Interpretation of B-type natriuretic peptide in cardiac disease and other comorbid conditions

B-Type natriuretic peptide (BNP) is elevated in states of increased ventricular wall stress. BNP is most commonly used to rule out congestive heart failure (CHF) in dyspneic patients. BNP levels are influenced by age, gender and, to a surprisingly large extent, by body mass index (BMI). In addition, it can be elevated in a wide variety of clinical settings with or without CHF. BNP is elevated in other cardiac disease states such as the acute coronary syndromes, diastolic dysfunction, atrial fibrillation (AF), amyloidosis, restrictive cardiomyopathy (RCM), and valvular heart disease. BNP is elevated in non-cardiac diseases such as pulmonary hypertension, chronic obstructive pulmonary disease, pulmonary embolism, and renal failure. BNP is also elevated in the setting of critical illness such as in acute decompensated CHF (ADHF) and sepsis. This variation across clinical settings has significant implications given the increasing frequency with which BNP testing is being performed. It is important for clinicians to understand how to appropriately interpret BNP in light of the comorbidities of individual patients to maximize its clinical utility. We will review the molecular biology and physiology of natriuretic peptides as well as the relevant literature on the utilization of BNP in CHF as well as in other important clinical situations, conditions that are commonly associated with CHF and or dyspnea.     

Prognostic value of sequential measurements of amino-terminal prohormone of B-type natriuretic peptide in ambulatory heart failure patients

BACKGROUND: We evaluated the prognostic value of sequential NT-proBNP values in ambulatory heart failure patients after discharge, investigating whether the current value or the recent percent change is more important. METHODS AND RESULTS: In 166 patients, NT-proBNP was measured at discharge from heart failure hospitalisation and three months later. The combined endpoint of death or heart failure rehospitalisation was evaluated after a maximum of 18 months or at follow-up closure. During a mean observation time of 14+/-4 months, 63 patients (38%) reached the endpoint. In multiple Cox analysis, NT-proBNP three months after discharge (NT-proBNP-3Mo) and NT-proBNP percent change (NT-proBNP-%change) were the only independent predictors of the endpoint among various clinical and laboratory variables. After definition of a high- (n=83, 57% endpoints) and a low-NT-proBNP patient subgroup (n=83, 19% endpoints) according to the median NT-proBNP-3Mo (1751 pg/ml), NT-proBNP-%change was the strongest predictor in the high-NT-proBNP subgroup. In the low-NT-proBNP subgroup, NT-proBNP-3Mo was the only independent predictor. CONCLUSIONS: In ambulatory heart failure patients, the prognostic value of sequential NT-proBNP measurements depends on the magnitude of the current NT-proBNP value. Recent percent changes in NT-proBNP provide important prognostic information in patients with high NT-proBNP but not in patients with low NT-proBNP.     

B型利钠肽与慢性心力衰竭短期预后的关系

目的探讨B型利钠肽(BNP)能否反映慢性心力衰竭患者心功能的变化,以及比较它与生存质量、白介素-6(IL-6)、肌钙蛋白I(cTnI)对慢性心衰患者短期预后的影响。方法从2002年9月至2003年3月所有入住中山大学附属一院心血管内科的慢性心衰NYHA分级II—Ⅳ的患者共96例。入院第2天抽血检查BNP、IL-6、cTnI,入院1天内自行填写明苏达慢性心功能不全患者生存质量量表。3个月后重复测量BNP的水平并再次填写生存质量量表。结果BNP随着慢性心衰的严重程度升高而升高。躯体方面及总的生存质量得分都与慢性心衰的严重程度相关(P<0.05)。3个月后,好转的患者BNP水平下降了(P<0.05),恶化的患者BNP水平升高了(P<0.05)。以150ng/L为分割点用Kaplan-meier的方法分析得出高水平BNP患者的生存曲线明显高于低水平BNP的患者(P<0.01)。在单因素的logistic回归分析中纽约心功能分级、BNP、左室射血分数、左室舒张末直径、心脏增大、IL-6、生存质量总得分、躯体方面得分及精神方面得分都是有意义的短期预后因子,而在多因素回归分析中,只有BNP及生存质量精神方面得分是独立的短期预后因子。结论BNP水平的变化能反映慢性心衰的治疗效果。BNP及生存质量是慢性心衰两个主要的短期预后因子。     

Atrial secretion of B-type natriuretic peptide.

In the normal heart, the endocrine capacity resides in the atria. Atrial myocytes express and secrete natriuretic hormones that regulate fluid homeostasis and blood pressure. But in ventricular disease, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) gene expression is also activated in ventricular myocytes. Plasma concentrations of natriuretic peptides and their biosynthetic precursors are accordingly increased in patients with marked ventricular dysfunction. In contrast, atrial peptide secretion in ventricular disease has received less attention, and our present understanding of the endocrine atria during ventricular dysfunction is still scarce. Although ventricular disease and increased circulating concentrations are associated, it does not entail that the ventricle is the sole or even the main source in all types of heart disease. Clearly, the endocrine atria are also active in heart failure. Plasma measurement of cardiac natriuretic peptides and their molecular precursors can perhaps help us to discriminate when, where and how.     

B型钠尿肽在心血管系统疾病中的研究进展

钠尿肽包括A型钠尿肽（ANP）、B型钠尿肽（B—type natriuretie peptide,BNP）、C型钠尿肽和D型纳尿肽。其中BNP在临床中应用最多、最广泛,同时又称为脑钠肽（brain natriuretie peptide,BNP）。ANP是从大鼠心房组织中发现的一种具有利尿、利钠和扩血管作用的生物活性物质,     

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。     

B-type natriuretic peptide may predict prognosis in older adults admitted with a diagnosis other than heart failure

Background and Aims

The diagnosis of heart failure (HF) in elderly patients is often difficult, due to overlap of typical signs and symptoms with those of comorbidities. B-type Natriuretic Peptide (BNP) predicts diagnosis and prognosis of HF, but little is known on its predictive role of short-term prognosis when admission diagnosis is other than HF.

B型利钠肽和肺毛细血管嵌压对心力衰竭远期心脏事件的预测价值

目的 研究血浆B型利钠肽(BNP)和肺毛细血管嵌压(PCWP)对慢性心力衰竭(心衰)患者远期心脏事件的预测价值.方法 入选134例心衰患者,经Swan-Ganz导管测定PCWP,双抗体夹心免疫荧光法测定血浆BNP浓度.随访3年,记录发生的心脏事件.结果 (1)心脏事件组的心胸比率、PCWP、BNP较非心脏事件组显著升高(P<0.01).(2)多元Logisac回归分析PCWP和BNP为心衰患者远期心脏事件独立的预测因子.(3)BNP、PCWP预测心原性死亡ROC曲线下面积分别为0.846和0.762.BNP取值720.5 ng/L、PCWP取值19.5 mm Hg(1 mm Hg=0.133 kPa)预测心原性死亡的敏感度和特异度达最高.(4)血浆BNP≤702.5 ng/L组心衰患者的生存率高于BNP>702.5 ng/L组,PCWP≤19.5 mm Hg组心衰患者的生存率高于PCWP>19.5 mm Hg组;Log-Rank检验说明,不同PCWP和BNP两组生存时间之间差异有统计学意义(P<0.05).结论 BNP和PCWP是影响慢性心衰患者远期心脏事件的独立预测因素.     

B-型脑钠肽在慢性心衰治疗中的监测价值

目的研究血浆B-型脑钠肽(BNP)水平值在慢性心衰患者临床诊疗中的监测价值。方法选取153例慢性心衰患者分为慢性心衰组(91例)和非心衰组(62例),采取荧光酶标记的免疫学方法,检测两组受检者血浆BNP值并比较。结果慢性心衰组患者血浆中的BNP值含量明显高于非心衰组,并且BNP含量与心功能不全(CHF)的程度呈正相关性,BNP含量越高,CHF越严重。讨论揭示患者处于不同心衰阶段相对应的标准BNP值,该标准对慢性心衰患者的诊疗有一定的指导作用,并且检测血浆BNP含量的方法操作简单,特异性强,灵敏度高。     

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.     

BNP对稳定型冠状动脉疾病预后的判断价值

目的：探讨BNP对稳定型冠状动脉疾病患者的预后判断价值。方法：对186例稳定型冠状动脉疾病患者入院时测定其BNP值,并行冠状动脉及左室造影,平均随访16个月,观察其死亡率,对BNP与死亡率相关性进行统计学分析。结果：随访期间15例(8．0%)死亡。存活者的BNP均值显著低于死亡者(120pg/ml对386 pg/ml,P＜0．01)。BNP水平位于最高的四分位数的患者与低四分位数的患者相比,具有高龄、低左室射血分数(LVEF)等特点,更可能患有心肌梗死及糖尿病等病史。在多变量COX回归模型中,BNP水平位于第四个四分位数的患者与第一个四分位数相比,其死亡的危险比为2．4(95%CI：1．5～4．0,P＜0．001)。结论：BNP是稳定型冠状动脉疾病患者预后不良的指标,其预后判断价值可能大于常规的危险因素。     

Incremental prognostic value of changes in B-type natriuretic peptide in heart failure

Purpose

B-type natriuretic peptide is one of the most sensitive and specific biohumoral markers of heart failure. We hypothesized that B-type natriuretic peptide changes during treatment of heart failure may provide independent information on disease progression and outcome in patients enrolled in the Val-HeFT trial.

Methods

Patients were divided into four groups according to concentrations of B-type natriuretic peptide at baseline versus 4 months (n = 3740) or 12 months (n = 3343), with respect to the baseline median (97 pg/mL): low→low (stable below median, 44%-46%), high→high (stable above median, 32%-37%), high→low (above to below median, 12%-14%), and low→high (below to above median, 6%-9%). Cox multivariate regression analysis was used to assess the risk of death and morbidity, with adjustment for baseline B-type natriuretic peptide concentrations.

Results

Patients who improved their B-type natriuretic peptide at 4 months (high→low) had a similar risk for mortality (hazard ratio = 1.191, 95% confidence interval [CI] 0.870-1.631, P =.2746) compared with the low→low patients. Conversely, patients who worsened in their B-type natriuretic peptide (low→high) had a risk for mortality (hazard ratio 2.578, CI, 1.861-3.571, P <.0001) higher than patients in the low→low group, and indistinguishable from the high→high group. Worsening of B-type natriuretic peptide (low→high) was associated with 0.03 cm/m² increase in left ventricular end-diastolic diameter, whereas it decreased by 0.10 cm/m² in high→low and low→low groups (P <.001).

Conclusions

Changes in B-type natriuretic peptide over time with respect to a threshold value of 97 pg/mL convey an independent and additional prognostic value compared with a single determination of B-type natriuretic peptide in a large population of patients with chronic symptomatic heart failure and might be helpful in the management of these patients.     

脑钠肽对心力衰竭患者发生心房颤动的预测价值

目的通过测定心力衰竭(心衰)患者的血清脑钠肽(BNP)浓度,探讨BNP对心衰患者并发心房颤动(房颤)的预测价值。方法入选2010年7月至2013年12月在河南省安阳地区医院心内二科住院的心衰患者169例,152例完成随访,失访17例,其中男性79例,女性73例,年龄37~71岁,平均年龄(48±11)岁,根据随访结果将患者分为两组,房颤组(n=29)和窦性心律组(n=123)。所有患者在入选前以及随访1年均行Holter检查,同时检测患者血清BNP水平。结果随访1年后,152例患者完成随访,其中有29例患者记录到房颤。房颤组[(312.21±52.78)pg/ml]BNP水平明显高于窦性心律组[(218.24±67.45)pg/ml],差异具有统计学意义(P0.01)。多因素分析结果显示,年龄OR值为4.162,95%CI:1.521-7.132;LVEF OR值为1.027,95%CI:0.939-1.058。年龄和左室射血分数(LVEF)是心衰患者并发房颤的独立危险因素。结论血清BNP水平对心衰患者是否发生房颤有重要的预测价值。     

血浆N-末端脑利钠肽对急性呼吸困难诊断的临床意义

目的探讨血浆N-末端脑利钠肽(NT-proBNP)变化在急性心源性与非心源性呼吸困难患者中诊断和鉴别诊断的临床意义。方法选取2005年10月至2006年6月卫生部北京医院急诊科以呼吸困难为主诉就诊的患者93例,分为心源性呼吸困难组61例,非心源性呼吸困难组32例。其中心源性呼吸困难组按照超声心动图检查结果分为单纯舒张功能不全组25例,单纯收缩功能不全组21例,收缩并舒张功能不全组15例;同时按照纽约心功能分级标准(NYHA)对心功能进行分级。采用酶联免疫吸附法测定各组患者血浆NT-proBNP,用SPSS12.0软件对各组资料进行分析。结果心源性与非心源性呼吸困难组NT-proBNP分别为(3.591±2.943)μg/L和(0.429±0.119)μg/L,差异有显著性意义(P<0.01);心源性呼吸困难组中单纯舒张功能不全、单纯收缩功能不全与收缩合并舒张功能不全患者NT-proBNP为(2.328±1.366)μg/L、(3.966±2.714)μg/L、(5.172±4.203)μg/L,3组间差异有显著性意义(P<0.05);不同NYHA心功能亚组间NT-proBNP差异有显著性(P<0.05);心源性呼吸困难组血浆NT-proBNP与左心室射血分数之间呈中度负相关性(r=-0.599,P<0.01);但与左心室舒张末期内径间无关联(r=0.222,P<0.05)。结论血浆NT-proBNP对心源性呼吸困难和非心源性呼吸困难的诊断和鉴别诊断有实际意义。     

N末端B型利钠肽原在急诊老年呼吸困难患者鉴别中的应用意义

目的 研究血浆N末端B型利钠肽原(NT-proBNP)水平对急诊老年呼吸困难患者鉴别诊断的临床意义.方法 急诊科就诊老年呼吸困难患者182例,分为心源性呼吸困难和肺源性呼吸困难两组.分别检查血浆NT-proBNP含量,并给予心脏超声检查,比较两组患者NT-proBNP含量和左室射血分数的区别;并对心源性呼吸困难组NT-proBNP含量与左室射血分数进行相关分析.结果 肺源性呼吸困难组NT-proBNP含量为108.5±25.7 pg/ml,心源性呼吸困难组NT-proBNP含量为945.1±143.8 pg/ml(P=0.001);相关分析显示老年心源性呼吸困难组NT-proBNP与左室射血分数呈负相关关系(r=-0.62,P<0.01).结论 NT-proBNP对老年呼吸困难患者鉴别诊断具有一定临床意义.