BNP and congestive heart failure

Brain natriuretic peptide (BNP), a peptide hormone secreted chiefly by ventricular myocytes, plays a key role in volume homeostasis. The plasma concentration of BNP is raised in various pathological states, especially heart failure. Many studies suggest that measurement of plasma BNP has clinical utility for excluding a diagnosis of heart failure in patients with dyspnea or fluid retention and for providing prognostic information in those with heart failure or other cardiac disease. It may also be of value in identifying patients after myocardial infarction in whom further assessment of cardiac function is likely to be worthwhile. Preliminary evidence suggests that measuring the plasma concentration of BNP may be useful in fine tuning therapy for heart failure. Artificially raising the circulating levels of BNP shows considerable promise as a treatment for heart failure. With simpler assay methods now available, it is likely that many physicians will measure plasma BNP to aid them in the diagnosis, risk stratification, and monitoring of their patients with heart failure or other cardiac dysfunction.     

Natriuretische Peptide—neue diagnostische Marker bei Herzerkrankungen

In patients with heart failure, increased wall stretch due to volume and pressure overload leads to an increase in circulating natriuretic peptides (ANP and BNP and their N-terminal fragments NT-proANP and NT-proBNP). Plasma BNP levels commonly considered normal (< 20 pg/ml) are influenced by age, sex, and also by genetic factors. ANP and BNP are synthesized and released by atrial and ventricular myocytes (Figure 1).In subjects with acute dyspnea, a BNP plasma concentration of 100 pg/ml has been established as a cutoff value for the diagnosis of heart failure yielding a very high negative predictive value coupled with an acceptable positive predictive value (Figure 3). However, recent evidence suggests that much more subtle elevations of plasma BNP may also indicate an increased long-term risk of cardiovascular events and death (Figure 2). In acute heart failure, natriuretic peptides correlate with ventricular pressure and volume overload, as well as with NYHA functional class. They can, however, not reliably discriminate between heart failure due to reduced ejection fraction and heart failure with preserved systolic function (Figure 4). Thus, elevated BNP or NT-proBNP levels always demand further clarification of heart failure etiology using echocardiography as the method of choice. As indicated by the algorithm for a BNP-based differential diagnosis of acute heart failure symptoms (Figure 5), a variety of noncardiac causes may also lead to moderate elevations of the markers (BNP plasma concentrations of 100-400 pg/ml). In addition, normal marker levels may be observed in > 20% of patients with long-term stable heart failure. Thus, increased plasma concentrations of natriuretic peptides are not strictly specific for heart diseases and also lack sensitivity in the chronic compensated state. Diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor antagonists, and spironolactone have been shown to decrease BNP and NT-proBNP in parallel with clinical and hemodynamic improvement. In patients hospitalized for decompensated heart failure, predischarge plasma BNP levels reflect the risk of future death and rehospitalization (Figure 6). Although adjusting heart failure treatment to reduce plasma NT-proBNP levels may improve outcome, a general recommendation for monitoring drug therapy using this marker should not be derived from this observation.General practitioners may, in the future, use BNP or NT-proBNP as a rule-out test for heart failure and preselect patients for further diagnostic work-up on the basis of an elevated plasma level. Within the framework of the German network for heart failure the multicentric "Handheld-BNP Study" will clarify, whether echocardiography using low-price simple handcarried devices could be used as an alternative or, more likely, as a complementary diagnostic tool to further improve heart failure diagnosis in primary care.     

B-type natriuretic peptide in heart failure

PURPOSE OF REVIEW: This review focuses on recent literature pertaining to the role of B-type natriuretic peptide (BNP) in heart failure. RECENT FINDINGS: Heart failure is a common disorder that is associated with significant mortality and morbidity. The diagnosis of heart failure may at times be difficult when using conventional tools. The cardiac natriuretic peptides, particularly BNP, have evolved to be useful biomarkers in heart failure and other cardiovascular disorders. Recent studies have established a close association between plasma BNP and the amino-terminal fragment of the BNP prohormone (NT-proBNP) with the diagnosis of heart failure and independent prediction of mortality and heart failure events. Furthermore, preliminary data from randomized controlled trials suggest that knowledge of BNP and/or NT-proBNP level may optimize the management of patients with heart failure. Exogenous natriuretic peptide in the form of recombinant human BNP (nesiritide) has been shown to improve hemodynamics and dyspnea and is approved in the USA and several other countries for the management of patients with acute decompensated heart failure. The effect of nesiritide on clinical outcome, however, remains unclear. SUMMARY: When used in the appropriate clinical settings, BNP or NT-proBNP testing is extremely useful in establishing diagnosis and predicting prognosis in heart failure. Nesiritide holds promise in the management of patients with acute decompensated heart failure. Large-scale randomized controlled trials to evaluate BNP/NT-proBNP-guided therapy are currently in progress and studies of the impact of exogenous BNP on clinical outcomes in heart failure are likely to be forthcoming.     

慢性阻塞性肺部疾病合并充血性心力衰竭患者B型脑钠肽的变化及临床意义

目的探讨慢性阻塞性肺部疾病（COPD）合并充血性心力衰竭（CHF）患者血浆B型脑钠肽（BNP）水平的变化及临床意义。方法选择120例COPD患者作为研究对象,其中COPD合并CHF组54例,COPD急性发作（AECOPD）组66例,选择健康体检正常者36例作为对照组,采用免疫荧光法快速测定BNP水平。比较三组间血浆BNP水平的差异。COPD合并CHF患者治疗好转后复查血浆BNP水平,比较治疗前、后血浆BNP水平的变化。结果COPD合并CHF组和AECOPD组血浆BNP水平分别为（798．41±231．64）pg／ml和（148．73±87．39）pg／ml;对照组血浆BNP水平为（46．83±15．54）pg／ml。COPD合并CHF患者与对照组及AECOPD患者比较,血浆BNP水平差异均有统计学意义（P〈0．01）;治疗后血浆BNP水平[（136．73±64．82）pg／ml]与治疗前比较明显下降（P〈0．01）。结论血浆BNP水平测定对COPD合并CHF患者有重要的鉴别诊断价值,可作为COPD合并CHF患者治疗效果的评价指标。     

脑利钠肽在心力衰竭诊治中的研究进展

脑利钠肽 (Brain/B typenatriureticpeptide ,BNP)是一种主要由心室分泌的神经激素 ,可反应心室压力负荷与容量负荷的变化。BNP测定有助于心力衰竭的诊断及预后评价 ,并可指导心力衰竭的治疗。但BNP检测应该结合临床而不应该作为一种孤立的指标。     

脑钠素对老年人心力衰竭诊断和预后评估的价值

目的探讨脑钠素(BNP)对老年人心力衰竭诊断和预后评估的价值。方法选择老年无症状性心力衰竭患者21例(aSHF组)和老年症状性心力衰竭患者42例(SHF组),另选18例健康老年人作为对照组,采用放射免疫分析法测定各组血浆BNP水平;比较各组血浆BNP水平和心功能状况及心血管事件发生的关系。结果血浆BNP水平在对照组、aSHF组、SHF组呈递增趋势,且随着纽约心功能分级(NYHA)增高而增加;血浆BNP为70 ng/L时,对诊断aSHF的灵敏度、特异度分别为90.48%、94.44%;根据左心室射血分数值、NYHA、BNP水平3种分级法与专家分级法符合率分别为81.9%、73.0%、85.7%;NYHAⅢ级和NYHAⅣ级患者心血管事件的发生率明显高于aSHF组和NYHAⅡ级患者,发生心血管事件患者的血浆BNP水平高于而LVEF值低于未发生心血管事件的患者。结论血浆BNP水平能反映心力衰竭的严重程度,与左心室的结构和功能相关,检测血浆BNP水平对于aSHF的诊断和鉴别诊断有重要的临床价值,且对于心力衰竭患者近期发生心血管事件具有重要的预测意义。     

Brain natriuretic peptide is a predictor of anthracycline-induced cardiotoxicity

Anthracyclines are effective antineoplastic drugs, but they frequently cause dose-related cardiotoxicity. The cardiotoxicity of conventional anthracycline therapy highlights a need to search for methods that are highly sensitive and capable of predicting cardiac dysfunction. We measured the plasma level of brain natriuretic peptide (BNP) to determine whether BNP might serve as a simple diagnostic indicator of anthracycline-induced cardiotoxicity in patients with acute leukemia treated with a daunorubicin (DNR)-containing regimen. Thirteen patients with acute leukemia were treated with a DNR-containing regimen. Cardiac functions were evaluated with radionuclide angiography before chemotherapies. The plasma levels of atrial natriuretic peptide (ANP) and BNP were measured at the time of radionuclide angiography. Three patients developed congestive heart failure after the completion of chemotherapy. Five patients were diagnosed as having subclinical heart failure after the completion of chemotherapy. The plasma levels of BNP in all the patients with clinical and subclinical heart failure increased above the normal limit (40 pg/ml) before the detection of clinical or subclinical heart failure by radionuclide angiography. On the other hand, BNP did not increase in the patients without heart failure given DNR, even at more than 700 mg/m(2). The plasma level of ANP did not always increase in all the patients with clinical and subclinical heart failure. These preliminary results suggest that BNP may be useful as an early and sensitive indicator of anthracycline-induced cardiotoxicity.     

No incremental clinical information of NT Pro BNP at peak exercise over resting levels in patients with impaired left ventricular function

There is an increasing tension to use NT Pro BNP blood levels at peak exercise testing. Their possible superiority over resting levels in congestive heart failure or factors associated with their increase have not been adequately studied. We studied 65 patients, 51 males and 14 females with impaired left ventricular function. Mean left ventricular ejection fraction (LVEF) was 35+/-9%. Our findings suggest that in patients with heart failure NT Pro BNP plasma levels at peak exercise do not provide incremental clinical information over resting levels. Baseline NT Pro BNP alone can provide sufficient clinical information.     

Decreased plasma concentration of brain natriuretic peptide as a potential indicator of cardiac recovery in patients supported by mechanical circulatory assist systems

OBJECTIVES

We sought to investigate the relationship between the plasma concentration of brain natriuretic peptide (BNP), echocardiographic findings and the clinical outcome of patients supported with ventricular assist devices (VADs) to determine the role of BNP as a predictor for cardiac recovery.

BACKGROUND

Ventricular unloading in patients with end-stage heart failure supported by VADs may lead to myocardial recovery. The BNP is produced in the myocardium in response to chronic volume overload, but the effects on it of ventricular unloading by VADs are largely unknown.

METHODS

Twenty-one patients diagnosed with nonischemic cardiomyopathy and supported by VADs were evaluated for echocardiographic data and blood chemistry including BNP. They were divided into patients who died while on mechanical support (group I; N = 9), patients who were transplanted (group II; N = 8) and patients who were successfully weaned off the system and did not require transplantation (group III; N = 4).

RESULTS

Brain natriuretic peptide plasma concentrations decreased significantly after initiation of mechanical circulatory support (p = 0.017). Furthermore, the changes in BNP plasma concentrations showed a faster decrease to normal levels within the first week after implantation of the VAD in patients who were weaned off the system (group III) compared to patients in group I and group II.

CONCLUSIONS

This study shows that ventricular unloading with VADs decreases BNP plasma concentrations in patients who suffer from end-stage heart failure. Furthermore, we hypothesize that an early decrease of BNP plasma concentration may be indicative of recovery of ventricular function during mechanical circulatory support.     

BNP-guided therapy not better than expert's clinical assessment for beta-blocker titration in patients with heart failure

B-type natriuretic peptide (BNP) is a cardiac neurohormone used as a noninvasive tool for diagnosing and monitoring heart failure. Beta blockers have beneficial effects in patients with heart failure as well as a direct effect on BNP plasma levels. The aim of this study is to compare the efficacy of a BNP-guided approach vs. standard care on beta-blocker titration in heart failure patients. Forty-one patients with heart failure were randomized into a clinical trial. Bisoprolol was started, and the dose was regularly up-titrated. BNP was measured monthly. The clinical group had beta-blocker dosage increased according to standard care, whereas the BNP group had beta-blocker dosage up-titrated according to plasma BNP levels plus standard care. The primary outcome was mean beta-blocker dose achieved after 3 months. BNP levels, left ventricular ejection fraction, clinical score, quality of life, and hospitalization were collected in all patients. BNP-guided up-titration of beta blocker in ambulatory patients with heart failure did not result in higher doses of beta blocker at the end of 3 months+/-SD (5.9+/-4.3 mg vs. 4.4+/-3.4 mg, p=0.22). Left ventricular ejection fraction was significantly improved in both groups by 7.3% (95% confidence interval, 4.1%-10.4%; p<0.0001). A trend toward better quality of life was seen in the BNP group.