B-type natriuretic peptide: a critical review

Effect of bioelectrical impedance technology on the prognosis of dialysis patients: a meta-analysis of randomized controlled trials

Managing patient 'dry weight' according to clinical standards has deficiencies. Research has focused on the effectiveness of using bioelectrical impedance technology for fluid management in dialysis patients. Whether bioelectrical impedance monitoring can improve dialysis patients prognoses remain controversial. We performed a meta-analysis of randomized controlled trials to determine whether bioelectrical impedance was effective in improving dialysis patients prognoses. The primary outcome was all-cause mortality (13.6 ± 9.1 months). Secondary outcomes were left ventricular mass index (LVMI), arterial stiffness assessed using Pulse Wave Velocity (PWV), and N-terminal brain natriuretic peptide precursor (NT-proBNP). Of 4,641 citations retrieved, we identified 15 eligible trials involving 2763 patients divided into experimental (n = 1386) and control (n = 1377) groups. In 14 studies with mortality data, the meta-analysis showed that bioelectrical impedance intervention reduced the risk of all-cause mortality (rate ratios [RR]: 0.71; 95% confidence interval [CI]: 0.51, 0.99; p = .05; I2 = 1%). Subgroup analysis of patients on hemodialysis (RR: 0.72; 95% CI: 0.42, 1.22; p = .22) and peritoneal dialysis (RR: 0.62; 95% CI: 0.35, 1.07; p = .08) showed no significant mortality difference between intervention and control groups. It reduced the risk of all-cause mortality in the Asian population (RR: 0.52; p = .02), and reduced NT-proBNP (mean difference [MD]: -1495.73; p = 0.002; I²=0%) and PWV (MD: -1.55; p = .01; I²=89%). Bioelectrical impedance intervention reduced the LVMI in hemodialysis patients (MD: -12.69; p < .0001; I²=0%). Our analysis shows that in dialysis patients, bioelectrical impedance technology intervention could reduce, but not eliminate, the risk of all-cause mortality. Overall, this technology can improve the prognosis of dialysis patients.

NT-proBNP Qualifies as a Surrogate for Clinical End Points in Heart Failure

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a well-established biomarker in heart failure (HF) but controversially discussed as a potential surrogate marker in HF trials. We analyzed the NT-proBNP/mortality relationship in real-world data (RWD) of 108,330 HF patients from the IBM Watson Health Explorys database and compared it with the NT-proBNP / clinical event end-point relationship in 20 clinical HF studies. With a hierarchical statistical model, we quantified the functional relationship and interstudy variability. To independently qualify the model, we predicted outcome hazard ratios in five phase III HF studies solely based on NT-proBNP measured early in the respective study. In RWD and clinical studies, the relationship between NT-proBNP and clinical outcome is well described by an Emax model. The NT-proBNP independent baseline risk (R0 , RWD/studies median (interstudy interquartile range): 5.5%/3.0% (1.7-4.9%)) is very low compared with the potential NT-proBNP-associated maximum risk (Rmax : 55.2%/79.4% (61.5-89.0%)). The NT-proBNP concentration associated with the half-maximal risk is comparable in RWD and across clinical studies (EC50 : 3,880/2,414 pg/mL (1,460-4,355 pg/mL)). Model-based predictions of phase III outcomes, relying on short-term NT-proBNP data only, match final trial results with comparable confidence intervals. Our analysis qualifies NT-proBNP as a surrogate for clinical outcome in HF trials. NT-proBNP levels after short treatment durations of less than 10 weeks quantitatively predict hazard ratios with confidence levels comparable to final trial readout. Early NT-proBNP measurement can therefore enable shorter and smaller but still reliable HF trials.

Point-of-care testing (POCT) and evidence-based laboratory medicine (EBLM) - does it leverage any advantage in clinical decision making?

Point-of-care testing (POCT) is the analysis of patient specimens outside the clinical laboratory, near or at the site of patient care, usually performed by clinical staff without laboratory training, although it also encompasses patient self-monitoring. It is able to provide a rapid result near the patient and which can be acted upon immediately. The key driver is the concept that clinical decision making may be delayed when samples are sent to the clinical laboratory. Balanced against this are considerations of increased costs for purchase and maintenance of equipment, staff training, connectivity to the laboratory information system (LIS), quality control (QC) and external quality assurance (EQA) procedures, all required for accreditation under ISO 22870. The justification for POCT depends upon being able to demonstrate that a more timely result (shorter turnaround times (TATs)) is able to leverage a clinically important advantage in decision making compared with the central laboratory (CL). In the four decades since POCT was adapted for the self-monitoring of blood glucose levels by subjects with diabetes, numerous new POCT methodologies have become available, enabling the clinician to receive results and initiate treatment more rapidly. However, these instruments are often operated by staff not trained in laboratory medicine and hence are prone to errors in the analytical phase (as opposed to laboratory testing where the analytical phase has the least errors). In some environments, particularly remote rural settings, the CL may be at a considerable distance and timely availability of cardiac troponins and other analytes can triage referrals to the main centers, thus avoiding expensive unnecessary patient transportation costs. However, in the Emergency Department, availability of more rapid results with POCT does not always translate into shorter stays due to other barriers to implementation of care. In this review, we apply the principles of evidence-based laboratory medicine (EBLM) looking for high quality systematic reviews and meta-analyses, ideally underpinned by randomized controlled trials (RCTs), looking for evidence of whether POCT confers any advantage in clinical decision making in different scenarios.

Factors affecting N-terminal pro-brain natriuretic peptide elevation in the acute phase of Kawasaki disease

BACKGROUND

The aim of this study was to investigate the clinical significance and factors that affect N-terminal pro-brain natriuretic peptide (NT-proBNP) elevation in the acute phase of Kawasaki disease (KD) despite the absence of apparent cardiac complications.

METHODS

The laboratory and echocardiography results of 44 KD patients in the acute and subacute phases were reviewed.

RESULTS

With preserved cardiac function, median NT-proBNP was significantly elevated in the acute phase compared with the subacute phase (343 pg/mL, IQR, 162-1182 pg/mL vs 98 pg/mL, IQR, 61-205 pg/mL, respectively; P < 0.0001). The respective levels of tumor necrosis factor (TNF)-α, soluble TNF receptor (sTNFR)1, and sTNFR2 were also significantly elevated in the acute phase compared with the subacute phase: TNF-α, 3.3 pg/mL (IQR, 2.6-4.8 pg/mL) versus 2.4 pg/mL (IQR 1.9-4.0 pg/mL; P < 0.01), sTNFR1, 2741 pg/mL (IQR, 2080-3183 pg/mL) versus 976 pg/mL (IQR, 814-1247 pg/mL; P < 0.0001), sTNFR2, 5644 pg/mL (IQR, 4693-7520 pg/mL) versus 3169 pg/mL (IQR, 2132-3878 pg/mL; P < 0.0001). Log-transformed NT-proBNP was correlated with TNF-α (r = 0.29, P = 0.056), sTNFR1 (r = 0.60, P < 0.0001), and sTNFR2 (r = 0.65, P < 0.0001). TNF-α was correlated with sTNFR1 (r = 0.35, P = 0.02) and sTNFR2 (r = 0.51, P < 0.001).

CONCLUSION

Tumor necrosis factor-α may cause NT-proBNP elevation in the acute phase of KD, and NT-proBNP level may be an indicator of TNF-α activity.

Pro-brain natriuretic peptide (ProBNP) levels in North Indian children with Kawasaki disease

The diagnosis of Kawasaki disease (KD), a common pediatric vasculitis, is based solely on clinical criteria. There is a need for a robust laboratory marker that can help differentiate KD from other acute, febrile, childhood illnesses and also to predict cardiac involvement. We conducted a cross-sectional study of 25 consecutive patients admitted with diagnosis of KD from January 2013 to April 2014 and compared them with age- and sex-matched febrile controls. We studied the serum pro-brain natriuretic peptide (ProBNP) [ProBNP and N-terminal pro-B-type natriuretic peptide (NT-ProBNP) levels], a marker of myocardial dysfunction, in children with KD in acute and convalescent phases of disease. These levels were also estimated in febrile controls for comparison. The ProBNP (ProBNP and NT-ProBNP) levels were much higher in the acute phase of the KD patients compared to levels in the convalescent phase of KD (p = 0.000014). Similarly, the levels in the acute phase were higher when compared to the age- and sex-matched febrile controls (p = 0.000126). The receiver operating curve (ROC) analysis for the ProBNP levels in the acute phase of KD yielded an area under the curve of 0.954 ± 0.034 (p < 0.000, 95 % CI 0.886-1.0). Based on ROC analysis, a cutoff of 1025 pg/mL for ProBNP levels in the acute phase of KD had 88 % sensitivity and 96 % specificity for the diagnosis of KD. A lower cut-off of 514 pg/mL yielded a 100 % sensitivity and 80 % specificity for the diagnosis of KD. The ProBNP levels were higher in those with coronary artery abnormalities (CAA) compared to those without CAA in both acute (p = 0.013) and convalescent (p = 0.045) phases. ProBNP levels may be used as a surrogate marker for the differentiation of KD from other febrile, infectious illnesses and may also predict the involvement of coronary arteries.

N-terminal pro-brain natriuretic peptide in acute Kawasaki disease correlates with coronary artery involvement

BACKGROUND

We have lately documented the importance of N-terminal pro-brain natriuretic peptide in aiding the diagnosis of Kawasaki disease.

OBJECTIVES

We sought to investigate the potential value of N-terminal pro-brain natriuretic peptide pertaining to the prediction of coronary artery dilatation (Z-score>2.5) and/or of resistance to intravenous immunoglobulin therapy. We hypothesised that increased serum N-terminal pro-brain natriuretic peptide level correlates with increased coronary artery dilatation and/or resistance to intravenous immunoglobulin.

METHODS

We carried out a prospective study involving newly diagnosed patients treated with 2 g/kg intravenous immunoglobulin within 5-10 days of onset of fever. Echocardiography was performed in all patients at onset, then weekly for 3 weeks, then at month 2, and month 3. Coronary arteries were measured at each visit, and coronary artery Z-score was calculated. All the patients had N-terminal pro-brain natriuretic peptide serum level measured at onset, and the Z-score calculated.

RESULTS

There were 109 patients enrolled at 6.58±2.82 days of fever, age 3.79±2.92 years. High N-terminal pro-brain natriuretic peptide level was associated with coronary artery dilatation at onset in 22.2 versus 5.6% for normal N-terminal pro-brain natriuretic peptide levels (odds ratio 4.8 [95% confidence interval 1.05-22.4]; p=0.031). This was predictive of cumulative coronary artery dilatation for the first 3 months (p=0.04-0.02), but not during convalescence at 2-3 months (odds ratio 1.28 [95% confidence interval 0.23-7.3]; p=non-significant). Elevated N-terminal pro-brain natriuretic peptide levels did not predict intravenous immunoglobulin resistance, 15.3 versus 13.5% (p=1).

CONCLUSION

Elevated N-terminal pro-brain natriuretic peptide level correlates with acute coronary artery dilatation in treated Kawasaki disease, but not with intravenous immunoglobulin resistance.

N-terminal pro-brain natriuretic peptide (NT proBNP) as a predictive indicator of initial intravenous immunoglobulin treatment failure in children with Kawasaki disease: a retrospective study

Intravenous immunoglobulin (IVIG) administered in the acute stage of Kawasaki disease (KD) is the standard therapy. Few reports describe nonresponders to initial treatment with IVIG in KD, which remains the most consistent risk factor for coronary artery lesions (CALs). This study aimed to investigate whether the serum level of N-terminal pro-brain natriuretic peptide (NT-proBNP) can be a predictive indicator for identifying patients with KD at higher risk of IVIG treatment failure. In this study, 135 patients with a diagnosis of KD admitted for IVIG treatment were retrospectively enrolled for analysis. Of these 135 patients, 22 were nonresponders who received additional rescue therapy because they had an elevated body temperature 36 h after completion of initial IVIG treatment. The NT-proBNP concentration was significantly higher in the nonresponder group (2,465.36 ± 3,293.24 pg/mL) than in the responder group (942.38 ± 1,293.48 pg/mL) (p < 0.05). The optimal sensitivity and specificity cutoff point for predicted nonresponders was 1,093.00 pg/mL or higher. The sensitivity and specificity for prediction of IVIG response were respectively 70.0 and 76.5 %. The findings show that NT-proBNP is a helpful marker in determining patients at risk for not responding to initial IVIG treatment. The authors suggest that patients with an NT-proBNP level of 1,093.00 pg/dL or higher are likely to fail initial IVIG and may require further rescue therapy.

B-type natriuretic peptide and N-terminal pro-BNP in the acute phase of Kawasaki disease

BACKGROUND

This study was undertaken to identify factors correlating with plasma levels of B-type natriuretic peptide (BNP) and its N-terminal portion (NTpro BNP) in the acute phase of Kawasaki disease (KD).

METHODS

This study included 91 patients with KD treated at a hospital affiliated to Hamamatsu University School of Medicine between October 2003 and June 2011. We quantified BNP and NT-pro BNP in the acute phase. The BNP level was expressed as the NT-pro BNP level using the formula NT-pro BNP=9.080×BNP(0.923). We sought relationships between NT-pro BNP values and different clinical and laboratory data in the acute phase of KD.

RESULTS

Of the 91 patients, 14 failed to respond to the initial intravenous immunoglobulins therapy. NTpro BNP levels were significantly higher in these nonresponders than in the responders (1689.3±1168.8 pg/ dL vs. 844.4±1276.3 pg/dL, P<0.001). Seventeen patients developed coronary artery lesions, but this was not associated with NT-proBNP levels. NT-pro BNP was positively correlated with CRP (r=0.421, P<0.001) and negatively correlated with the hematocrit (r=-0.206, P=0.050), Na value (r=-0.214, P=0.041) and albumin level (r=-0.345, P<0.001). Stepwise multiple linear regression analysis with NT-pro BNP as a dependent variable revealed significant correlations with CRP and albumin (beta=0.345, P=0.001; beta=-0.225, P=0.027).

CONCLUSIONS

A high level of NT-pro BNP in acute phase KD is associated with systemic inflammatory responses and increased vascular permeability. The NT-pro BNP level is a useful marker to identify potential non-responders to IVIG among KD patients.

Usefulness of cardiac biomarker score for risk stratification in stable patients undergoing elective cardiac evaluation across glycemic status

Several clinically available cardiac biomarkers have established their prognostic value in patients with acute coronary syndromes. However, their relative prognostic significance in stable subjects has not been prospectively validated, either individually or in combination. The aim of this study was to evaluate the extent to which B-type natriuretic peptide, myeloperoxidase, and high-sensitivity C-reactive protein alone or together could be prognostic biomarkers in 3,635 consecutive stable patients without acute coronary syndrome who underwent elective diagnostic coronary angiography. After adjusting for traditional risk factors and renal function, each of the markers monitored was a significant predictor of incident major adverse cardiovascular events (death, nonfatal myocardial infarction, and stroke) over 3 years. A cardiac biomarker score based on the sum total of "positive" biomarkers provided independent prediction of future risk for incident major adverse cardiovascular events at 3 years (hazard ratio [HR] 7.61, 95% confidence interval [CI] 4.98 to 11.65, p <0.001), even after adjusted for traditional risk factors (HR 6.11, 95% CI 3.98 to 9.38, p <0.001). A positive cardiac biomarker score remained a strong and independent predictor of 3-year risk for major adverse cardiovascular events among those with normal glycemic control (HR 4.24, 95% CI 1.96 to 9.18, p <0.001), those with prediabetes (HR 7.62, 95% CI 3.87 to 15.01, p <0.001), and those with diabetes (HR 5.61, 95% CI 2.55 to 12.33, p <0.001), as well as within subjects without significant angiographic evidence of coronary artery disease (HR 10.82, 95% CI 3.82 to 30.6, p <0.001). In conclusion, an integrated assessment of cardiac biomarkers may provide independent prognostic value for long-term adverse clinical events in stable cardiac patients.

Natriuretic Peptides in Kawasaki Disease: the Myocardial Perspective

Making a diagnosis of Kawasaki disease with certainty may be challenging, especially since the recognition of cases with incomplete diagnostic criteria and its consequences. In order to build the diagnostic case in daily practice, clinicians rely on clinical criteria established over four decades ago, aided by non specific laboratory tests, and above all inspired by experience. We have recently studied the diagnostic value of N-terminal pro B-type natriuretic peptide to improve the diagnostic certainty of cases with complete or incomplete clinical criteria. Our working hypothesis was based on the fact that myocarditis is present in nearly all Kawasaki disease patients supported by histology data. In this paper, we review these facts and the myocardial perspective from the diagnostic and the mechanistic standpoints.

Prediction of the risk of coronary arterial lesions in Kawasaki disease by brain natriuretic peptide

Kawasaki disease (KD) is an acute systemic vasculitis associated with the development of coronary arterial lesions (CALs) occurring in 3-5% of children treated by intravenous immune globulin (IVIG). However, a considerable number of patients who are not responding to IVIG are at much higher risk. Although studies have explored potential biomarkers to predict patients with KD who are at risk of CAL, no useful single marker exists. We hypothesized that the serum concentrations of the N-terminal moiety of brain natriuretic peptide (NT-proBNP) can be useful to predict CAL. Forty-three children with KD (29 males and 14 females) were enrolled in this study. Despite IVIG, 6 of the 43 patients developed CAL. There were, however, no significant differences in variables between children with CAL and those without CAL: These include age, gender, day of the illness, leukocyte count, and the serum levels of sodium, C-reactive protein, and albumin. The serum NT-proBNP level was significantly higher in children with CAL than those without CAL (2,611 ± 1,699 vs. 1,073 ± 1,427 pg/ml; P = 0.03): the cutoff value of 1,000 pg/ml to predict CAL produced a specificity of 0.68, sensitivity of 0.83, and an odds ratio as high as 10.4. In conclusion, NT-proBNP is increased in KD patients who are developing CAL, and patients with an elevated serum NT-proBNP >1,000 pg/ml have a risk of CAL ~10 times higher than that of patients with a modest increase.

Accuracy of plasma B-type natriuretic peptide to diagnose significant cardiovascular disease in children: the Better Not Pout Children! Study

OBJECTIVES

The purpose of this study was to assess the ability of plasma B-type natriuretic peptide (BNP) to diagnose significant cardiovascular disease (CVD) in the pediatric population.

BACKGROUND

BNP has been shown to be reliable in detecting ventricular dysfunction and heart failure in adults. Timely and accurate identification of significant pediatric heart disease is important but challenging. A simple blood test could aid the front-line physician in this task.

METHODS

Subjects without a history of heart disease with findings possibly attributable to significant CVD in the acute care setting requiring a cardiology consult were enrolled. Clinicians were blinded to the BNP result, and confirmation of disease was made by cardiology consultation.

RESULTS

Subjects were divided into a neonatal (n = 42, 0 to 7 days) and older age group (n = 58, >7 days to 19 years). CVD was present in 74% of neonates and 53% of the older age group. In neonates with disease, median BNP was 526 pg/ml versus 96 pg/ml (p < 0.001) for those without disease. In older children with disease, median BNP was 122 pg/ml versus 22 pg/ml in those without disease (p < 0.001). Subjects with disease from an anatomic defect, a longer hospital stay, or who died had higher BNP. A BNP of 170 pg/ml yielded a sensitivity of 94% and specificity of 73% in the neonatal group and 87% and 70% in the older age group, respectively, using a BNP of 41 pg/ml.

CONCLUSIONS

BNP is a reliable test to diagnose significant structural or functional CVD in children. Optimal cutoff values are different from adult values.