increases such that by the time kidney replacement therapy is required with dialysis or kidney transplantation, more than two-thirds of patients have left ventricular hypertrophy. Historically, much research in nephrology has focussed on the structural and functional aspects of cardiac disease in CKD, particularly using echocardiography to describe these abnormalities. There is a need to translate knowledge around these imaging findings to clinical outcomes such as unplanned hospital admission with heart failure and premature cardiovascular death. Left ventricular hypertrophy and cardiac fibrosis, which are common in CKD, predispose to the clinical syndrome of heart failure with preserved left ventricular ejection fraction (HFpEF). There is a bidirectional relationship between CKD and HFpEF, whereby CKD is a risk factor for HFpEF and CKD impacts outcomes for patients with HFpEF. There have been major improvements in outcomes for patients with heart failure and reduced left ventricular ejection fraction as a result of several large randomized controlled trials. Finding therapy for HFpEF has been more elusive, although recent data suggest that sodium-glucose cotransporter 2 inhibition offers a novel evidence-based class of therapy that improves outcomes in HFpEF. These observations have emerged as this class of drugs has also become the standard of care for many patients with proteinuric CKD, suggesting that there is now hope for addressing the combination of HFpEF and CKD in parallel. In this review we summarize the epidemiology, pathophysiology, diagnostic strategies and treatment of HFpEF with a focus on patients with CKD.

Assessment of volemia status using ultrasound examination of the inferior vena cava and spectroscopic bioimpendance in hemodialysis patients

Background/Aim. Hypervolemia is an important risk factor for the development of cardiovascular morbidity and mortality in patients treated with regular hemodialysis. There is still no reliable method for assessing the status of volemia in these patients. The aim of the study was to assess the status of volemia in patients treated with regular hemodialysis by measuring the parameters of the inferior vena cava (IVC) and bioimpedance. Methods. The effect of hemodialysis treatment on ultrasound parameters of the IVC, as well as on the parameters measured by bioimpedance, was examined before and after hemodialysis. The values of the N-terminal prohormone of brain natriuretic peptide (NT-proBNP) were measured both before and after hemodialysis. Forty-five patients were involved in this non-interventional cross-section study, including the patients treated with standard bicarbonate dialysis. According to the interdialytic yield, the patients were divided into three groups: I (up to 2,000 mL), II (2,000?3,000 mL), and III (over 3,000 mL). Results. The values of the IVC parameters and the parameters measured with bioimpedance were significantly lower after treatment with hemodialysis (p < 0.005). The third group of patients had a significantly higher total fluid volume in the body com-pared to the group I, as well as a significantly greater volume of extracellular fluid (p < 0.005). The significantly lower values of NT-proBNP in all groups (p < 0.005) were detected after hemodialysis. After treatment with hemodialysis, a positive correlation was observed between the concentration of NT-proBNP in the serum and the extracellular/intracellular water ratio. However, the correlation between NT-proBNP concentration and total fluid measured by bioimpedance spectroscopy did not reach statistical significance. Conclusion. Measurement of the IVC ultrasound parameters and volemia parameters using bioimpedance significantly contributes to the assessment of the status of volemia. Nevertheless, it cannot be used as a separate parameter, only in combination with all other methods.

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.

Selected cardiovascular risk factors in early stages of chronic kidney disease

Cardiovascular diseases, including hypertension, congestive heart failure, myocardial infarction, stroke and atherosclerosis, are common in patients with chronic kidney disease. Aside from the standard biomarkers, measured to determine cardiovascular risk, new ones have emerged: markers of oxidative stress, apoptosis, inflammation, vascular endothelium dysfunction, atherosclerosis, organ calcification and fibrosis. Unfortunately, their utility for routine clinical application remains to be elucidated. A causal relationship between new markers and cardiovascular diseases in patients with chronic kidney disease remains to be established. First of all, there is a lack of large, randomized trials. Moreover, most studies focus on patients with end-stage renal disease as well as on dialysed patients. In such patients, cardiovascular diseases are already present and advanced while early detection of cardiovascular disease risk factor in patients with early-stages of chronic kidney disease would allow more precise prognosis and, as a result, changes in treatment algorithm. In this article, we conduct a comprehensive review of literature for publications relating to cardiovascular risk factors in patients with early-stages of chronic kidney disease. Overall, there are many encouraging advances in detection of cardiovascular risk factors that are making the future more promising for patients suffering from chronic kidney disease.

NT-ProBNP Predicts Total Mortality, Emergency Department Visits, Hospitalization, Intensive-Care Unit Admission, and Cardiovascular Events in Hemodialysis Patients

N-terminal pro b-type natriuretic peptide (NT-proBNP) was considered a prognostic factor for mortality in hemodialysis patients in previous studies. However, NT-proBNP has not been fully explored in terms of predicting other clinical outcomes in hemodialysis patients. This study aimed to investigate if NT-proBNP could predict emergency department (ED) visits, hospitalization, admission to intensive-care unit (ICU), and cardiovascular incidents in hemodialysis patients. Serum NT-proBNP and other indicators were collected in 232 hemodialysis patients. Patients were followed up for three years or until mortality. Outcomes included mortality, number of ED visits, hospitalizations, admissions to ICU, and cardiovascular events. NT-proBNP was found to predict recurrent ER visits, hospitalization, admission to ICU, cardiovascular events, and mortality, after adjusting for covariates. Time-dependent area under the curve (AUC) was used to evaluate the NT-proBNP predicting ability. Using time-dependent AUC, NT-proBNP has good predictive ability for mortality, ED visit, hospitalization, ICU admission, and cardiovascular events with the best predictive ability occurring at approximately 1 year, and 5th, 62nd, 63rd, and 63rd days respectively. AUC values for predicting mortality, hospitalization, and ICU admission decreased significantly after one year. NT-proBNP can be applied in predicting ED visits but is only suitable for the short-term. NT-proBNP may be used for predicting mortality in the long term.

Validation of echocardiographic criteria for the clinical diagnosis of heart failure in chronic kidney disease

Background

The Acute Dialysis Quality Initiative (ADQI) XI Workgroup has suggested defining heart failure (HF) in patients with end-stage renal disease by the presence of at least one out of eight predefined echocardiographic criteria. Given the high prevalence of echocardiographic alterations in chronic kidney disease (CKD) patients, we hypothesized that application of echocardiographic ADQI criteria will result in overdiagnosis of HF, without providing substantial prognostic information.

Methods

Among 472 CKD stage G2-G4 patients recruited in the CARE FOR HOMe study, we assessed the presence of left-ventricular (LV) hypertrophy, valvular dysfunction, high left-atrial volume index (LAVI), systolic and diastolic LV dysfunction, enlarged LV diameter, and altered regional LV wall contractility. According to the ADQI proposal, presence of one or more of these alterations defined HF. We followed all patients for the occurrence of cardiac decompensation, defined as hospital admission for decompensated HF.

Results

A total of 313 (66%) out of 472 patients fulfilled at least one ADQI echocardiographic criterion for HF. Echocardiographic alterations were more common in advanced (G3b/G4: 80%) than in milder (G2/G3a: 56%) CKD. Within subcategories of echocardiographic criteria, an increased LAVI (50%) and diastolic dysfunction (30%) were the most frequent findings. During follow-up of 4.3 ± 2.0 years, the majority (87%) of all 313 patients who fulfilled ADQI echocardiographic criteria were not hospitalized for cardiac decompensation.

Conclusions

Echocardiographic criteria proposed by ADQI as a precondition for the clinical staging of HF are virtually omnipresent among CKD patients. By labelling a majority of CKD patients as having HF, application of ADQI criteria fails to specifically identify patients at high risk for future cardiac events.

Effects of lowered dialysate sodium on left ventricle function and brain natriuretic peptide in maintenance of hemodialysis patients

Introduction:

Impaired diastolic flow is characterized by decreased left ventricular (LV) filling diastole, abnormal LV distensibility, or delayed relaxation. B-Type natriuretic peptide (BNP) is an indicator of various cardiovascular diseases and body volume status. The aim of this study was to determine whether the lowering of dialysate sodium (Na) levels is effective on LV systolic and diastolic parameters and BNP in the maintenance of hemodialysis patients.

Materials and Methods:

The study included 49 chronic hemodialysis patients. Left atrium (LA) diameter and LV ejection fraction, LV systolic and diastolic diameter, deceleration time (DT), pulmonary artery pressure (PAP), inferior vena cava diameter (IVCD), early diastolic transmitral flow ( E) and late diastolic transmitral flow ( A) velocities, E/ A ratio, isovolumic relaxation time, peak early diastolic velocity ( E′), late diastolic velocity ( A′) of tissue Doppler mitral annulus, and flow propagation velocity of mitral inflow ( Vp) were measured before and 6 months after hemodialysis with low Na dialysate.

Results:

Six months after low Na hemodialysis, a decrease was observed in echocardiographic parameters such as PAP and IVCD ( p < 0.05, p < 0.001, and p < 0.001, respectively). However, a significant difference was not observed in LA diameter. In LV diastolic measurement of E and A waves, E/ A ratio, DT, Vp, septal E′ and A′, and lateral E′ and A′ exhibited significant improvement by low Na HD. BNP level was significantly reduced ( p < 0.001).

Conclusions:

Lowered dialysate Na concentration improves PAP, IVCD, and LV diastolic properties assessed by mitral inflow filling, tissue Doppler velocity, and mitral inflow velocity propagation.

Are levels of NT-proBNP and SDMA useful to determine diastolic dysfunction in chronic kidney disease and renal transplant patients?

BACKGROUND

The aim of the study was to determine the clinical usefulness of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and symmetric dimethylarginine (SDMA) for detection of renal and left ventricular (LV) diastolic dysfunction in chronic kidney disease (CKD) patients and renal transplant (RT) recipients.

METHODS

We included 98 CKD and 44 RT patients. We assessed LV function using pulsed-wave Doppler ultrasound. Diastolic dysfunction was defined when the E:A ratio was <1.

RESULTS

Independent predictors of NT-proBNP levels were age, creatinine, and albumin in CKD patients and age and urea in RT patients. Determinants of SDMA in CKD patients were glomerular filtration rate (GFR) and NT-proBNP and creatinine in RT patients. In RT patients with diastolic dysfunction, NT-proBNP and SDMA were significantly higher than in patients without diastolic dysfunction (F = 7.478, P < 0.011; F = 2.631, P < 0.017). After adjustment for GFR, the differences were not seen. In CKD patients adjusted NT-proBNP and SDMA values for GFR were not significantly higher in patients with diastolic dysfunction than in patients without diastolic dysfunction.

CONCLUSIONS

NT-proBNP is useful for detection of LV diastolic dysfunction in RT recipients. When evaluating both NT-proBNP and SDMA it is necessary to consider GFR as a confounding factor.

The peptidic middle molecules: is molecular weight doing the trick?

Chronic kidney disease (CKD) is characterized by a gradual endogenous intoxication caused by the progressive accumulation of bioactive compounds that in normal conditions would be excreted and/or metabolized by the kidney. Uremic toxicity now is understood as one of the potential causes for the excess of cardiovascular disease and mortality observed in CKD. An important family of uremic toxins is that of the peptidic middle molecules, with a molecular weight ranging between 500 and 60,000 Da, which makes them, as a consequence, difficult to remove in the process of dialysis unless the dialyzer pore size is large enough. This review provides an overview of the main and best-characterized peptidic middle molecules and their role as potential culprits of the cardiometabolic complications inherent to CKD patients.

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.

Effect of thermal therapy using hot water bottles on brain natriuretic Peptide in chronic hemodialysis patients

INTRODUCTION

The use of repeated thermal therapy for improving the symptoms of chronic heart failure (CHF) has been recently demonstrated. Usually, thermal therapy requires an infrared dry sauna. However, it is difficult for small clinics to acquire such an expensive and extensive system. The present study assessed the efficacy of its substitution with hot water bottles. Moreover, there are no prior studies demonstrating the efficacy of thermal therapy in hemodialysis patients with CHF.

METHODS

Plasma brain natriuretic peptide (BNP) levels were evaluated in 98 hemodialysis patients in a clinic. Nine patients whose BNP levels were >500 pg/mL agreed to be enrolled in the study and received thermal therapy using hot water bottles.

RESULTS

Plasma BNP levels, a potential marker for CHF, tended to decrease (891 ± 448 to 680 ± 339 pg/mL), but the difference was not significant (P = 0.0845). The oral temperature changed from 36.44 ± 0.45°C to 37.04 ± 0.48°C (+0.597°C, P < 0.0001). No side effects were experienced during the therapy. Moreover, most patients had an improvement in their symptoms and the ability to perform activities of daily living.

CONCLUSION

Thermal therapy using hot water bottles is very safe and tends to reduce plasma BNP levels in hemodialysis patients with CHF.

Circulating natriuretic peptide concentrations in hyperthyroid cats

OBJECTIVES

To assess the influence of thyroid function on natriuretic peptide concentration in hyperthyroid cats before and after treatment.

METHODS

Serum natriuretic peptide concentration was measured in 61 hyperthyroid cats recruited from first-opinion clinics before and after treatment.

RESULTS

Following successful treatment, total thyroxine, heart rate, systolic blood pressure and packed cell volume all decreased and bodyweight and creatinine concentrations increased. Furthermore, a significant (P < 0·001) decline in NT-proBNP concentration but not NT-proANP was identified.

CLINICAL SIGNIFICANCE

Thyroid function has a modest but significant effect on NT-proBNP concentration. Thyroid status should be taken into account when interpreting NT-proBNP concentrations in cats.

Brain natriuretic peptide is related to carotid plaques and predicts atherosclerosis in pre-dialysis patients with chronic kidney disease

BACKGROUND

Although brain natriuretic peptide (BNP) concentration has been associated with atherosclerosis and ischemic cardiovascular diseases (CVD) in the general population, less is known about this relationship in pre-dialysis chronic kidney disease (CKD) patients.

METHODS

We prospectively analyzed 227 pre-dialysis patients with CKD [median estimated glomerular filtration rate (eGFR): 28.82 (11.65-48.20) ml/min/1.73 m(2)]. At enrollment, BNP concentrations, biochemical and echocardiographic parameters were measured, and carotid artery ultrasound was performed. Patients were prospectively followed for a mean 31.8 months (range 0.5-57.0 months). Ischemic CV events and patient outcomes were recorded.

RESULTS

Median BNP concentration at enrollment was significantly higher in the CKD patients than in a control group [53.9 (16.2-181.0) pg/ml vs. 9.4 (7.0-15.3) pg/ml, P<0.01]. BNP concentration was positively related with the carotid intima-media thickness of the common carotid artery (CCA-IMT) and left ventricular mass index (LVMI) and was significantly higher in patients with than without carotid plaques (P<0.01). Logistic regression analysis confirmed that lgBNP concentration was independently correlated with carotid plaques. Thirty-two patients experienced ischemic cardiovascular (ICV) events during follow-up. Kaplan-Meier analysis showed that cumulative survival without new ICV events was better in patients with lower than with higher BNP concentrations (P<0.01). Cox regression analysis showed that BNP was an independent risk factor for ICV events (HR=3.167, 95%CI=1.398-7.171, P<0.01).

CONCLUSIONS

Similar to findings in the general population, elevated BNP level is related to atherosclerosis and an increased risk of ICV events in pre-dialytic CKD 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.

[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.

Optimal fluid control can normalize cardiovascular risk markers and limit left ventricular hypertrophy in thrice weekly dialysis patients

Increased hemodialysis frequency can make fluid overload easier to treat, although most patients are still treated thrice weekly. Chronic fluid overload is associated with left ventricular hypertrophy and elevated serum cardiac biomarkers, recognized as mortality risk factors. Serum cardiac troponin T (cTnT), N-terminal prohormone brain natriuretic peptide (NT-proBNP), left ventricular mass index by cardiac magnetic imaging, and ambulatory blood pressure was measured in 30 thrice weekly hemodiafiltration patients. Time-averaged fluid overload (TAFO) was quantified by bioimpedance spectroscopy. In the study group, left ventricular hypertrophy was found to be 26% by cardiac magnetic resonance. Ambulatory blood pressure was 130 mmHg (112-151) requiring a low equivalent dose of medication of 0.25 units (0-1). Significantly, lower levels of left ventricular mass index (P < 0.05) were associated in those patients with TAFO <1 L or NT-proBNP <1200 pg/mL or cTnT <0.1 ug/L. In the subgroups, 16 patients had normal cTnT (<0.03 ug/L), 16 patients had NT-proBNP <400 pg/mL, and 20 patients had TAFO <1 L. Nine patients had both cTnT <0.03 ug/L and NT-proBNP <400 pg/mL. Normally hydrated thrice-weekly hemodiafiltration patients can have cardiac biomarker and TAFO levels indistinguishable from the normal healthy population. Obtaining TAFO by bioimpedance monitoring can offer a practical alternative to serum cardiac biomarkers.

Serum NT-proCNP concentrations are elevated in patients with chronic liver diseases and associated with complications and unfavorable prognosis of cirrhosis

OBJECTIVES

C-type natriuretic peptide (CNP) might be an important regulator of vasodilatation, fluid and sodium balance in liver cirrhosis. We aimed at assessing its regulation and prognostic relevance in liver disease patients.

DESIGN AND METHODS

We analyzed NT-proCNP serum levels in 193 patients with chronic liver diseases and 43 healthy controls.

RESULTS

Serum NT-proCNP concentrations were significantly elevated in liver disease patients compared to healthy controls, with highest levels in established hepatic cirrhosis, independent of disease etiology. NT-proCNP was associated with complications of liver diseases and portal hypertension, namely ascites, esophageal varices and hepatic encephalopathy. Circulating NT-proCNP correlated inversely with renal function. Importantly, elevated NT-proCNP levels were identified as a predictor of mortality or necessity for transplantation. NT-proCNP levels >2 pmol/L indicated adverse prognosis (sensitivity 66.7%, specificity 72.8%, RR 5.4 [95%-CI 2.6-11.2]).

CONCLUSIONS

Serum NT-proCNP is elevated in advanced liver diseases and has prognostic value in cirrhotic patients.

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.

Fluid overload correction and cardiac history influence brain natriuretic peptide evolution in incident haemodialysis patients

OBJECTIVES

Brain natriuretic peptide (BNP) is a cardiac peptide secreted by ventricle myocardial cells under stretch constraint. Increased BNP has been shown associated with increased mortality in end-stage renal disease patients. In patients starting haemodialysis (HD), both fluid overload and cardiac history are frequently present and may be responsible for a high BNP plasma level. We report in this study the evolution of BNP levels in incident HD patients, its relationship with fluid removal and cardiac history as well as its prognostic value.

METHODS

Forty-six patients (female/male: 21/25; 68.6 ± 14.5 years old) surviving at least 6 months after HD treatment onset were retrospectively analysed. Plasma BNP (Chemoluminescent Microparticule ImmunoAssay on i8200 Architect Abbott, Paris, France; normal value < 100 pg/mL) was assessed at HD start and during the second quarter of HD treatment (Q2).

RESULTS

At dialysis start, the plasma BNP level was 1041 ± 1178 pg/mL (range: 14-4181 pg/mL). It was correlated with age (P = 0.0017) and was significantly higher in males (P = 0.0017) and in patients with cardiac disease history (P = 0.001). The plasma BNP level at baseline was not related to the mortality risk. At Q2, predialysis systolic blood pressure (BP) decreased from 140.5 ± 24.5 to 129.4 ± 20.6 mmHg (P = 0.0001) and the postdialysis body weight by 7.6 ± 8.4% (P < 0.0001). The BNP level decreased to 631 ± 707 pg/mL (P = 0.01) at Q2. Its variation was significantly correlated with systolic BP decrease (P = 0.006). A high BNP level was found associated with an increased risk of mortality.

CONCLUSIONS

Hence, plasma BNP levels decreased during the first months of HD treatment during the dry weight quest. Whereas initial BNP values were not associated with increased mortality risk, the BNP level at Q2 was independently predictive of mortality. Hence, BNP is a useful tool to follow patient dehydration after dialysis start. Initial fluid overload may act as a confounding factor for its value as a prognostic marker because of cardiac disease.

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.

Association of B-type natriuretic Peptide levels with estimated glomerular filtration rate and congestive heart failure

BACKGROUND

The causes of elevated B-Type natriuretic peptide (BNP) levels are multifactorial. Renal dysfunction has been shown to affect BNP levels in some studies and the diagnostic value of BNP levels in the presence of chronic kidney disease has been questioned. Prior studies have involved small patient populations with variable outcomes noted. This study evaluated the association of BNP levels with an estimated glomerular filtration rate (eGFR) and presence or absence of congestive heart failure (CHF).

METHODS

A retrospective, cross-sectional study in which medical records were electronically screened, identified patients with a BNP level and serum creatinine measurement on the same day between December 2002 and March 2006.

RESULTS

Of 1739 eligible patients, 537 were positive for CHF and 1202 were negative for CHF by our criteria. There was a clear trend for BNP to be higher with the advancement of CHF, as determined by New York Heart Association (NYHA) classification (P<0.001). Median BNP levels increased from 65 pg/mL in patients without CHF to 496 pg/mL in patients with NYHA class IV CHF (P <0.001), and there was a strong inverse association with eGFR (P <0.001).

CONCLUSION

BNP levels show a strong inverse association with eGFR in both CHF and non-CHF patients. Currently best practice at most institutions involves use of BNP cutoff diagnostic levels not adjusted for eGFR. The data presented underlines that eGFR is a significant confounder of BNP measurement especially when renal status is compromised and interpretation of clinical significance in the presence of elevated BNP measures should take renal status into consideration.

The effect of renal dysfunction on BNP, NT-proBNP, and their ratio

We examined the effect of renal dysfunction on B-natriuretic peptide (BNP), N-terminal (NT)-proBNP, and their molar ratio at varying severities of cardiac function in 94 Thai patients with chest pain (52 men; 32 women), also measuring creatinine and left ventricular ejection fraction (LVEF). Renal function was classified into 5 stages by estimated glomerular filtration rate. The molar NT-proBNP/BNP ratio was calculated. Cardiac status was classified by LVEF (normal, >50%; moderate, 35%-50%; severe, <35%). BNP, NT-proBNP, and their ratio corresponded to renal disease stage exponential (0.51, 1.05, and 0.54, respectively; correlation coefficients, >or=0.95). BNP and the ratio are affected less than NT-proBNP by renal dysfunction, starting in stage III; NT-proBNP expresses effects starting in stage II. NT-proBNP is more sensitive than BNP to renal disease stage. For log of geometric means vs stage of renal disease, the BNP slopes and correlation coefficients vary considerably (slopes, 0.036-0.531; r(2), 0.017-0.99). The NT-proBNP slopes and regression coefficients vary considerably (slopes, 0.18-0.71; r(2), 0.33-0.99). For the ratio, the slopes show low variation (0.148-0.337), r(2) greater than 0.96, women differing from men (P = .012). The effect of renal disease differs by gender. BNP and NT-proBNP increase by stage III for women but not for men. One must consider renal function, gender, and LVEF when using BNP or NT-proBNP as cardiac biomarkers. The ratio of the 2 peptides is the most consistent marker across LVEFs.

Plasma concentrations of natriuretic peptides in normal cats and normotensive and hypertensive cats with chronic kidney disease

OBJECTIVES

To determine if natriuretic peptide concentrations are increased in cats with systemic hypertension and/or chronic kidney disease (CKD).

ANIMALS

22 normal cats, 13 normotensive cats with mild-moderate CKD (NT-CKD), 15 hypertensive cats with mild-moderate CKD (HT-CKD) and 8 normotensive cats with severe CKD (NT-CKD-severe).

METHODS

N-terminal pro-B-type (NT-proBNP) and pro-A-type (NT-proANP) natriuretic peptides were measured in plasma samples from all cats using commercially available assays and concentrations in the normal and diseased groups compared using non-parametric statistical tests. Spearman's rank correlation was used to test for an association between natriuretic peptide and creatinine concentrations.

RESULTS

NT-proANP was significantly higher in the NT-CKD-severe than the normal group of cats (P=0.006) but there were no other differences between groups. NT-proBNP concentrations were significantly higher in the HT-CKD group than both the normal (P<0.001) and the NT-CKD (P<0.001) groups. NT-proBNP concentrations were also higher in the NT-CKD-severe (P<0.001) and the NT-CKD (P=0.005) groups than the normal group. NT-proANP but not NT-proBNP was significantly and positively associated with plasma creatinine concentration.

CONCLUSIONS

Measurement of NT-proBNP shows promise as a diagnostic marker for systemic hypertension in the cat. Its concentration is not significantly increased in cats with mild-moderate normotensive CKD.

Assessment of the diagnostic accuracy of circulating natriuretic peptide concentrations to distinguish between cats with cardiac and non-cardiac causes of respiratory distress

OBJECTIVES

To determine if serum natriuretic peptide (NP) concentrations could distinguish cardiac from non-cardiac causes of respiratory distress (RD) in cats.

ANIMALS

Seventy-four cats from 1 university hospital were used.

METHODS

Serum NP concentrations were measured in 41 cats with non-cardiac respiratory distress (RD-NC) and compared to 33 cats with RD due to congestive heart failure (RD+CHF) using sandwich enzyme immunoassays (ELISA).

RESULTS

RD-NC cats had lower (P=0.0001) median NT-proANP and NT-proBNP concentrations (614 and 45 fmol/mL, respectively) than RD+CHF cats (1690 and 523 fmol/mL, respectively). The area under the curve was 0.88 and 0.96 for the receiver operating curve analysis of the diagnostic accuracy of NT-proANP and NT-proBNP concentrations to discriminate RD+CHF from RD-NC cats (P=0.036). An optimum cut-off concentration of 986 fmol/mL for NT-proANP and 220 fmol/mL for NT-proBNP accurately discriminated RD-NC from RC+CHF cats with a sensitivity of 93.8% and 93.9% and a specificity of 80.3% and 87.8%, respectively.

CONCLUSIONS

Serum NP concentrations were different in RD+CHF cats compared to RD-NC cats. Evaluation of circulating NP concentrations may be helpful in the initial approach to cats presenting with respiratory distress, particularly if advances in ELISA technology result in a rapid cage-side test.

Local modulation of the natriuretic peptide system in the rat remnant kidney

BACKGROUND

The natriuretic peptide (NP) system plays a central role in the renal adaptations to acute volume expansion. However, the modulation of the NP system in chronic renal insufficiency (CRI) remains to be elucidated. In the present study, we evaluated cardiac haemodynamics, plasma type-B natriuretic peptide (BNP) levels and the expression of natriuretic peptide receptor A (NPR-A) and NPR-C in the renal cortex (RC) and medulla (RM) of Sham and (3/4) nephrectomized ((3/4)nx) rats, up to 26 weeks after surgery.

METHODS

Male Wistar-Han rats (190-220 g; n = 49) were randomly assigned to (3/4)nx or Sham surgery. Two, 10 and 26 weeks after surgery, non-invasive blood pressure (BP) and left ventricular (LV) haemodynamics were performed, and urine and blood were collected for metabolic studies and plasma BNP determination. In addition, tissue samples from RC and RM were obtained for NPR-A and NPR-C quantification (RT-PCR and western blotting) as well as NPR-A immunodetection.

RESULTS

In (3/4)nx rats, the progressive interstitial fibrosis and tubular atrophy were accompanied by a time-dependent increase of BP and impaired natriuretic response to volume expansion (VE). This was accompanied in (3/4)nx rats by an early and time-dependent elevation of BNP circulating levels that was not associated with cardiac dysfunction or increased myocardial BNP gene expression. In (3/4)nx rats, NPR-A expression in the remnant RM was consistently reduced at 2, 10 and 26 weeks, and this was accompanied by an increase in NPR-C expression in the remnant RC from (3/4)nx rats.

CONCLUSIONS

BP elevation and compromised natriuretic response to VE in (3/4)nx rats is associated with increased circulating BNP levels in the absence of cardiac dysfunction. This is accompanied in (3/4)nx rats by both impaired NPR-A expression in the RM and upregulation of NPR-C in the RC suggesting a novel mechanism for NP resistance in CRI.

Relationship between serum brain natriuretic peptide and heart function in patients with chronic kidney disease

BACKGROUND/AIMS

Brain natriuretic peptide (BNP) levels are known to be elevated in patients with chronic kidney disease (CKD) and normal heart function. Therefore, the present study was performed to examine the effectiveness of BNP level in diagnosing heart failure in patients with CKD and to determine its effects on survival rate and prognosis.

METHODS

A total of 182 patients with CKD who visited the hospital due to dyspnea of NYHA class II were included in the study. BNP levels were measured and echocardiography was performed to divide the subjects into groups with and without heart failure. Their BNP levels, clinical courses, and survival rates were analyzed retrospectively.

RESULTS

When BNP level was >/=858.5 pg/mL in CKD patients, heart failure could be diagnosed with sensitivity and specificity of 77% and 72%, respectively. Survival rate of the group with BNP levels of >/=858.8 pg/mL was significantly lower than that of the group with BNP level below this threshold (p=0.012) and multivariate analysis showed that BNP level, age, and sex affected survival rate in the group with BNP level >/=858.8 pg/mL.

CONCLUSIONS

BNP levels of patients with CKD showed a positive correlation with creatinine levels, and the critical point of BNP level for diagnosis of heart failure was 858.5 pg/mL. As the survival rate in patients with BNP level above the critical point was significantly low, this level was a useful indicator for predicting their prognosis. Care should be taken in interpreting BNP level because patients with stage 5 CKD may show a high concentration of BNP without heart failure.

Cardiovascular disease in patients with chronic renal impairment: role of natriuretic peptides

Although there is overwhelming evidence that natriuretic peptides might be helpful in the diagnosis and management of congestive heart failure patients, the relationship among brain natriuretic peptides (BNP), renal function, and the severity of heart failure is less clear. It is obvious that the metabolism and elimination of BNP and N-terminal prohormone brain natriuretic peptide (NT-proBNP) are different with BNP clearance less dependent upon renal function. This paper reviews current data about the diagnostic and predictive role of natriuretic peptides to detect cardiac events in patients with chronic kidney disease. Although BNP and Nt-proBNP can be used to diagnose acute heart failure and may help predict risk and future cardiac events in patients with chronic kidney disease (CKD), a strategy that incorporates their use in daily clinical practice is still lacking.

B-type natriuretic peptides strongly predict mortality in patients who are treated with long-term dialysis

BACKGROUND AND OBJECTIVES

Left ventricular abnormalities contribute to cardiovascular disease in patients with chronic kidney disease and may be detected by measurement of B-type natriuretic peptide in serum.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a prospective cohort study of predialysis patients, patients who were on dialysis, and kidney transplant recipients, serum was collected and assayed for both B-type natriuretic peptide and its N-terminal fragment. Median levels were compared using nonparametric tests, and predictors of B-type natriuretic peptide were determined by linear regression. Survival analysis and Cox regression were performed to examine the association of levels of B-type natriuretic peptide with cardiovascular events and death.

RESULTS

Levels of B-type natriuretic peptide were highest in patients who were on dialysis. Patients who were receiving dialysis and had known cardiovascular disease, were not on the waiting list for kidney transplantation, or had left ventricular systolic dysfunction on echocardiography had significantly higher levels of B-type natriuretic peptide than patients without these characteristics. Glomerular filtration rate was an important predictor of B-type natriuretic peptide levels for patients who were not on dialysis (predialysis and renal transplant recipients). Left ventricular systolic dysfunction predicted B-type natriuretic peptide levels in patients who were on dialysis. Both forms of B-type natriuretic peptide were associated with a two- to three-fold increased risk for death in patients who were on dialysis.

CONCLUSIONS

Levels of B-type natriuretic peptide are greatest in patients who are on dialysis and have cardiovascular comorbidities and are strong predictors of death.

N-terminal prohormone brain natriuretic peptide as a predictor of cardiovascular disease and mortality in blacks with hypertensive kidney disease: the African American Study of Kidney Disease and Hypertension (AASK)

BACKGROUND

Higher levels of N-terminal prohormone brain-type natriuretic peptide (NT-proBNP) predict cardiovascular disease (CVD) in several disease states, but few data are available in patients with chronic kidney disease or in blacks.

METHODS AND RESULTS

The African American Study of Kidney Disease and Hypertension trial enrolled hypertensive blacks with a glomerular filtration rate of 20 to 65 mL x min(-1) x 1.73 m(-2) and no other identified cause of kidney disease. NT-proBNP was measured with a sandwich chemiluminescence immunoassay (coefficient of variation 2.9%) in 994 African American Study of Kidney Disease and Hypertension participants. NT-proBNP was categorized as undetectable, low, moderate, or high. Proteinuria was defined as 24-hour urinary protein-creatinine ratio >0.22. A total of 134 first CVD events (CVD death or hospitalization for coronary artery disease, heart failure, or stroke) occurred over a median of 4.3 years. Participants with high NT-proBNP were much more likely to have a CVD event than participants with undetectable NT-proBNP after adjustment (relative hazard 4.0 [95% confidence interval [CI] 2.1 to 7.6]). A doubling of NT-proBNP was associated with a relative hazard of 1.3 (95% CI 1.0 to 1.6) for coronary artery disease, 1.7 (95% CI 1.4 to 2.2) for heart failure, 1.1 (95% CI 0.9 to 1.4) for stroke, and 1.8 (95% CI 1.4 to 2.4) for CVD death. The association of NT-proBNP with CVD events was significantly stronger (P(interaction)=0.05) in participants with than in those without proteinuria. Higher NT-proBNP was not associated with renal disease progression.

CONCLUSIONS

These results suggest that elevated NT-proBNP levels are associated with higher CVD risk among blacks with hypertensive kidney disease. This association may be stronger in individuals with significant proteinuria.

Amino-terminal pro-B-type natriuretic peptide testing in renal disease

Concentrations of amino-terminal pro-B-type natriuretic peptides (NT-proBNP) are typically higher in patients with chronic kidney disease (CKD) than in those without CKD. These elevated levels of NT-proBNP in patients with CKD do not simply reflect the reduced clearance of the peptide; rather, they largely reflect a true-positive finding, identifying the presence of heart disease in these patients, while similarly indicating prognosis as well. Although modestly stronger inverse correlations exist between renal function and NT-proBNP compared with B-type natriuretic peptide (BNP), the dependence of both peptides on renal clearance is similar. Across the range of CKD, correlations between BNP and NT-proBNP remain strong, and the prognostic impact of NT-proBNP in patients with CKD is preserved. When evaluating the patient with acute dyspnea and CKD, both BNP and NT-proBNP are affected similarly, with higher decision limits necessary compared with patients with preserved renal function. Importantly, when using NT-proBNP to evaluate a patient with dyspnea and impaired renal function, the recommended cut points of 450, 900, and 1,800 ng/L for those aged <50, 50-75, and >75 years, respectively, do not require further adjustment for renal function. Thus, NT-proBNP testing remains useful for the diagnostic and prognostic evaluation of patients with CKD.

Predictive value of brain natriuretic peptides in patients on peritoneal dialysis: results from the ADEMEX trial

BACKGROUND AND OBJECTIVES

Natriuretic peptides have been suggested to be of value in risk stratification in dialysis patients. Data in patients on peritoneal dialysis remain limited.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients of the ADEMEX trial (ADEquacy of peritoneal dialysis in MEXico) were randomized to a control group [standard 4 x 2L continuous ambulatory peritoneal dialysis (CAPD); n = 484] and an intervention group (CAPD with a target creatinine clearance > or =60 L/wk/1.73 m(2); n = 481). Natriuretic peptides were measured at baseline and correlated with other parameters as well as evaluated for effects on patient outcomes.

RESULTS

Control group and intervention group were comparable at baseline with respect to all measured parameters. Baseline values of natriuretic peptides were elevated and correlated significantly with levels of residual renal function but not with body size or diabetes. Baseline values of N-terminal fragment of B-type natriuretic peptide (NT-proBNP) but not proANP(1-30), proANP(31-67), or proANP(1-98) were independently highly predictive of overall survival and cardiovascular mortality. Volume removal was also significantly correlated with patient survival.

CONCLUSIONS

NT-proBNP have a significant predictive value for survival of CAPD patients and may be of value in guiding risk stratification and potentially targeted therapeutic interventions.

Renal Dysfunction Is a Confounder for Plasma Natriuretic Peptides in Detecting Heart Dysfunction in Uremic and Idiopathic Dilated Cardiomyopathies

Background: The diagnostic value of natriuretic peptides in uremic cardiomyopathy has not been defined, nor has the effect of a hemodialysis (HD) session on peptides.

Methods: We performed an observational study of 100 white adult outpatients in New York Heart Association class I–II, with neither diabetes nor ischemic heart disease, 50 of whom had idiopathic dilated cardiomyopathy (DCM) and 50 of whom had uremic cardiomyopathy and were undergoing HD. We measured plasma N-terminal proB-type natriuretic peptide (NT-proBNP), BNP, and atrial natriuretic peptide (ANP) both before and after a dialysis session. Doppler echocardiograms were evaluated. We performed multiple regression analysis on the logarithm of peptide concentrations using clinical, laboratory, and echocardio-Doppler data as explanatory variables.

Results: Mean peptide concentrations were higher in the HD group, with an HD:DCM ratio of 25 for NT-proBNP and 5 for BNP and ANP. Peptides were correlated with each other (r &gt; 0.85). After HD, NT-proBNP significantly increased by 14%, BNP decreased by 17%, and ANP decreased by 56%. Predialysis concentrations correlated with postdialysis values (r &gt; 0.85). A multiple regression equation significantly fitted the observed peptide concentrations, both pre- and postdialysis, using the same set of 4 variables: disease group (DCM or HD), diastolic pattern, left atrial volume, and body mass index.

Conclusions: Renal dysfunction was a confounder for natriuretic peptides, which were present in higher concentrations in the uremic patients with milder cardiac dysfunction than in those with idiopathic DCM without renal dysfunction. Left diastolic function pattern and atrial volume were cardiac determinants of peptide concentrations in DCM and HD.

Diagnostic, prognostic, and therapeutic implications of brain natriuretic peptide in dialysis and nondialysis-dependent chronic renal failure

Premature cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage renal failure. Natriuretic peptides, specifically brain natriuretic peptide, are released from the heart in response to chamber distension and thus increased in the presence of volume expansion and cardiac overload. Their physiological role is to cause vasodilatation and promote natriuresis to maintain volume homeostasis. Increasingly serum levels of brain natriuretic peptide are used to both diagnose and manage cardiovascular disorders. Furthermore, augmenting the beneficial hemodynamic actions of brain natriuretic peptide may have a therapeutic role in decompensated heart failure. However, the diagnostic role of serum brain natriuretic peptide levels in patients with advanced renal dysfunction remains to be defined. These patients have a high prevalence of left ventricular disorders, specifically left ventricular hypertrophy, which may reduce the diagnostic utility of brain natriuretic peptide. In addition, ventricular stretch may be determined by intravascular volume status rather than by cardiac dysfunction. Nonetheless, as the prognosis of patients with end-stage renal failure and co-existing heart failure is so poor, the availability of a further marker of cardiac ''distress'' may in the future become a useful diagnostic tool and in due course may become a primary goal for titration and tailoring of therapy.