High incidence of elevated B-type natriuretic peptide levels and risk factors for heart failure in an unselected at-risk population (stage A): implications for heart failure screening programs

Association of brain natriuretic peptide gene polymorphisms with chronic obstructive pulmonary disease complicated with pulmonary hypertension and its mechanism

Objective: To examine the association between brain natriuretic peptide (BNP) gene single nucleotide polymorphisms (SNPs) and chronic obstructive pulmonary disease (COPD) and COPD with pulmonary hypertension (PH) and to analyze its mechanism. Methods: The genotypes of BNP at the rs198389, rs6668352, and rs198388 loci in 339 patients with COPD (205 in the COPD/PH⁻ group and 134 in the COPD/PH⁺ group) and 125 healthy subjects were detected by PCR/Sanger sequencing. The serum levels of BNP, fibrinogen (Fbg), and Apelin were measured in all subjects by ELISA. Results: The BNP rs198389 locus G allele, rs6668352 locus A allele, and 198388 locus T allele were high risk factors for COPD (P<0.001). Logistics regression analysis showed that BNP rs198389 locus G allele, rs6668352 locus A allele, and rs198388 locus T allele were high risk factors for PH in COPD patients (all P<0.001). The levels of the serum BNP and Fbg protein in the control group, COPD/PH⁻ group, and COPD/PH⁺ group increased successively, and the expression levels of Apelin protein decreased successively (all P<0.001). The BNP and Fbg protein levels in the wild-type, heterozygote, and mutant homozygote in BNP rs198389, rs6668352, and rs198388 loci increased successively, and the serum Apelin protein levels decreased successively (all P<0.001). Conclusion: The polymorphisms of BNP at the rs198389, rs6668352, and rs198388 loci are associated with the occurrence of COPD and COPD with PH, and the occurrence may be related to the abnormal expression level of BNP, Fbg, and Apelin protein in the serum.

Exploratory analysis of cardiac biomarkers in women with normal cardiac function receiving trastuzumab for breast cancer

AIM

As there is no method to detect trastuzumab-related cardiotoxicity (TRC) preclinically, patients are monitored with serial assessments of left ventricular ejection fraction (LVEF) with instigation of cardiac therapy and possible interruption of trastuzumab therapy if TRC develops. Serum cardiac biomarkers, including troponins and natriuretic peptides, represent possible tools to detect cardiotoxicity at a preclinical level.

METHODS

We sought biochemical evidence of cardiac damage or strain in a cohort of women already receiving trastuzumab by performing a cross-sectional study of serum cardiac biomarkers. All patients had a normal LVEF and no clinical evidence of cardiac failure. Serum troponin I and N-terminal pro-B type natriuretic peptide (NT pro-BNP) were assayed immediately prior to trastuzumab infusion (t0; n = 36) and 24 hours later (t24; n = 31).

RESULTS

Troponin I was not elevated in any patient at t0 or t24. Overall 14/36 (39%) patients had at least one NT pro-BNP level above the upper limit of normal (ULN) and both levels were above the ULN in 8/31 (26%) patients. There was no significant change in NT pro-BNP from t0 to t24.

CONCLUSION

NT pro-BNP levels are elevated in a significant proportion of patients with normal LVEF receiving trastuzumab. Troponin I levels are not raised in this group, perhaps reflecting the mechanism of cardiotoxicity. The data provide biochemical evidence of subclinical cardiac strain in women receiving trastuzumab. Results are exploratory and have informed the design of a larger study examining the predictive utility of serial serum NT pro-BNP levels for TRC in the adjuvant setting.

Chronic heart failure: we are fighting the battle, but are we winning the war?

Heart failure represents an end-stage phenotype of a number of cardiovascular diseases and is generally associated with a poor prognosis. A number of organized battles fought over the last two to three decades have resulted in considerable advances in treatment including the use of drugs that interfere with neurohormonal activation and device-based therapies such as implantable cardioverter defibrillators and cardiac resynchronization therapy. Despite this, the prevalence of heart failure continues to rise related to both the aging population and better survival in patients with cardiovascular disease. Registries have identified treatment gaps and variation in the application of evidenced-based practice, including the use of echocardiography and prescribing of disease-modifying drugs. Quality initiatives often coupled with multidisciplinary, heart failure disease management promote self-care and minimize variation in the application of evidenced-based practice leading to better long-term clinical outcomes. However, to address the rising prevalence of heart failure and win the war, we must also turn our attention to disease prevention. A combined approach is required that includes public health measures applied at a population level and screening strategies to identify individuals at high risk of developing heart failure in the future.

[Validity and usefulness of B-type natriuretic peptide (BNP) for early detection of left ventricular dysfunction in high-risk patients in primary care]

OBJECTIVE

The aim of this study was to determine the accuracy of BNP test for early diagnosis of left ventricular dysfunction in patients at high-risk for heart failure.

DESIGN

Cross-sectional descriptive study.

SETTING

7 Primary Care Centres in Madrid (Spain).

PARTICIPANTS

A consecutive sample of 204 consecutive asymptomatic patients with high risk for heart failure (Stages A-B, AHA/ACC Classification).

MAIN MEASUREMENTS

BNP plasma levels were measured in the clinical setting using Triage BNP Test(®) (Biosite(®)) and an echocardiography was performed in the following 3 days in a single hospital unit as a reference standard. Plasma BNP levels were compared depending on the presence/absence of left ventricular dysfunction (LVD), type and severity degree. Sensitivity, specificity, positive and negative predictive values, and Área under the receiver operating characteristic curve (ROC) for BNP assay were calculated.

RESULTS

BNP values were significantly higher (P<.001) in patients with left ventricular systolic dysfunction (LVSD). No significant differences were found for diastolic dysfunction. The best cut-off value to discriminate the patients with LVSD was 71.00 pg/ml, with an Área under the ROC curve of 0.757 (95% CI 0.64-0.87). Sensitivity for LVD diagnosis was 75% (95% CI 50.66-99.34), specificity 70.19% (95% CI 62.81-77.57), positive predictive value (PPV) 20% (95% CI 9.05-30.95), and negative predictive value (NPV) 96.58% (95% CI 92.86-100), with LVSD prevalence of 9.04% in this population.

CONCLUSIONS

BNP determinations are of value in diagnosing LVSD in a primary care setting, with similar sensitivities and specificities. Due to the high NPV is useful to rule-out patients for echocardiography.

Growth differentiation factor 15 in different stages of heart failure: potential screening implications

Identification of individuals in the early stage of heart failure (HF) may allow earlier initiation of disease-modifying treatment. We evaluated concentrations of the growth differentiation factor (GDF)-15 at different stages and its potential screening value in 208 subjects. Plasma GDF-15 was measured by using an enzyme-linked immunosorbent assay. GDF-15 was positively correlated with the stages of HF (r=0.804, p<0.001). In distinguishing patients with stage B HF, the area under the curve was 0.873 (p<0.001). These findings indicate that GDF-15 concentration was elevated with the progressing stages of HF and might have potential screening implications for stage B HF.

Immunoreactivity and guanosine 3',5'-cyclic monophosphate activating actions of various molecular forms of human B-type natriuretic peptide

Recent studies support the speculation that different molecular forms of the cardiac hormone BNP with differential biological activity may circulate in heart failure and be detected by conventional assays. In the current study we determined the ability of 3 widely used conventional assays to detect these different forms thought to circulate in heart failure. We also evaluated the ability of pro-BNP (1-108), N-terminal peptide (NT)-pro-BNP (1-76), and BNP 3-32, the latter a cleavage product of BNP 1-32 by dipeptidyl peptidase IV, on an equimolar basis to activate cGMP in cultured cardiac fibroblasts and cardiomyocytes compared with the biologically active mature BNP 1-32. Specifically, we observed that the Roche NT-pro-BNP assay detected both NT-pro-BNP 1-76 and pro-BNP 1-108 and that Biosite Triage and Shionogi detected both mature BNP 1-32 and the shortened BNP 3-32. Moreover, in cultured cardiac fibroblasts and cardiomyocytes, BNP 1-32 (10(-6) mol/L) activated cGMP. BNP 3-32 demonstrated a similar cGMP activating property in both cardiac cell types. In contrast, the cGMP response to pro-BNP 1-108 and NT-pro-BNP 1-76 was not significantly greater than no treatment alone. We conclude that widely used commercial assays for NT-pro-BNP 1-76 and BNP 1-32 cannot differentiate among pro-, processed, or degraded forms and, thus, may not thoroughly identify circulating BNP forms in heart failure patients. These findings also demonstrate differential cGMP activating properties of BNP forms and, importantly, that pro-BNP 1-108 and NT-pro-BNP 1-76 have reduced cGMP activity in vitro that may have biological relevance to human heart failure.

Cost‐Effective Strategies to Screen for Left Ventricular Systolic Dysfunction in the Community—A Concept

Early detection of heart failure caused by left ventricular systolic dysfunction (LVSD) is important, since early treatment has been shown to retard the progression of heart failure. While traditional echocardiography remains the standard for the detection of LVSD, electrocardiography and serum brain natriuretic peptide have also been shown to predict LVSD. Recently, hand-held echocardiography systems have been shown to have high predictive accuracy for assessment of LVSD. With the availability of the above bedside and relatively less-costly techniques, compared with traditional echocardiography, the major question now is what is the most cost-effective strategy for screening subjects for LVSD. To date, no studies have systematically addressed this issue, but preliminary data are becoming available. This review article discusses the pros and cons of various investigative strategies and likely cost-effectiveness of each strategy to screen for LVSD.

Prospective screening for occult cardiomyopathy in dogs by measurement of plasma atrial natriuretic peptide, B-type natriuretic peptide, and cardiac troponin-I concentrations

OBJECTIVE

To evaluate the use of measuring plasma concentrations of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and cardiac troponin-I (cTnI) to detect dogs with occult dilated cardiomyopathy (DCM).

ANIMALS

118 client-owned dogs.

PROCEDURES

Dogs were prospectively examined by use of ECG; echocardiography; and evaluation of concentrations of ANP, BNP, and cTnI. Occult DCM was diagnosed by evaluation of echocardiographic left ventricular dimensions and detection of ventricular arrhythmias on ECG. Sensitivity and specificity of assays for measurement of plasma concentrations of ANP, BNP, and cTnI to detect dogs with occult DCM were determined.

RESULTS

Occult DCM was diagnosed in 21 dogs. A concentration of > 6.21 pg/mL for BNP had a sensitivity of 95.2% and specificity of 61.9% for identifying dogs with occult DCM. In contrast, concentrations of ANP and cTnI had relatively low predictive values.

CONCLUSIONS AND CLINICAL RELEVANCE

Blood-based screening for occult DCM in dogs can be accomplished by use of a BNP assay. Additional studies should be performed to optimize this method of screening dogs to detect occult DCM.

Impaired cardiac autonomic nervous activity predicts sudden cardiac death in patients with operated and unoperated congenital cardiac disease

OBJECTIVES

Sudden cardiac death is a leading cause of mortality in patients with congenital cardiac disease after surgical correction and is potentially preventable. The identification of patients at risk is therefore of major interest. We sought to assess the prognostic value of impaired cardiac autonomic nervous activity in patients with congenital cardiac disease.

METHODS

Forty-three consecutive patients with congenital cardiac disease were included in this prospective study. Parameters of heart rate turbulence and heart rate variability were calculated from Holter electrocardiograms. In addition, serum brain natriuretic peptide levels were measured. A combined end point of sudden cardiac death or nearly missed sudden cardiac death was used.

RESULTS

During a mean follow up of 27 +/- 12.7 months, 5 patients died, and another 2 were successfully resuscitated. On univariate analysis, both brain natriuretic peptide levels and parameters of heart rate variability and heart rate turbulence were associated with impaired prognosis. On multivariate analysis, pathologic heart rate turbulence was found to be the strongest independent risk stratifier (hazard ratio, 61.5; P < .001).

CONCLUSIONS

Impaired cardiac autonomic nervous activity is associated with an increased risk of sudden cardiac death in congenital cardiac disease. Our results suggest that heart rate turbulence might be superior to established markers of cardiac autonomic dysfunction, such as heart rate variability. The combined use of heart rate turbulence, heart rate variability, and markers of neurohormonal activation, such as brain natriuretic peptide, might further improve the prognostic value.

Amino-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide: biomarkers for mortality in a large community-based cohort free of heart failure

Recent studies report that, in the absence of heart failure and renal failure, plasma B-type natriuretic peptide (BNP) has prognostic value for mortality. We sought to confirm and extend these previous studies to assess BNP, measured by 3 distinct assays, as a biomarker for mortality in a strategy to enhance efforts at primary prevention and to better understand the clinical phenotype of such subjects at risk. We used a community-based cohort of 2042 subjects from Olmsted County, Minn, and individuals with heart or renal failure were excluded. BNP was assessed using 3 assays including Biosite and Shionogi for mature, biologically active BNP and the Roche assay for apparently nonbiologically active amino-terminal pro-BNP (NT-proBNP). Thorough echocardiographic and clinical data were recorded for all of the participants. Median follow-up for mortality was 5.6 years. BNP by all 3 of the assays was predictive of mortality. NT-proBNP and Biosite assays remained significant even after adjustment for traditional clinical risk factors and echocardiographic abnormalities including left ventricular hypertrophy and diastolic dysfunction. Echocardiography documented widespread structural changes in those with increasing BNP levels yet below levels observed in heart failure. We report in a large, well-characterized community-based cohort, free of heart failure, the first study to compare 3 distinct BNP assays as biomarkers for mortality in the same cohort. Our findings confirm the potential use of NT-proBNP and BNP biomarkers for future events and underscore that these peptides may also serve as biomarkers for underlying cardiac remodeling secondary to diverse cardiovascular disease entities.

Cardiac unilateral pulmonary edema: is it really a rare presentation?

Unilateral pulmonary edema is a distinctly unusual clinical entity that presents interesting and confusing diagnostic challenges. It is usually described as occurring with re-expansion of a collapsed lung after rapid thoracocentesis of pleural air or pleural fluid. Unilateral pulmonary edema as an initial presenting manifestation for heart failure is uncommon and can be confused with other more common causes of alveolar or interstitial infiltrate, which can lead to a significant delay in treatment.

BNP--Considering a heartfelt message

The natriuretic hormones have been discovered as mediators of the cardiac response to volume overload and mechanical dysfunction. Although there are some physiological differences between atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), it is BNP that has been found to be most useful as a clinical test. BNP is secreted along with an N terminal proBNP cleavage product (NT-proBNP). The similarities between these two tests are far greater than the differences. They are both probably useful in the diagnosis of high-risk patients (e.g. dyspnoeic) and may be useful in monitoring cardiac failure treatment. Although BNP levels in the normal range predict the risk of cardiac events and mortality, there is little evidence to promote their use as a screening test. In such an important condition as cardiac failure we should consider any messages that are likely to be of value, particularly those that are heartfelt.

B-type natriuretic peptide as a biomarker beyond heart failure: speculations and opportunities

Cardiac secretion of B-type natriuretic peptide (BNP) Increases with the progression of heart failure (HF), and plasma measurement of BNP has emerged recently as a useful, cost-effective biomarker for the diagnosis and prognosis of HF. The diagnostic utility of BNP is complemented by its therapeutic use in decompensated HF. Although clinical use of BNP as a biomarker in HF is Increasing, the specificity of BNP for HF is not robust, suggesting that other mechanisms beyond simple ventricular stretch stimulate BNP release. Several studies have shown that BNP levels Increase in other cardiovascular disease states including ischemia, arrhythmias, fibrosis, cardiac hypertrophy, and coronary endothelial dysfunction. Furthermore, 2 important studies revealed recently that moderate elevations In BNP level, well below the HF range, have prognostic value for future cardiovascular events. Specifically, BNP levels greater than 20 pg/mL were associated with significantly Increased risk of HF and atrial fibrillation. These observations increase speculation that elevated BNP levels represent a final common pathway for many cardiovascular pathologic states and that BNP can be used as a biomarker for non-HF mechanisms, preclinical disease, and other pathologic states of myocardial disease.

Functional Valvular Incompetence in Decompensated Heart Failure: Noninvasive Monitoring and Response to Medical Management

OBJECTIVE

We hypothesized that functional mitral and tricuspid valvular incompetence (MR and TR, respectively) are reversible causes of reduced cardiac output in decompensated heart failure (DF) that accompanies systolic dysfunction in ischemic or nonischemic cardiomyopathy.

BACKGROUND

DF, defined as signs and symptoms of heart failure at rest, is rooted in a salt-avid state transduced by neurohormonal activation secondary to impaired renal perfusion. Functional MR and TR are reversible causes of reduced systemic blood flow. Their impact on cardiac output, thoracic fluid content, cardiac chamber dimensions, and valvular apparatus function can be monitored noninvasively, before and after optimized medical management.

METHODS

Fourteen male subjects (66 +/- 8 years old) with reduced ejection fraction (24 +/- 5%) secondary to ischemic (71%) or nonischemic (29%) cardiomyopathy, who developed DF with clinical evidence of mitral (MR) and tricuspid (TR) valvular incompetence, were each assessed by bioimpedance and echocardiography before and 1 week after optimized medical management restored compensated failure.

RESULTS

Pharmacologic elimination of DF was accompanied by a reduction in body weight (P < 0.01). Hemodynamic improvements included a rise in cardiac index (2.1 to 2.6 L/min/m2; P < 0.01) and a reduction in predicted pulmonary artery systolic pressure (58 to 35 mm Hg; P < 0.001), thoracic fluid content (39 to 32 kOhm; P < 0.001), and systemic vascular resistance (1633 to 1209 dynes/sec/cm5; P < 0.001). Improvements in functional MR and TR included reductions in left and right atrial areas (27 to 24 cm and 26 to 23 cm2, respectively; P < 0.001), color-flow grading of MR and TR severity (P < 0.01), mitral regurgitant volume (105 to 65 mL; P < 0.001), and effective MR orifice size (0.8 to 0.6 cm2; P < 0.01).

CONCLUSIONS

In DF, functional MR and TR contribute to reduced cardiac output, increased thoracic fluid content, and systemic vascular resistance, together with enlarged atria and valvular orifice size, which can be improved by medical management. Bioimpedance and echocardiography provide for serial noninvasive assessments of hemodynamic status and valvular function in such cases.

BNP Consensus Panel 2004: A Clinical Approach for the Diagnostic, Prognostic, Screening, Treatment Monitoring, and Therapeutic Roles of Natriuretic Peptides in Cardiovascular Diseases

Among the most exciting developments in the field of heart failure in recent times has been the rediscovery of the natriuretic peptide system and its pleuripotent effects on cardiac structure and function. This is particularly true of its natriuretic and hemodynamic effects. There has been an explosion of the knowledge base seeking to understand the wide range of homeostatic, regulatory, and counter-regulatory functions in which the natriuretic peptide system participates. Additional interest has been stimulated by advances in technology such as point-of-care and core laboratory BNP assays and the use of the recombinant B-type natriuretic peptide nesiritide as a treatment option. Despite this recent interest, the available literature lacks a comprehensive expert review of the current science and roles of natriuretic peptides for diagnostic, prognostic, screening, treatment monitoring, and therapeutic purposes. More importantly, a summary updating and guiding the clinician on most of these advances was lacking. An expert Consensus Panel with basic, methodological, and clinical expertise was convened to summarize current knowledge in these areas and the findings and consensus statements are contained herein.

Plasma brain natriuretic peptide in obstructive sleep apnea

We compared brain natriuretic peptide (BNP) levels in patients with obstructive sleep apnea (OSA) with and without cardiovascular disease to BNP in healthy control subjects. OSA was not associated with increased plasma BNP or atrial natriuretic peptide (ANP) in otherwise healthy subjects during wakefulness. Untreated OSA increased ANP overnight, and ANP levels decreased with treatment of OSA. However, OSA did not elicit acute overnight changes in BNP, either in normal subjects or in patients with coexisting cardiovascular disease (including chronic heart failure).

B-type natriuretic peptide: practical diagnostic use for evaluating ventricular dysfunction

Assessment of brain natriuretic peptide levels may provide important information that can be used in the evaluation of patients with dyspnea and follow-up of heart failure. Brain natriuretic peptide levels have been shown to be useful for evaluating patients in the emergency department and for evaluating patients complaining of dyspnea in the outpatient setting. Brain natriuretic peptide assessment also provides an adjunct to diagnosis of both systolic and diastolic dysfunction, has prognostic value for heart failure and in acute coronary syndromes, and may be a useful measure to guide therapy. Further work needs to be done to establish the best type of assay to use, to determine the optimal cutoff point for what is considered abnormal, and to determine how conditions other than ventricular dysfunction affect brain natriuretic peptide levels.