Plasma brain natriuretic peptide after long-term treatment for heart failure in general practice

Recombinant human brain natriuretic peptide regulates PI3K/AKT/mTOR pathway through lncRNA EGOT to attenuate hypoxia-induced injury in H9c2 cardiomyocytes

This study aimed to investigate whether recombinant human brain natriuretic peptide (rhBNP) regulated hypoxia-induced injury in H9c2 cardiomyocytes through lncRNA EGOT. H9c2 cardiomyocytes were cultured under normoxia and hypoxia (21% and 3% O₂) conditions, and whether hypoxia induced injury by assessing cell viability, apoptosis and autophagy. H9c2 cells were then treated with different doses of exogenous rhBNP (200, 600 and 900 nmol/L, respectively) and the effects of rhBNP on hypoxia-induced injury in H9c2 cells as well as the expression of EGOT were studied. In addition, the regulatory relationships between rhBNP and EGOT as well as between rhBNP and PI3K/AKT/mTOR pathway in hypoxia-treated H9c2 cells were investigated. Hypoxia significantly induced injury in H9c2 cells (inhibited cell viability and promoted cell apoptosis and autophagy) and decreased the expression of EGOT. However, administration of rhBNP alleviated hypoxia-induced injury in H9c2 cells and elevated expression of EGOT. Suppression of EGOT significantly reversed the effects of rhBNP on hypoxia-induced injury in H9c2 cells. Further studies showed that the effects of EGOT on cell viability and apoptosis were by positively regulating the expression of Cyclin D1. Moreover, rhBNP alleviated hypoxia-induced cell injury by activating PI3K/AKT/mTOR pathway in H9c2 cells. Our results reveal that rhBNP may play a protective role in attenuating hypoxia-induced injury in H9c2 cardiomyocytes via regulating lncRNA EGOT/Cyclin D1/PI3K/AKT/mTOR pathway axis. The findings will provide a new strategy for the treatment of heart failure induced by hypoxia.

A Comparison of Pathophysiology in Humans and Rodent Models of Subarachnoid Hemorrhage

Non-traumatic subarachnoid hemorrhage (SAH) affects an estimated 30,000 people each year in the United States, with an overall mortality of ~30%. Most cases of SAH result from a ruptured intracranial aneurysm, require long hospital stays, and result in significant disability and high fatality. Early brain injury (EBI) and delayed cerebral vasospasm (CV) have been implicated as leading causes of morbidity and mortality in these patients, necessitating intense focus on developing preclinical animal models that replicate clinical SAH complete with delayed CV. Despite the variety of animal models currently available, translation of findings from rodent models to clinical trials has proven especially difficult. While the explanation for this lack of translation is unclear, possibilities include the lack of standardized practices and poor replication of human pathophysiology, such as delayed cerebral vasospasm and ischemia, in rodent models of SAH. In this review, we summarize the different approaches to simulating SAH in rodents, in particular elucidating the key pathophysiology of the various methods and models. Ultimately, we suggest the development of standardized model of rodent SAH that better replicates human pathophysiology for moving forward with translational research.

Prognostic prediction in acute heart failure patients with extreme BNP values

BACKGROUND

Some patients have good prognosis despite elevated B-type natriuretic peptide (BNP), while others have ominous outcome with low BNP. We aimed at characterising these groups of patients.

METHODS

We analysed patients prospectively included in an acute HF registry. Vital status within 1-year post discharge was ascertained. A receiver-operating characteristic curve was used to define discharge BNP cut-offs for 1-year death prediction. Among survivors, we compared patients with low and not-low BNP (cut-off 400 pg/mL); and among non-survivors those with high vs not-high BNP (cut-off 2000 pg/mL). In the specific subgroups of patients with low and high BNP, mortality predictors were assessed with multivariate Cox-regression analysis.

RESULTS

We studied 584 patients, median age 78 years, 62.5% had HF with reduced ejection fraction; and 199 (34.1%) died during the first year. Non-survivors were very homogeneous irrespective of BNP, survivors were substantially different. In patients discharged with BNP <400 pg/mL, increasing age independently predicted death; when BNP ≥2000 pg/mL death predictors were higher NYHA class, and non-use of evidence-based therapy. BNP was outcome associated in both groups.

CONCLUSIONS

Different prognostic predictors may play a role in different BNP levels. We suggest that risk stratification in HF would probably be more accurate if made on top of BNP knowledge.

Clinical implications of normal B-type natriuretic peptide levels in patients with severe chronic heart failure

Background: High plasma B-type natriuretic peptide (BNP) levels in patients with severe chronic heart failure (CHF) often indicate poor ventricular function and poor prognosis. However, in some such patients plasma BNP levels are normal.

Objective: To investigate the clinical implications of BNP levels in patients with severe CHF.

Methods: Fifty-seven patients with severe CHF were divided into group A (13 normal plasma BNP level) and 44 patients (high plasma BNP levels) group B. Diuretics, angiotensin-converting enzyme inhibitors (or angiotensin II receptor antagonist, e.g., metoprolol) and digitalis were used as conventional treatment. The clinical characteristics of all patients in two groups were analyzed and compared.

Results: At the first admission, left ventricular end diastolic diameter in group B was significantly lower than group A (p < 0.05), and the plasma BNP level in group B was significantly higher than group A (p < 0.05). When metoprolol was used, 6 and 5 patients in group A and B could not tolerate the initial dose. In other cases using metoprolol at average maximum tolerance dose of metoprolol 12.5-6.25 and 24.20-11.22 mg/day in group A and B, respectively, there was a significant difference between them (p < 0.05). There were no significant differences in plasma BNP levels between two groups during stable period. The plasma BNP level in group B during acute worsening stage was significantly higher than in the remission stage (962.73-165.00 ng/L vs 876.24-167.70 ng/L, p < 0.05). However, there was no significant difference between group A (74.03-11.18 ng/L) and group B (71.38-11.68 ng/L) (p > 0.05). The mobility of group A was higher than group B (11/12 vs 6/44, p < 0.05). Logistic regression analysis showed that, the plasma BNP level was the independent risk factor for predicting cardiac death (regression coefficient, 3.817; OR, 45.488; 95% CI, 5.322ʺ388.791).

Conclusion: In patients with severe CHF, normal plasma BNP level suggests depletion of BNP secretion and further deterioration of cardiac function, indicating a poor prognosis.

Biomarkers in congenital heart disease: do natriuretic peptides hold the key?

Congenital heart disease is the most common congenital abnormality. The long-term prognosis of these patients has changed significantly over the last half century, thanks to improvements in cardiovascular diagnosis, surgery and postoperative care. However, residual lesions are not uncommon and many of the interventions performed remain palliative rather than reparative, leading to the development of ventricular dysfunction and heart failure. Natriuretic peptides are well-established markers of disease severity and prognosis in patients with heart failure due to noncongenital (acquired) heart disease. However, the role of biomarkers in congenital heart disease is unclear. This review highlights the impact of neurohormonal activation in patients with congenital heart disease, as well as the usefulness of assessing natriuretic peptide levels in specific clinical situations.

The effects of adding torasemide to standard therapy on peak oxygen consumption, natriuretic peptides, and quality of life in patients with compensated left ventricular systolic dysfunction

AIMS

Diuretics, when used to treat congestion in patients with chronic heart failure, improve symptoms and, perhaps, prognosis but little information is available to guide their use in patients with left ventricular systolic dysfunction (LVSD) who are not congested. Chronic diuretic therapy causes persistent and potentially harmful neuroendocrine activation. Alternatively, in patients in whom neuroendocrine activation is blocked with angiotensin-converting enzyme (ACE)-inhibitors and beta-blockers, diuretics may be beneficial by decreasing preload and afterload and preventing congestion. We aimed to assess the effect of the loop diuretic, torasemide on quality of life, and surrogate markers of prognosis when given to patients with LVSD who were not clinically congested and who were optimally treated with ACE-inhibitors (or angiotensin receptor antagonists) and beta-blockers.

METHODS AND RESULTS

Thirty patients with stable LVSD who had no clinically detectable fluid overload were randomized to receive either torasemide 5 mg daily or placebo for 3 months (Phase A), and after a washout phase of 2 months, cross-over was performed for 3 months (Phase B). Diuretic therapy did not cause significant change in peak VO(2), mean N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) levels, or measures of quality of life compared with placebo. Diuretic therapy did however lead to significant fall in systolic and diastolic blood pressures and increase in plasma renin levels compared with placebo.

CONCLUSION

Diuretic therapy with torasemide is not superior to placebo in improving peak VO(2) or reducing NT-proBNP levels in patients with left ventricular dysfunction who are not clinically congested.

Diagnostic accuracy of plasma brain natriuretic peptide and aminoterminal‐proBNP in mild heart failure depends on assay and introduction of therapy

OBJECTIVE

A reliable biochemical marker of left ventricular dysfunction (LVD) could improve diagnostic accuracy. The aim of this study was to compare the correlation of measurements of brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) with different assays. The diagnostic accuracy of the tests in mild heart failure (HF) was estimated before and after the start of therapy.

MATERIAL AND METHODS

Doppler echocardiography and measurements of plasma BNP and NT-proBNP were performed in 150 patients.

RESULTS

Systolic dysfunction (LV ejection fraction 0.45) was present in 22 patients, and 58 had only abnormalities in LV filling. P-NT-proBNP based on two different assays demonstrated a moderate correlation (r = 0.57, p<0.0001) and a concentration-dependent systematic difference. Excellent correlation (r = 0.95, p<0.0001) was found between BNP and NT-proBNP based on two-site antibody assays, but was moderate between BNP and a one-site antibody NT-proBNP assay (r = 0.58, p<0.0001). Areas under the receiver operating characteristic (ROC) curves (AUCs) were 0.93 (95 % CI, 0.90-0.98) for BNP, 0.95 (0.91-0.99) for NT-proBNP (two-site antibody assay) and 0.77 (0.70-0.85) for the one-site antibody NT-proBNP assay (p = 0.0001). At re-evaluation of LVD at 6 and 12 months, AUCs of BNP were 0.81 (0.74-0.99) and 0.83 (0.76-0.89), respectively, and AUCs of NT-proBNP (two-site) were 0.84 (0.77-0.91) and 0.87 (0.81-0.93), respectively. Using the baseline threshold reduced the sensitivity and specificity of BNP and NT-proBNP measurements.

CONCLUSIONS

BNP and NT-proBNP measurements demonstrated assay-dependent correlations. Measurement of p-BNP or p-NT-proBNP by a two-site antibody assay demonstrated potential as an indicator of mild, incident HF, but the applicability of the index tests was limited over time and was likely influenced by therapeutic interventions.

Neuroendocrine testing in community patients with heart disease: plasma N-terminal proatrial natriuretic peptide predicts morbidity and mortality stronger than catecholamines and heart rate variability

BACKGROUND

Patients with heart disease are at risk of developing congestive heart failure (CHF). Neurohormonal activation may make an important contribution.

AIM

In stable heart patients from primary care, to examine neuroendocrine markers of cardiac performance for the association to cardiac dysfunction, morbidity and mortality.

METHODS

Plasma N-terminal atrial natriuretic peptide (N-ANP), catecholamines, 24-h ECG and blood pressure, serum urea and creatinine, echocardiography, chest X-ray and physical examination were performed. Death was recorded during 5 to 7 years of follow-up.

RESULTS

The study included 56 patients. Mean age was 71 years, 54% were men, 43% had clinical signs of CHF, 39 + 52 + 9% were in NYHA I + II + III, 34% had echocardiographic cardiac dysfunction, and 18 died during follow-up. N-ANP was related to all subtypes of cardiac dysfunction (p < 0.05). Catecholamines and premature ventricular captures (PVC) were related to valvular and systolic dysfunction, but heart rate variability and dipping blood pressure were not (p > 0.05). On multivariate analyses only, N-ANP and PVC were associated with clinical signs of CHF, echocardiographic cardiac dysfunction, and mortality (p < 0.05).

CONCLUSIONS

Plasma N-ANP was stronger than catecholamines and variables of 24-h monitoring (blood pressure and electrocardiogram) in predicting morbidity and mortality, thereby supporting the use of cardiac natriuretic peptides (i.e. N-ANP, BNP, or N-BNP) as the most valuable biomarker in community patients at risk of CHF.

Evaluation of B-type natriuretic peptide for validation of a heart failure register in primary care

Background

Diagnosing heart failure and left ventricular systolic dysfunction is difficult on clinical grounds alone. We sought to determine the accuracy of a heart failure register in a single primary care practice, and to examine the usefulness of b-type (or brain) natriuretic peptide (BNP) assay for this purpose.

Methods

A register validation audit in a single general practice in the UK was carried out. Of 217 patients on the heart failure register, 56 of 61 patients who had not been previously investigated underwent 12-lead electrocardiography and echocardiography within the practice site. Plasma was obtained for BNP assay from 45 subjects, and its performance in identifying echocardiographic abnormalities consistent with heart failure was assessed by analysing area under receiver operator characteristic (ROC) curves.

Results

30/217 were found to have no evidence to suggest heart failure on notes review and were probably incorrectly coded. 70/112 who were previously investigated were confirmed to have heart failure. Of those not previously investigated, 24/56 (42.9%) who attended for the study had echocardiographic left ventricular systolic dysfunction. A further 8 (14.3%) had normal systolic function, but had left ventricular hypertrophy or significant valve disease. Overall, echocardiographic features consistent with heart failure were found in only 102/203 (50.2%). BNP was poor at discriminating those with and without systolic dysfunction (area under ROC curve 0.612), and those with and without any significant echocardiographic abnormality (area under ROC curve 0.723).

Conclusion

In this practice, half of the registered patients did not have significant cardiac dysfunction. On-site echocardiography identifies patients who can be removed from the heart failure register. The use of BNP assay to determine which patients require echocardiography is not supported by these data.

Prognostic value of B-type natriuretic peptide in patients with chronic and advanced heart failure

BACKGROUND

An increase in circulating B-type natriuretic peptide (BNP) is associated with a poor outcome in patients with acute heart failure. The primary aim of this study was to investigate the prognostic value of BNP levels in patients with chronic and advanced heart failure.

METHODS

Fifty patients with New York Heart Association functional classes III and IV were enrolled in the study. Their blood BNP levels at admission were measured and patients were on follow up for 12 +/- 2 months.

RESULTS

There was no significant correlation between BNP levels on admission and left ventricular ejection fraction (r = 0.12, P > 0.05). Twelve patients (24%) died during the follow up. BNP levels were lower in patients who died (501 +/- 72 vs 877 +/- 89 ng/L, P < 0.01). The logistic stepwise regression analysis showed that lower BNP level (<520 ng/L) on admission was an independent predictor of cardiovascular mortality in these patients (odds ratio 1.21, 95% confidence interval 1.06-2.32, P < 0.01).

CONCLUSION

We conclude that patients with chronic and advanced heart failure have a lower circulating BNP level than those who survive. The paradoxically low BNP level is an adverse prognostic marker in advanced heart failure.

Relation of body fluid status to B-type natriuretic peptide levels in patients with chronic heart failure during long-term follow-up

BACKGROUND

Little is known about the relationship of body fluid status with the levels and fluctuations of B-type natriuretic peptide (BNP) over the long-term.

HYPOTHESIS

If BNP is to become useful for monitoring of patients with chronic heart failure (HF), the levels should reliably reflect both decompensation and improvement in the patient's condition.

METHODS

Forty-six patients with chronic HF who were stable at study entry but had previous decompensation were recruited and followed up between June 2003 and September 2005. At each visit, they were examined for BNP level and HF-related signs of body fluid retention based on physical evaluation and pleural ultrasonography.

RESULTS

During the study period, 26 patients developed decompensation and 20 maintained a stable clinical course. In the 26 decompensated patients, BNP levels fluctuated widely (110 +/- 73.7 pg/ml; range 25-290 pg/ml) even during stable periods. In all but three patients in this group, the maximum BNP level during decompensation was higher than that reached during stable periods. The BNP levels also fluctuated widely (180 +/- 123 pg/ml; range 16-489 pg/ml) in the 20 stable patients with HF. In all but one patient in this group, the BNP level was lower than the maximum BNP level obtained during the previous decompensation.

CONCLUSIONS

In patients with chronic HF with previous decompensation, there was a strong link between the appearance of clinical HF sign(s) of fluid retention and an increased BNP level despite wide intraindividual fluctuations in BNP over time. Thus, BNP levels reliably reflect both decompensation and improvement.

B-type natriuretic peptide predicts adverse cardiovascular events in pediatric outpatients with chronic left ventricular systolic dysfunction

BACKGROUND

Plasma B-type natriuretic peptide (BNP) levels are elevated in adults with heart failure and correlate with functional classification and prognosis. The range and predictive power of BNP concentrations in children with chronic heart failure, however, are not known.

METHODS AND RESULTS

Whole blood BNP concentrations were measured in 53 consecutive patients with chronic left ventricular (LV) systolic dysfunction (biventricular hearts, ejection fraction < 50%, > 3 months since diagnosis). Children who had been hospitalized within 3 months before potential enrollment and those < 2 months or > 21 years of age were excluded. BNP concentrations were measured with the Triage assay (Biosite Diagnostics, Inc, San Diego, Calif). Echocardiographers and clinicians were blinded to BNP levels. An adverse cardiovascular event was defined as cardiac death, cardiac-related hospitalization, or listing for cardiac transplantation. The median age of patients with LV dysfunction was 9.3 years (interquartile range [IQR], 2.7 to 15.1 years). BNP levels were elevated in children with LV dysfunction compared with healthy controls (median, 78 pg/mL [IQR, 22 to 551 pg/mL] versus median, 7 pg/mL [IQR, 5 to 11 pg/mL]; P < 0.0001). Whole blood BNP concentrations were increased in patients who had a 90-day adverse cardiovascular event compared with those who did not (median, 735 pg/mL [IQR, 685 to 1510 pg/mL] versus median, 37 pg/mL [IQR, 14 to 92 pg/mL]; P < 0.001). Patients with a BNP concentration > or = 300 pg/mL were at increased risk of death, hospitalization, or listing for cardiac transplantation (adjusted hazard ratio, 63.6; P < 0.0001).

CONCLUSIONS

BNP concentrations are elevated in children with chronic LV systolic dysfunction and predict the 90-day composite end point of death, hospitalization, or listing for cardiac transplantation.

Low levels of B-type natriuretic peptide predict poor clinical outcomes in patients with chronic and advanced heart failure

B-type natriuretic peptide (BNP) is a neurohormone produced mainly by ventricular myocytes in response to increased left ventricular end-diastolic pressure. Patients with acute decompensated heart failure often have elevated plasma BNP. However, recent clinical observations have demonstrated that in patients with advanced heart failure, the plasma level of BNP is lower than those with acute heart failure. We hypothesized that a lower circulating BNP level in patients with chronic and advanced heart failure is due to the exhaustion of the biosynthesis mechanisms and is associated with a poor outcome in these patients.

NT-proBNP AND BNP VALUES IN CARDIAC PATIENTS WITH DIFFERENT DEGREE OF LEFT VENTRICULAR SYSTOLIC DYSFUNCTION

We investigated the performance of brain natriuretic peptides (BNP and NT-proBNP) in detecting various degrees of left ventricular systolic dysfunction. The NT-proBNP assay (Roche) and the BNP assay (Bayer Shionoria) were performed in 46 patients (mean age 50 years; range 20-79 years) with various types of heart disease (chronic heart failure due to coronary artery disease, cardiomyopathy, acquired valve disease, congenital heart diseases) and different impairment of left ventricular systolic dysfunction was assessed by echocardiography. Patients were divided into four groups according to the left ventricular ejection fraction (LVEF) correlated with clinical severity. Significant differences in medians of NT-proBNP and BNP values between all groups were determined (P= 0.0161 for NT-proBNP and P=0.0180 for BNP). For identifying patients with severe systolic dysfunction (LVEF<40%), receiver operating characteristic (ROC) analysis for both BNP and NT-proBNP was performed. The diagnostic performances expressed as areas under the curve were of 0.69 for NT-proBNP (cut off value 367 pg/ml) and 0.60 for BNP (cut off value 172 pg/ml). However, the BNP showed higher sensitivity (85 % vs. 63 %) and a higher positive predictive value (69 % vs 55 %) than the NT-proBNP. The negative predictive values of BNP and NT-proBNP were similar (70 % and 71 % respectively). Brain natriuretic peptides are promising markers for the diagnosis of severe left ventricular systolic dysfunction.

Elevated brain natriuretic peptide and reduced exercise capacity in adult patients operated on for tetralogy of fallot is due to biventricular dysfunction as determined by the myocardial performance index

Although tetralogy of Fallot (TOF) can be repaired surgically, residual lesions that cause abnormal ventricular load can eventually lead to heart failure. Subclinical biventricular dysfunction in these patients may be detected only by using suitably sensitive indexes. The Tei index determined by the pulsed Doppler method enables the measurement of left ventricular (LV) and right ventricular (RV) function. This study was designed to evaluate the biventricular Tei indexes in adults with operated congenital heart disease and to correlate these indexes with cardiopulmonary capacity and neurohormonal activation. Fifty-nine patients with surgically corrected TOF and 52 patients with operated left-to-right-shunt defects were included in the study. Patients with TOF showed significantly greater LV and RV Tei indexes than those with left-to-right-shunt defects (LV Tei index 0.50 +/- 0.09 vs 0.34 +/- 0.05, RV Tei index 0.37 +/- 0.1 vs 0.25 +/- 0.06; p <0.0001). Peak oxygen uptake was significantly reduced in the patients with TOF (25 +/- 6 vs 32 +/- 6 ml x kg(-1) x min(-1), p <0.0001) and was correlated inversely with the LV Tei index (r = -0.61, p <0.0001). N-terminal-pro-brain natriuretic peptide was significantly increased in patients with TOF (150 +/- 141 vs 57 +/- 39 pg/ml, p <0.0001). In conclusion, in asymptomatic or minimally symptomatic patients with TOF, biventricular dysfunction is detected by the Tei index. Further indexes for heart failure in these patients are increased circulating plasma N-terminal-pro-brain natriuretic peptide and impaired peak oxygen uptake. The combined determinations of these 3 variables enable the identification of congenital heart disease with impaired cardiac function before they become clinically symptomatic.

NT-proBNP as a marker for persistent cardiac disease in children with history of dilated cardiomyopathy and myocarditis

Children with myocarditis and dilated cardiomyopathy may recover clinically and echocardiographically. Plasma levels of the N-terminal segment of B-type natriuretic peptide prohormone (NT-proBNP), a sensitive marker for cardiac dysfunction, may reflect residual cardiac damage in these patients. The purpose of this study was to evaluate NT-proBNP status in pediatric patients with a history of myocarditis and dilated cardiomyopathy. Cardiac evaluation was performed and the levels of NT-proBNP were measured in 23 children who had a history of myocarditis or dilated cardiomyopathy. NT-proBNP levels were also measured in 56 age-matched control children. Nine of the 23 patients had evidence of left ventricular dysfunction (DCM group), whereas 14 had none (recovery). NT-proBNP levels were higher in the DCM group (3154 +/- 2858 pg/ml) than in the recovery group (122 +/- 75 pg/ml, p < 0.001) and the control group (113 +/- 96 pg/ml, p < 0.001). There was no difference between the recovery and the control groups (p = 0.45), and none of the recovered patients had a NT-proBNP level higher than the upper limit of normal. The area under the receiver operating characteristics curve for the diagnosis of persistent left ventricular dysfunction was 0.984. NT-proBNP levels correlated with echocardiographically derived shortening fraction and with clinical score. NT-proBNP is a good marker for persistent left ventricular dysfunction in children who have had myocarditis or cardiomyopathy. In this group of patients, NT-proBNP levels are normal in children who recover echocardiographically, suggesting no residual hemodynamic abnormalities.

Relation of systemic ventricular function quantified by myocardial performance index (Tei) to cardiopulmonary exercise capacity in adults after Mustard procedure for transposition of the great arteries

After Mustard repair for transposition of the great arteries, the right ventricle serves as a chronically overloaded systemic ventricle (SV). Thus, during long-term follow-up, dysfunction of the right ventricle with consecutive heart failure (HF) is not unusual. Early signs and symptoms of HF are depressed parameters of right ventricular (RV) function at rest and exercise intolerance. It was hypothesized that the measurement of RV function parameters, N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and peak oxygen uptake (VO2max) during exercise testing were suitable for the early detection of subclinical HF. In 33 asymptomatic adolescents and adults who had undergone Mustard repair, RV function was analyzed by the myocardial performance index (Tei index). NT-pro-BNP and VO2max were also determined. The corresponding data from 52 patients operated on for left-to-right shunt defects without residual lesions served as reference data. In patients who underwent the Mustard procedure, the Tei index and NT-pro-BNP were elevated (mean Tei index of the SV 0.63 +/- 0.17 vs 0.34 +/- 0.05, p <0.002; mean NT-pro-BNP 240 +/- 230 vs 57 +/- 39 pg/ml, p <0.0001), and VO2max was reduced (27 +/- 6 vs 32 +/- 6 ml x kg(-1) x min(-1), p <0.002). A good correlation was found between the Tei index and VO2max (r = -0.83, p <0.0001). In conclusion, RV function is depressed in most patients with Mustard repair. Ventricular dysfunction in such asymptomatic or minimally symptomatic patients can be detected by measurement of the Tei index, NT-pro-BNP, and VO2max. These parameters are simple and reliable screening methods to stratify patients with impaired cardiac dysfunction before they become symptomatic.

Can pro-brain natriuretic peptide be used as a noninvasive predictor of elevated left ventricular diastolic pressures in patients with normal systolic function?

OBJECTIVES

This study was sought to investigate whether plasma N-terminal pro-brain natriuretic peptide (proBNP) can help identify patients with an elevated left ventricular end-diastolic pressure (LVEDP) or filling pressures in patients with a normal systolic function.

BACKGROUND

The proBNP is a good predictor of an elevated LVEDP in patients with a systolic dysfunction. However, whether proBNP can predict an elevated LVEDP in patients with a normal systolic function remains to be determined.

METHODS

The LV pressures were measured by fluid-filled catheters in 216 patients (125 men, mean age 60 +/- 10 years) with a normal systolic function (ejection fraction 66% +/- 8%, range 50%-81%) who were undergoing diagnostic cardiac catheterization. The proBNP was sampled at the time of cardiac catheterization and was measured using a quantitative electrochemiluminescence immunoassay.

RESULTS

The log-transformed proBNP levels correlated significantly with the LVEDP (r = 0.33, P = .001) and LV pre-A-wave pressure (pre-A pressure) (r = 0.31, P = .001). An elevated proBNP, defined as >315 pg/mL, predicted an LVEDP > or = 15 mm Hg with a sensitivity of 16% and a specificity of 95% as well as a pre-A pressure > or = 15 mm Hg with a sensitivity of 36% and a specificity of 95%. However, among the 93 patients with an LVEDP > or = 15 mm Hg, 77 (83%) patients had a normal proBNP concentration (< 315 pg/mL).

CONCLUSION

The proBNP level showed weak correlations with the LVEDP and LV pre-A pressure in patients with a normal systolic function. Although high proBNP levels can predict an elevated LV diastolic pressure with high specificity, the sensitivity was quite low. Because the majority of patients with an elevated LVEDP had a normal proBNP, the proBNP level may not be suitable as a screening test for assessing LV filling pressures in the presence of normal systolic function.

Accuracy of B-type natriuretic peptide levels in the diagnosis of left ventricular dysfunction and heart failure: a systematic review

OBJECTIVES

To evaluate the accuracy of B-type natriuretic peptide levels (BNP) in the diagnosis of heart failure and left ventricular dysfunction.

DATA SOURCES

Electronic search in Medline, Embase, Cochrane Library and Medion database, and hand search of reference lists.

REVIEW METHODS

We have included published studies on the accuracy of BNP which had both sufficient information to construct the 2x2 diagnostic cross table and an appropriate spectrum of patients.

RESULTS

Fifty five studies (16,730 patients) were analyzed. The main determinants of diagnostic accuracy were the reference standard analyzed (clinical heart failure versus left ventricular dysfunction), and the methodological quality of the study. BNP levels were highly accurate for the diagnosis of clinical heart failure (diagnostic OR=41; 95% CI 23-74). The negative likelihood ratios were homogeneous, and useful for excluding the existence of heart failure (pooled negative likelihood ratio=0.11; 95% CI 0.08-0.16). The studies focused on the identification of left ventricular dysfunction were heterogeneous, with indications of publication bias, and showed less overall diagnostic accuracy than studies focused on heart failure.

CONCLUSIONS

BNP levels are useful for ruling out heart failure. The accuracy of BNP for identifying patients with systolic dysfunction is more limited.

Vascular and renal actions of brain natriuretic peptide in man: physiology and pharmacology

During the last decade brain natriuretic peptide (BNP) has received increasing attention as a potential marker of cardiovascular disease. BNP may act as a compensating mechanism in cardiovascular diseases in order to reduce preload. However, the increase in endogenous BNP is often not sufficient to compensate for volume overload in diseases like established hypertension and heart failure. The reported hemodynamic and renal effects of BNP in man differ largely between studies, because of differences in design and doses of BNP employed. In the pharmacological range, BNP has clear blood pressure and afterload lowering effects, and in the kidney blood flow and filtration is increased with concomitant natriuresis and diuresis. While in the physiological range BNP does not affect blood pressure and reduces preload only, and induces natriuresis/diuresis without changes in renal blood flow and filtration. There is increasing evidence from vascular studies that BNP preferentially acts on the venous system resulting in preload reduction, in contrast to atrial natriuretic peptide which acts preferentially on the arterial system to reduce afterload. This review summarizes our current understanding of BNP, and discuss its regulation and mechanisms of action on the vasculature and the kidneys.

Allopurinol reduces B-type natriuretic peptide concentrations and haemoglobin but does not alter exercise capacity in chronic heart failure

OBJECTIVE

To study whether the effect of allopurinol on improvement of endothelial dysfunction in chronic heart failure (CHF) translates into improved exercise capacity and to examine whether allopurinol also improves B-type natriuretic peptide (BNP), the other important prognostic marker of CHF.

DESIGN

Randomised, double blind, placebo controlled crossover trial.

SETTING

Teaching hospital.

PATIENTS

50 patients with CHF (New York Heart Association functional classes II and III) were recruited.

INTERVENTIONS

50 patients with CHF were randomly assigned to three months' treatment with allopurinol (300 mg/day) or placebo. At two and three months into treatment, they underwent a modified Bruce exercise protocol and a six minute walk test. Blood was taken for BNP and haemoglobin analysis.

RESULTS

Neither exercise test was altered by allopurinol. However, plasma BNP concentrations fell significantly (p = 0.035) with allopurinol (11.9 pmol/l) versus placebo (14.4 pmol/l). Haemoglobin concentrations also fell highly significantly with allopurinol (p = 0.001).

CONCLUSIONS

An important negative finding is that despite high hopes for it, allopurinol had no effect on exercise capacity in CHF. On the other hand, allopurinol did reduce BNP, which is the best available surrogate marker for prognosis in CHF.

NT-ProBNP in Outpatients After Myocardial Infarction: Interaction Between Symptoms and Left Ventricular Function and Optimized Cut-Points

BACKGROUND

N-terminal pro-brain natriuretic peptide (NT-proBNP) allows us to rule out left ventricular dysfunction (LVD) in the general population at a recommended cut-off concentration of 125 pg/mL. It was our objective to reassess this cut-point in outpatients after myocardial infarction.

METHODS AND RESULTS

NT-proBNP was assessed in 418 randomly selected outpatients who had experienced myocardial infarction and 352 siblings who had not experienced myocardial infarction (control). Left ventricular ejection fraction (LVEF) and mass-index (LVMI) were assessed by echocardiography. NT-proBNP was elevated in outpatients after myocardial infarction (mean [+/-SEM], 305 +/- 25 pg/mL vs control, 84 +/- 8 pg/mL; P < .01) and was correlated inversely with LVEF ( P < .001). When patients were stratified according to the presence or absence of heart failure, NT-proBNP was elevated significantly throughout all LVEF strata (each P < .05). On regression analysis, NT-proBNP was correlated independently with LVEF, LVMI, heart failure, and glomerular filtration rate (all P < .01). In patients with heart failure, the optimal cut-point for the detection of an LVEF <35% was 348 pg/mL (sensitivity 80%; specificity 69%) and for the detection of an LVEF <45% was 260 pg/mL (sensitivity 60%; specificity 60%). The relative risk for LVD in the presence of elevated NT-proBNP increased from 2.7 to 7.7 (EF < 35%) and from 1.4 to 2.4 (EF < 45%) when these cut-points were applied instead of the 125 pg/mL cut-point. An LVEF of <35% could be ruled out in symptomatic outpatients after myocardial infarction with a negative predictive value of 97% (cut-point 348 pg/mL) and in asymptomatic outpatients after myocardial infarction with a negative predictive value of 98% (cut-point 157 pg/mL).

CONCLUSION

NT-proBNP is higher in outpatients after myocardial infarction than in the general population. In symptomatic patients, a cut-point of 348 pg/mL yields satisfactory sensitivity and specificity for the detection of significant LVD (EF < 35%). Furthermore, significant LVD can be virtually ruled out in symptomatic and asymptomatic outpatients after myocardial infarction at below-threshold concentrations.

Diagnostic and Prognostic Performance of N-Terminal ProBNP in Primary Care Patients With Suspected Heart Failure

BACKGROUND

The value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in terms of diagnosis and prognosis in congestive heart failure (CHF) and left ventricular systolic dysfunction (LVSD) has been demonstrated previously in various populations, but data on primary care patients are sparse. The aim of this study was to evaluate the diagnostic and prognostic performance of NT-proBNP in primary care patients with suspected CHF.

METHODS AND RESULTS

Three hundred sixty-seven consecutive patients (mean age, 68.8 years; range, 39.0-84.0 years) who had been referred by their general practitioner for echocardiographic evaluation because of suspected CHF. In all patients, NT-proBNP was measured at baseline and left ventricular ejection fraction (LVEF) was estimated with echocardiography. LVSD (LVEF < or =0.40) was found in 9% of the patients. NT-proBNP was significantly higher in patients with LVSD (P < .0001). With predefined cut off values for NT-proBNP (125 pg/mL), the sensitivity, specificity, positive predictive value, and negative predictive value for the detection of LVSD were 0.97, 0.46, 0.15 and 0.99, respectively. Area under the receiver operating characteristic curve was 0.87. The application of an age-differentiated cut-off value for NT-proBNP (125 pg/mL for <75 years old and 450 pg/mL for > or =75 years old) did not increase diagnostic performance. Patients were followed for a median of 778 days; 8% of the patients died during the follow-up period. The mortality rate was higher in patients with NT-proBNP of >125 pg/mL than in patients with normal values (P < .002, log rank), and the difference persisted after controlling for age, gender, and LVEF (hazard ratio per unit increase in log NT-proBNP, 2.2; range, 1.2-4.1; P = .015).

CONCLUSION

In primary care patients who were referred for echocardiography because of suspected CHF, NT-proBNP values <125 pg/mL effectively rule out LVSD. Furthermore low NT-proBNP values are associated with a lower risk of death, independently of age, gender, and LVEF.

Natriuretic peptides as markers of mild forms of left ventricular dysfunction: effects of assays on diagnostic performance of markers

BACKGROUND

We compared the performance of different natriuretic peptides to diagnose mild forms of left ventricular dysfunction (LVD) and investigated the influence of measuring B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) with different assays on the diagnostic performance of these markers.

METHODS

We measured BNP (Triage BNP), NT-proBNP (Biomedica), and N-terminal pro-A-type natriuretic peptide (NT-proANP; Biomedica) in 130 consecutive patients (age range, 28-83 years) with clinically suspected mild LVD. In patients with sufficient sample volume, we measured BNP and NT-proBNP with additional assays (Shionoria and Roche, respectively).

RESULTS

For identifying patients with mild systolic LVD, BNP and NT-proBNP were the best markers, with mean (95% confidence interval) areas under the curves (AUC) of 0.78 (0.63-0.89) and 0.75 (0.58-0.87), respectively. However, the diagnostic performance of NT-proANP [AUC, 0.64 (0.48-0.77)] was significantly worse than that of BNP (P = 0.014). Both BNP assays (Triage and Shionoria) and both NT-proBNP assays (Biomedica and Roche) performed equally well for the diagnosis of systolic LVD despite the poor agreement between NT-proBNP assays. In patients with isolated diastolic LVD, the diagnostic performance of the Triage BNP [AUC, 0.70 (0.56-0.81)] was significantly better (P = 0.006) than that of Biomedica NT-proBNP [0.49 (0.34-0.65)]. Furthermore, the performance of the Biomedica NT-proBNP assay was significantly worse (P = 0.03) than that of the Roche NT-proBNP assay for diagnosis of isolated diastolic LVD.

CONCLUSIONS

The performance of BNP for the diagnosis of systolic or diastolic LVD is not affected by the assay used, whereas the performance of NT-proBNP for the diagnosis of isolated diastolic LVD is assay dependent.

N-terminal pro-B-type natriuretic peptide: reference plasma levels from birth to adolescence. Elevated levels at birth and in infants and children with heart diseases

AIM

Determination of plasma levels of N-terminal pro-B-type natriuretic peptide (N-BNP) in infants and children with and without heart diseases.

METHODS

Plasma N-BNP was measured in 78 infants and children without heart disease and in 55 infants and children with heart disease causing volume and pressure overload. Heart diseases included chronic dilated cardiomyopathy, acute left ventricular dysfunction, and congenital cardiac anomalies resulting in left and right ventricular volume or pressure overload. The Mann-Whitney rank-sum test and the ANOVA for ranks test were used to compare two or more groups, respectively.

RESULTS

N-BNP levels were elevated in the first days of life but were not significantly different in children from 4 mo to 15 y old. The upper limit in children older than 4 mo with no heart disease was 349 pg/ml. In patients with heart disease, N-BNP levels were significantly higher than in control children (p < 0.0001).

CONCLUSION

N-BNP levels are elevated in the first days of life and are stable from age 4 mo to adolescence. Elevated N-BNP levels reflect cardiac dysfunction in infants and children.

The role and assessment of ventricular peptides in heart failure

Although heart failure may be diagnosed readily in its advanced stages, it may be difficult to diagnose clinically in its early stages.Thus, there is a critical need for an inexpensive, simple, rapid,and objective test for heart failure. This article discusses the role and assessment of ventricular natriuretic peptides and related pep-tides in heart failure.

Diagnostic accuracy and prognostic relevance of the measurement of cardiac natriuretic peptides: a review

BACKGROUND

The pathophysiologic and clinical relevance of cardiac natriuretic hormone (CNH) assays has been investigated in numerous experimental and clinical studies. Authors have sought to evaluate the diagnostic accuracy and prognostic relevance of the measurement of CNHs according to evidence-based laboratory medicine principles.

METHODS

In June 2003, we ran a computerized literature search on National Library of Medicine using keywords "ANP" and "BNP" and found more than 12 300 and 1200 articles, respectively. A more refined search with keywords "ANP or BNP assay" extracted approximately 7000 and 800 articles, respectively. Only studies specifically designed to evaluate the diagnostic accuracy and prognostic relevance of CNH measurements were selected from this huge mass of articles to be discussed in this review.

CONTENT

Several studies suggested that CNH assays may be clinically useful for the screening and classification of patients with heart failure, as a prognostic marker in cardiovascular disease, in the follow-up of patients with heart failure, and because they may reduce the need for further cardiac investigation. However, it is difficult to compare even the best-designed studies because not only did the authors evaluate different populations, they also used different gold standards.

CONCLUSIONS

CNH assays and conventional diagnostic work-ups provide complementary information for evaluation of the presence and severity of cardiac dysfunction and clinical disease. Several aspects of CNH assays are still to be elucidated, and further work is needed to carefully assess their diagnostic accuracy and prognostic value in cardiac disease.

Cardiac hormones as diagnostic tools in heart failure

In patients with heart failure, plasma levels of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and the N-terminal fragments of their prohormones (N-ANP and N-BNP) are elevated, because the cardiac hormonal system is activated by increased wall stretch due to increased volume and pressure overload. Patients suspected of having heart failure can be selected for further investigations on the basis of having an elevated plasma concentration of N-ANP, BNP, and N-BNP. High levels of cardiac hormones identify those at greatest risk for future serious cardiovascular events. Moreover, adjusting heart failure treatment to reduce plasma levels of N-BNP may improve outcome. Cardiac hormones are most useful clinically as a rule-out test. In acutely symptomatic patients, a very high negative predictive value is coupled with a relatively high positive predictive value. Measurement of cardiac hormones in patients with heart failure may reduce the need for hospitalizations and for more expensive investigations such as echocardiography. However, there have also been conflicting reports on the diagnostic value of cardiac hormones, they are not specific for any disease, and the magnitude of the effects of age and gender on BNP in the normal subgroup suggests that these parameters need to be considered when interpreting cardiac hormone levels.