B-type natriuretic peptide in predicting the severity of community-acquired pneumonia

BACKGROUND: Although pneumonia severity index(PSI) is widely used to evaluate the severity of community-acquired pneumonia(CAP), the calculation of PSI is very complicated. The present study aimed to evaluate the role of B-type natriuretic peptide(BNP) in predicting the severity of CAP.METHODS: For 202 patients with CAP admitted to the emergency department, BNP levels, cardiac load indexes, inf lammatory indexes including C-reactive protein(CRP), white blood cell count(WBC), and PSI were detected. The correlation between the indexes and PSI was investigated. BNP levels for survivor and non-survivor groups were compared, and a receiver operating characteristic(ROC) curve analysis was performed on the BNP levels versus PSI.RESULTS: The BNP levels increased with CAP severity(r=0.782, P0.001). The BNP levels of the high-risk group(PSI classes IV and V) were signifi cantly higher than those of the low-risk group(PSI classes I–III)(P0.001). The BNP levels were signifi cantly higher in the non-survivor group than in the survivor group(P0.001). In addition, there were positive correlations between BNP levels and PSI scores(r=0.782, P0.001). The BNP level was highly accurate in predicting the severity of CAP(AUC=0.952). The optimal cut-off point of BNP level for distinguishing high-risk patients from low-risk ones was 125.0 pg/m L, with a sensitivity of 0.891 and a specifi city of 0.946. Moreover, BNP level was accurate in predicting mortality(AUC=0.823). Its optimal cut-off point for predicting death was 299.0 pg/m L, with a sensitivity of 0.675 and a specifi city of 0.816. Its negative predictive cut-off value was 0.926, and the positive predictive cut-off value was 0.426.CONCLUSION: BNP level is positively correlated with the severity of CAP, and may be used as a biomarker for evaluating the severity of CAP.     

Usefulness of B-type natriuretic peptide in elderly patients with acute dyspnea

Objective Differentiating cardiogenic pulmonary edema (CPE) from respiratory causes of dyspnea is particularly difficult in elderly patients. The aim of our study was to evaluate B-type natriuretic peptide (BNP) in patients older than 65 years presenting with acute dyspnea.Design Prospective study.Setting Medical emergency department of a 2000-bed urban teaching hospital.Patients Patients aged over 65 years presenting with acute dyspnea and a respiratory rate more than 25/min or a PaO₂ below 70 mmHg, SpO₂ less than 92%, PaCO₂ higher than 45 mmHg with pH less than 7.35, were included. BNP levels, measured blind at admission were compared with the final diagnosis (CPE or no CPE) as defined by experts.Intervention None.Measurements and results Three hundred eight patients (mean age of 80 years) were enrolled in the study. The median BNP was 575 pg/ml [95% confidence interval (CI): 410–898] in the CPE group (n=141) versus 75 pg/ml (95% CI: 59–98) in the no CPE group (n=167) (p<0.001). The best threshold value of BNP was 250 pg/ml, with a sensitivity and specificity for CPE of 0.78 (95% CI: 0.71–0.84) and 0.90 (95% CI: 0.84–0.93), respectively. The area under the ROC curve was 0.874±0.081 (p<0.001). The accuracy of BNP-assisted diagnosis was higher than that of the emergency physician (0.84 versus 0.77, p<0.05).Conclusion Analysis of BNP is useful in elderly patients with acute dyspnea, but the threshold value is higher than that previously determined.Presented, in part, at the 30^th annual congress of the Société de Réanimation de Langue Française, Paris, January 2002 (abstract no. SP 94).     

B-type natriuretic peptide in pediatrics

OBJECTIVES: There has been growing interest in the use of serum B-type natriuretic peptide (BNP) and the N-terminal segment of its pro-hormone (NT-proBNP) as biomarkers for cardiac disease. The aim of this review is to summarize the current state of knowledge regarding BNP and NT-proBNP measurement in the pediatric population. DESIGN AND METHODS: A computerized literature search on the National Library of Medicine was done and all articles including BNP and pediatrics were selected and discussed. RESULTS: The data from several studies suggest that the measurement of BNP may be useful in diagnosing and managing pediatric heart failure, congenital heart disease, cardiac transplantation and patients on chemotherapy. There are difficulties in establishing appropriate reference ranges in children. CONCLUSION: There is insufficient evidence for the routine use of BNP or NT-proBNP. Further research to clearly define the clinical utility in the pediatric age group is eagerly anticipated.     

B型钠尿肽研究进展

B型钠尿肽 (BNP)作为一种主要由心室分泌的多肽类神经激素 ,在血容量稳定中起重要作用。血浆中的BNP水平在许多病理生理状态下均有所改变 ,尤以心力衰竭为甚。诸多研究表明 ,BNP在心力衰竭 (HF)、急性心肌梗死 (AMI)等心血管疾病的诊断及预后判断等方面有重要价值。由于BNP的测定简便易行 ,准确可靠 ,近年来在心血管疾病的诊疗中日益得到广泛应用。     

慢性心房颤动患者血浆脑钠肽水平相关因素分析

目的 探讨影响慢性心房颤动(CAF)患者血浆B型脑钠肽(BNP)水平的相关因素。方法 采用免疫荧光定量测定法检测222例CAF患者[按左心室射血分数(LVEF)高低分为LVEF≥50％组147例,与LVEF＜50％组75例的血浆BNP含量;采用多普勒超声心动图判断LVEF;同时测定患者血糖、总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、肌酐、尿素氮、肌酸;并记录患者的高血压病史、糖尿病病史、吸烟史。结果 BNP含量在LVEF＜ 50％组较≥50％组明显升高(平均秩,158.00和87.78,Z=-7.705,P＜0.001);Logistic回归分析提示:男性(OR 13.115,95％ CI 3.382 ～50.860,P＜0.001)、高血压病史(OR 3.710,95％ CI 1.104 ～ 12.472,P=0.034)、低总胆固醇(OR 0.397,95％ CI 0.214～0.735,P=0.003)、LVEF(OR 0.791,95％ CI 0.723 ～0.867,P＜0.001)、吸烟史(OR4.660,95％ CI 1.256 ～ 17.281,P=0.021)是BNP升高的独立危险因子。结论 在CAF患者中低左心室射血分数、男性、高血压史、低总胆固醇及吸烟史是血浆BNP水平升高的独立预测因子。     

检测B型利钠肽对急诊呼吸困难的鉴别诊断意义

目的:探讨B型利钠肽(B-type natriuretic peptide,BNP)用于甄别急诊呼吸困难中的充血性心力衰竭(congestive heart failure,CHF)的早期诊断意义.方法:130例急诊呼吸困难患者,根据临床资料及左心室射血分数(left ventricul ejection fraction,LVEF)分为CHF组(78例)和非CHF组(52例).采用干式快速免疫荧光法定量分析检测血液中的BNP浓度.结果:CHF组BNP浓度为(732±53)ng/L,显著高于非CHF组的(71±34)ng/L(P＜0.01);以BNP 100ng/L作为阈值区分呼吸困难是否为CHF所致,其敏感度、特异度、准确性分别为92%、96%、93%;在CHF组中,BNP浓度在不同心功能级别之间差异有统计学意义(P＜0.01),随心功能不全加重而升高.猝死者的BNP值高于存活者.结论:BNP水平对于CHF的诊断具有较高的灵敏度、特异度和准确性.对于鉴别呼吸困难是否为心源性具有重要意义.     

N末端B型钠尿肽原对充血性心力衰竭患者预后及危险分层评价的价值

目的通过对充血性心力衰竭（CHF，心衰）患者的随访研究，探寻影响心衰预后的因素，并对N末端B型钠尿肽原（NT-proBNP）对CHF患者预后及危险分层价值进行评价。方法对我院明确诊断为CHF的97例住院患者，测定入院时血清NT-proBNP、心肌肌钙蛋白T（cTnT）、心肌肌钙蛋白I（cTnI）、肌酸激酶MB型同工酶（CK-MB）以及纽约心脏病协会心功能分级（NYHA分级）和左室射血分数（LVEF）等指标。随访观察患者心脏事件的再发生。结果97例心衰患者，中位随访423d（43～505d），发生心脏事件23例（23．7％）。发生终点事件组与未发生终点事件组相比，患者的年龄（83比73，P=0．000）、NYHA分级（3比2，P=0．002）、NT-proBNP（973pg／ml比212．35pg／ml，P=0．002）、cTnT（0比0，P=0．011）以及cTnI（0．04比0．02，P=0．038）中位数水平均明显偏高。Cox比例风险模型分析显示，在包括了年龄、NYHA分级、LVEF、LogNT-proBNP、cTnT、cTnI及CK．MB等指标后，只有年龄和NT-proBNP是独立的心脏事件再发生的预后因素，OR分别为1．17和（95％CI：1．09～1．24，P〈0．1301）和3．17（95％CI：1．76～5．69，P〈0．001）。以NT-proBNP中位数水平302．1pg／ml对心衰患者进行危险分层，NT-proBNP〉302．1pg／ml的心衰患者，其心衰后心脏事件再发生的风险是NT-proBNP≤302．1pg／ml患者的4．63倍（95％CI：1．80～9．46，P=0．0008）。年龄〉74岁的心衰患者，其心脏事件再发生的风险是年龄≤74岁的心衰患者的5．40倍（95％CI：2．16～11．52，P=0．0002）。其他NYHA分级、LVEF、cTnT、cTnI及CK-MB等指标对心衰后心脏事件再发生均没有预后价值。结论NT-proBNP可以用于对心衰患者进行心衰后心脏事件再发生的预后分析及危险分层评估。     

B-type natriuretic peptide levels in patients with COPD and normal right ventricular function

INTRODUCTION: Evidence suggests that elevated plasma levels of B-type natriuretic peptide (BNP) are found in patients with chronic obstructive pulmonary disease (COPD) and right ventricular dysfunction. We examined the effects of exercise on plasma BNP levels in patients with COPD who have normal right ventricular function METHODS: Seventeen patients with a diagnosis of COPD and normal right ventricular function demonstrated by radionuclide ventriculography, and 17 age-and sex-matched healthy subjects underwent a treadmill exercise test. Plasma BNP levels were measured sequentially before, immediately after, and 1 hour after the exercise test RESULTS: The mean plasma BNP+/-standard deviation levels of the COPD and control groups before exercise were 21.3+/-16 pg/ml and 13.4+/-11 pg/ml, respectively (P>0.05). Mean plasma BNP level measured immediately after exercise was 37.9+/-31 pg/ml in the COPD group, reflecting a statistically significant increase when compared with the initial value (P<0.05). The control group did not show any significant change in plasma BNP levels after the exercise test CONCLUSIONS: Exercise induces an increase in plasma BNP levels in patients with COPD who do not have right ventricular dysfunction at rest. Measurement of exercise-induced BNP levels may be a useful alternative to pulmonary artery catheterisation in identifying the patients who are likely to benefit from long-term oxygen therapy.     

B-type natriuretic peptide in acute pulmonary embolism

Myocardial stretch leads to the natriuretic peptides release in acute or chronic left ventricular dysfunction. However, there is an accumulating evidence that B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) may originate from right ventricle and their concentrations are elevated in patients with acute pulmonary embolism (APE) especially when resulting in right ventricular dysfunction (RVD). Recently it is underlined that severity assessment of APE as well as the risk stratification and therapy selection is based both on patients' hemodynamic status and markers of myocardial injury and RVD. BNP and NT-proBNP are helpful in identifying patients with RVD in APE, emerging as an adjunctive tool to echocardiography. Elevated BNP or NT-proBNP levels are also significant predictors of death and/or complicated clinical course in APE.     

B型钠尿肽预测社区获得性肺炎严重程度的意义

目的 通过对社区获得性肺炎(community-acquired pneumonia,CAP)患者BNP(B型钠尿肽)与肺炎严重程度之间相关性的研究,评估BNP预测CAP严重程度的意义.方法 2011年12月至2012年12月就诊我科并确诊CAP患者202例,测定BNP、C-反应蛋白(CRP)、白细胞计数(WBC),以及肺炎严重度评分(PSI)所需相关指标,计算PSI评分并分级.分析不同肺炎严重程度分级之间BNP水平、C-反应蛋白、白细胞计数的差异,以及BNP与PSI的相关性.进一步根据PSI水平分为高风险组(PSI分级Ⅳ、Ⅴ级)和低风险组(PSI分级Ⅰ～Ⅲ级);根据患者预后分为存活组和死亡组.比较两组间BNP差异、BNP水平与肺炎严重程度的受试者工作特征(ROC)曲线.结果 BNP水平随着CAP严重程度增加而升高(r =0.782,P＜0.001);高风险组患者BNP水平显著高于低风险阻[(263.2±119.6)pg/mLvs.(71.5±54.3) pg/mL,P＜0.001].相比存活组,死亡组BNP水平更高[(343.86±125.49)vs.(183.00±121.71) pg/mL,P＜0.001].BNP与PSI评分、CRP以及WBC呈正相关(r=0.782,P＜0.001,r=0.560,P＜0.001和r=0.513,P＜0.001).BNP对于CAP严重程度的预测有较高的准确性(AUC =0.952),区分高、低风险的BNP最佳截点为125.0 pg/mL,敏感性0.891,特异性0.946.BNP能预测死亡(AUC =0.823),其预测死亡最佳截点为299.0 pg/mL,敏感性0.675,特异性0.816,阴性预测值0.926,阳性预测值0.426.结论 BNP与CAP严重程度呈正相关关系,BNP大于125.0 pg/mL的CAP患者建议住院治疗,BNP大于299.0 pg/mL的CAP患者具有死亡高风险.BNP预测CAP严重程度具有一定实用性.     

Determinants of markedly increased B-type natriuretic peptide in patients with ST-segment elevation myocardial infarction

Background

A modestly increased plasma B-type natriuretic peptide (BNP) level of greater than 80 pg/mL has been associated with increased mortality in patients with ST-segment elevation myocardial infarction (STEMI). However, the prognostic significance of larger increases in BNP during STEMI has not been reported.

Methods

A total of 420 patients with STEMI were identified from an administrative database, and 91 were found to have a BNP level measured within 24 hours of hospitalization. All patients underwent detailed angiographic and echocardiographic evaluation. Charts were abstracted in a blinded fashion to the BNP results.

Results

The mean ± SD age of the participants was 64 ± 13 years, and 53 (58%) of the participants were men. The median, 25th percentile, and 75th percentile of the BNP value were 366, 142, and 1011 pg/mL, respectively. The BNP level increased progressively in 1-, 2-, and 3-vessel coronary disease with medians of 253, 351, and 818 pg/mL, respectively (P = .009). Patients with grade 3/4 diastolic dysfunction had significantly increased median BNP values vs all others, 786 vs 306 pg/mL (P = .03). Eight (9%) patients died during their hospitalization. The median BNP values for 83 (91%) survivors and 8 (9%) nonsurvivors were 344 and 1420 pg/mL, respectively (P = .007). By multiple logistic regression, BNP level more than 500 pg/mL was independently associated with female sex, increased number of vessels diseased (>75% stenosis), lower ejection fraction, higher creatine kinase level, and lower body mass index.

Conclusion

In patients with STEMI, markedly increased BNP level seems to reflect the extent of coronary disease, the degree of associated systolic and diastolic dysfunction, and a higher risk of in-hospital mortality.     

Head to head comparison of N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide in patients with/without left ventricular systolic dysfunction

BACKGROUND: Human pro-B-type natriuretic peptide is cleaved into the active B-type natriuretic peptide (BNP) and the inactive fragment NT-proBNP. It is unclear if, similar to BNP, NT-proBNP can be used as a marker of impaired left ventricular (LV) ejection fraction (EF). This study evaluated the analytical performance of both assays to detect LV systolic dysfunction. METHODS: In 72 patients with various degrees of left ventricular systolic dysfunction (LVSD), blood analysis for BNP and NT-proBNP was performed prior to cardiac catheterization, using a point-of-care analyzer (Biosite) and a fully automated laboratory analyzer (Roche-Elecsys), respectively. The within-run and between-run imprecision for BNP and NT-proBNP was calculated. RESULTS: Both markers were able to detect impaired LV EF with the largest area under the receiver-operating-characteristic curve for NT-proBNP (NT-proBNP: 0.851 (0.747-0.924); BNP: 0.803 (0.692-0.887) 95% confidence interval; P = 0.07). A significant correlation was observed between BNP and NT-proBNP (r = 0.9; P < 0.0001). Estimating the within-run imprecision, the coefficient of variance for BNP was 3.14% (n = 20, mean 316 ng/L) to 3.32% (n = 20, mean 820 ng/L) and for NT-proBNP 0.9% (n = 20, mean 4390.8 ng/L) to 1.4% (n = 20, mean 225 ng/L). The between-run imprecision for NT-proBNP ranged between 2.1% (n = 20, mean 224.6 ng/L) and 2% (n = 20, mean 4391 ng/L). Optimal discriminator values for BNP and NT-proBNP were 139 ng/L and 358 ng/L, respectively. However, adjusting the BNP cut-off value to 54 ng/L improved the negative predictive value and sensitivity of the assay. CONCLUSION: Similar to BNP, NT-proBNP is a promising marker in identifying LVSD. Although both assays are reliable and have good analytical performance, their diagnostic cut-off value is dynamic and population-dependent. The slightly wider detection range and the more stable structure of NT-proBNP compared to the BNP assay suggest that NT-proBNP could play an additional role in the evaluation of patients with LV systolic dysfunction.     

Quality specifications for B-type natriuretic peptide assays

BACKGROUND: The objective of this report is to improve the quality of immunochemical measurements of B-type natriuretic peptide (BNP) and its N-terminal propeptide (NT-proBNP). The recommendations proposed are intended for use by manufacturers of commercial assays, by clinical laboratories using those assays, by clinical trial groups and research investigators, and by regulatory agencies, such as the United States Food and Drug Administration. METHODS: A group of cardiac biomarker experts reviewed and abstracted the scientific literature to provide recommendations pertaining to the quality specifications for BNP/NT-proBNP assays. RESULTS: The evidence-based recommendations encourage manufacturers to endorse and consistently follow the proposed recommendations; encourage that all package inserts for BNP/NT-proBNP immunoassays include uniform information on assay design, preanalytical performance characteristics, analytical performance characteristics, and clinical performance; and encourage regulatory agencies to adopt a minimal and uniform set of criteria for manufacturers to provide when seeking clearance for new and/or improved assays. CONCLUSIONS: These recommendations address the use of BNP and NT-proBNP as cardiac biomarkers and not their physiologic and/or pathophysiologic relevance.     

Correlation between impedance cardiography and B-type natriuretic peptide levels in dyspneic patients

Background: Both serum measurements of B-type natriuretic peptide (BNP) and impedance cardiography (ICG) are used to evaluate patients for congestive heart failure (CHF) in the Emergency Department (ED), but the agreement between the data obtained by these two methods remains uncertain. Study Objectives: We sought to measure the correlation between BNP levels and ICG measurements in patients presenting to the ED with dyspnea, and compare the diagnostic accuracy of each method in diagnosing CHF. Methods: We performed a prospective observational study of a convenience sample of patients presenting to the ED with dyspnea and being evaluated for CHF as a cause of their symptoms. An ICG measurement was obtained on each patient and the correlation between BNP level and the ICG parameters cardiac index (CI), systemic vascular resistance (SVR), and thoracic fluid content (TFC) was measured. To further quantify the diagnostic accuracy of ICG and BNP, we then constructed receiver operating characteristic curves based on discharge diagnosis of CHF and compared the area under the curve (AUC) of each test. Results: Out of 54 patients enrolled, correlation was poor between BNP and CI (Spearman's ρ = −.07, p = 0.64) and between BNP and SVR (Spearman's ρ = −.10, p = 0.46), but moderate between BNP and TFC (Spearman's ρ = .32, p = 0.02); a wide degree of scatter was seen in all correlations. BNP levels showed the best diagnostic accuracy for a discharge diagnosis of CHF, with an AUC of .77 (95% confidence interval .59–.95), whereas CI had an AUC of .72 (95% confidence interval .55–.88). Conclusion: We found limited correlation between BNP levels and ICG parameters, suggesting that, in our population, the two tests may not consistently give similar information. BNP level and CI both provided only fair diagnostic accuracy for discharge diagnosis of CHF.     

B型钠尿肽对急性呼吸困难病因诊断的临床意义

目的 探讨B型钠尿肽(BNP)对鉴别急性呼吸困难病因的临床意义.方法 213例急性呼吸困难患者行BNP检测,将患者分为心源性急性呼吸困难组(112例)和肺源性急性呼吸困难组(101例),分别比较心源性和肺源性呼吸困难组不同心功能分级(NYHA)之间BNP水平、左室射血分数(LVEF)、左室舒张末期内径(LVEDD)及超敏C反应蛋白(hs-CRP)水平,计算BNP诊断心源性呼吸困难的受试者工作特征(ROC)曲线下面积及最佳界值.结果 心源性呼吸困难组BNP较肺源性组明显升高(P＜0.001),LVEDD也明显高于肺源性组＜0.001),但LVEF明显低于肺源性组(P＜0.001);不同心功能分级亚组之间BNP比较差异有统计学意义(P＜0.01);BNP及hs-CRP与LVEDD呈正相关;心源性呼吸困难患者BNP与LVEF呈高度负相关(r=-0.838,P＜0.001);BNP诊断心源性呼吸困难的ROC曲线下面积为0.926,95%可信区间为0.892～0.960(P＜0.01).BNP鉴别诊断的最佳界值为250 pg/mL,准确性为86%.结论 急性呼吸困难患者BNP的测定有助于心源性或肺源性病因的判定.     

Medical and economic long-term effects of B-type natriuretic peptide testing in patients with acute dyspnea

BACKGROUND: The objective of this prospective study was to assess the medical and economic long-term effects of using B-type natriuretic peptide (BNP) concentrations in the management of patients with acute dyspnea. METHODS: We performed follow-up analysis of the B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation, a randomized study including 452 patients who presented to the emergency department with acute dyspnea. Participants were randomly assigned to a diagnostic strategy involving the rapid measurement of BNP concentrations (n = 225) or standard assessment (n = 227). Mortality was assessed at 720 days, morbidity and economic data at 360 days. RESULTS: BNP testing induced several important changes in initial patient management, including a reduction in the initial hospital admission rate, the use of intensive care, and initial time to discharge. At 720 days, 172 deaths had occurred. Cumulative all-cause 720-day mortality was not different between the BNP group (37%) and the control group (36%, P = 0.6). Morbidity as reflected by days spent in-hospital at 360 days was significantly lower in the BNP group [median 12 days ([interquartile range 2-28 days)] compared with the control group [median 16 (7-32)] days, P = 0.025]. Functional status was similar in both groups. Economic outcome as quantified by total treatment cost at 360 days was significantly improved in the BNP group (mean 10,144 dollars vs 12,748 dollars in the control group, P = 0.008). CONCLUSIONS: Rapid BNP testing in patients with acute dyspnea has no effect on long-term mortality. However, morbidity as quantified by days spent in-hospital and economic outcome are still improved at 360 days.     

Elevated B-type natriuretic peptide levels in patients with nonischemic cardiomyopathy predict occurrence of arrhythmic events

BACKGROUND: Patients with nonischemic cardiomyopathy (DCM) are at high risk for sudden cardiac death (SCD). However, the predictive value of prophylactic implantation of implantable cardioverter defibrillators (ICD) in this patient cohort is yet unclear. METHODS AND RESULTS: Whether NT pro BNP levels and/or reproducible non sustained ventricular tachycardias (NSVTs) are predictive for SCD was prospectively tested in 30 patients with DCM and LVEF 相似文献