Retrospective analysis of the cost-effectiveness of using plasma brain natriuretic peptide in screening for left ventricular systolic dysfunction in the general population

Artificial intelligence enabled ECG screening for left ventricular systolic dysfunction: a systematic review

Screening for left ventricular systolic dysfunction (LVSD), defined as reduced left ventricular ejection fraction (LVEF), deserves renewed interest as the medical treatment for the prevention and progression of heart failure improves. We aimed to review the updated literature to outline the potential and caveats of using artificial intelligence-enabled electrocardiography (AIeECG) as an opportunistic screening tool for LVSD.We searched PubMed and Cochrane for variations of the terms "ECG," "Heart Failure," "systolic dysfunction," and "Artificial Intelligence" from January 2010 to April 2022 and selected studies that reported the diagnostic accuracy and confounders of using AIeECG to detect LVSD.Out of 40 articles, we identified 15 relevant studies; eleven retrospective cohorts, three prospective cohorts, and one case series. Although various LVEF thresholds were used, AIeECG detected LVSD with a median AUC of 0.90 (IQR from 0.85 to 0.95), a sensitivity of 83.3% (IQR from 73 to 86.9%) and a specificity of 87% (IQR from 84.5 to 90.9%). AIeECG algorithms succeeded across a wide range of sex, age, and comorbidity and seemed especially useful in non-cardiology settings and when combined with natriuretic peptide testing. Furthermore, a false-positive AIeECG indicated a future development of LVSD. No studies investigated the effect on treatment or patient outcomes.This systematic review corroborates the arrival of a new generic biomarker, AIeECG, to improve the detection of LVSD. AIeECG, in addition to natriuretic peptides and echocardiograms, will improve screening for LVSD, but prospective randomized implementation trials with added therapy are needed to show cost-effectiveness and clinical significance.

Elevated NT-ProBNP as a Cardiovascular Disease Risk Equivalent: Evidence from the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

It remains unclear whether elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) can serve as a "risk equivalent" for cardiovascular disease to adults at high cardiovascular risk.

METHODS

We included 9789 participants (mean age 63.2 years, 55% women, 19.4% Black, 13% with a history of cardiovascular disease) who attended Atherosclerosis Risk in Communities Study Visit 4 (1996-1998). We classified participants as having a history of cardiovascular disease at baseline and, among those without cardiovascular disease, we defined categories of NT-proBNP (<125, 125-449, ≥450 pg/mL). We used Cox regression to estimate associations of NT-proBNP with incident cardiovascular disease and mortality.

RESULTS

Over a median 20.5 years of follow-up, there were 4562 deaths (917 cardiovascular deaths). There were 2817 first events and 806 recurrent events (in those with a history of cardiovascular disease at baseline). Among individuals without a history of cardiovascular disease, those adults with NT-proBNP ≥450 pg/mL had significantly higher risks of all-cause death (hazard ratio [HR] 2.12; 95% confidence interval [CI], 1.78-2.53), cardiovascular mortality (HR 2.92; 95% CI, 2.15-3.97), incident total cardiovascular disease (HR 2.59; 95% CI, 2.13-3.16), atherosclerotic cardiovascular disease (HR 2.20; 95% CI, 1.72-2.80), and heart failure (HR 3.81; 95% CI, 3.01-4.81), compared with individuals with NT-proBNP <125 pg/mL. The elevated cardiovascular risk in persons with high NT-proBNP and no history of cardiovascular disease was similar to, or higher than, the risk conferred by a history of cardiovascular disease.

CONCLUSIONS

Our findings suggest that it might be appropriate to manage adults with NT-proBNP ≥450 pg/mL as if they had a history of clinical cardiovascular disease.

Prognostic Role of B-Type Natriuretic Peptide in Adults with Acute Dyspnea Requiring Emergency Admission

Objective:

The aim of the study was to evaluate the role of B-type natriuretic peptide (BNP) in patients presenting with acute dyspnea admitted in emergency services.

Materials and Methods:

A prospective observational study was conducted on 100 patients presenting to the emergency of Dayanand Medical College and Hospital and Hero DMC Heart Institute with acute dyspnea of <48 h duration, in which BNP levels were done on arrival to emergency.

Results:

BNP levels were significantly higher in patients having left ventricular dysfunction, both systolic and diastolic. Patients with systolic dysfunction had slightly higher BNP (1251.50 ±950.14 pg/mL) compared to patients with diastolic dysfunction (905.62±618.10 pg/mL) though statistically insignificant (P = 0.055). BNP levels were also inversely related to ejection fraction. Mean BNP levels in patients with EF <31%, 31%–45%, 46%–59%, and ≥60% were 1464.63 ± 1058.29, 968.24 ± 751.59, 841.64 ± 503.41 and 781.67 ± 504.21 (P = 0.009), respectively. Patients having higher BNP levels had significantly prolonged duration of stay compared to patients with lower BNP. Patients who expired had slightly higher levels of BNP though statistically nonsignificant. BNP had no significant statistical relation with age, heart rate, creatine phosphokinase-MB, Trop-T levels, systolic blood pressure.

Conclusion:

We conclude that high BNP levels are a marker of cardiac dysfunction and increased duration of hospital stay in patients presenting to the emergency with acute dyspnea. Hence, BNP can be used as a screening test for the evaluation and management of dyspnea.

The therapeutic effect of B-type natriuretic peptides in acute decompensated heart failure

B-type natriuretic peptide (BNP) exhibits roles in natriuresis and diuresis, making it an ideal drug that may aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these have demonstrated beneficial outcomes. The current challenge for BNP research in acute HF lies in addressing a failure of concept and a reluctance to abandon an ineffective research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP, as well as better integration of basic and clinical science.

Natriuretic peptide-guided treatment for the prevention of cardiovascular events in patients without heart failure

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. Early intervention for those with high cardiovascular risk is crucial in improving patient outcomes. Traditional prevention strategies for CVD have focused on conventional risk factors, such as overweight, dyslipidaemia, diabetes, and hypertension, which may reflect the potential for cardiovascular insult. Natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro B-type natriuretic peptide (NT-proBNP), are well-established biomarkers for the detection and diagnostic evaluation of heart failure. They are of interest for CVD prevention because they are secreted by the heart as a protective response to cardiovascular stress, strain, and damage. Therefore, measuring NP levels in patients without heart failure may be valuable for risk stratification, to identify those at highest risk of CVD who would benefit most from intensive risk reduction measures.

OBJECTIVES

To assess the effects of natriuretic peptide (NP)-guided treatment for people with cardiovascular risk factors and without heart failure.

SEARCH METHODS

Searches of the following bibliographic databases were conducted up to 9 July 2019: CENTRAL, MEDLINE, Embase, and Web of Science. Three clinical trial registries were also searched in July 2019.

SELECTION CRITERIA

We included randomised controlled trials enrolling adults with one or more cardiovascular risk factors and without heart failure, which compared NP-based screening and subsequent NP-guided treatment versus standard care in all settings (i.e. community, hospital).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts and selected studies for inclusion, extracted data, and evaluated risk of bias. Risk ratios (RRs) were calculated for dichotomous data, and mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous data. We contacted trial authors to obtain missing data and to verify crucial study characteristics. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, two review authors independently assessed the quality of the evidence and GRADE profiler (GRADEPRO) was used to import data from Review Manager to create a 'Summary of findings' table.

MAIN RESULTS

We included two randomised controlled trials (three reports) with 1674 participants, with mean age between 64.1 and 67.8 years. Follow-up ranged from 2 years to mean 4.3 years.For primary outcome measures, effect estimates from a single study showed uncertainty for the effect of NP-guided treatment on cardiovascular mortality in patients with cardiovascular risk factors and without heart failure (RR 0.33, 95% CI 0.04 to 3.17; 1 study; 300 participants; low-quality evidence). Pooled analysis demonstrated that in comparison to standard care, NP-guided treatment probably reduces the risk of cardiovascular hospitalisation (RR 0.52, 95% CI 0.40 to 0.68; 2 studies; 1674 participants; moderate-quality evidence). This corresponds to a risk of 163 per 1000 in the control group and 85 (95% CI 65 to 111) per 1000 in the NP-guided treatment group.When secondary outcome measures were evaluated, evidence from a pooled analysis showed uncertainty for the effect of NP-guided treatment on all-cause mortality (RR 0.90, 95% CI 0.60 to 1.35; 2 studies; 1354 participants; low-quality evidence). Pooled analysis indicates that NP-guided treatment probably reduces the risk of all-cause hospitalisation (RR 0.83, 95% CI 0.75 to 0.92; 2 studies; 1354 participants; moderate-quality evidence). This corresponds to a risk of 601 per 1000 in the control group and 499 (95% CI 457 to 553) per 1000 in the NP-guided treatment group. The effect estimate from a single study indicates that NP-guided treatment reduced the risk of ventricular dysfunction (RR 0.61, 95% CI 0.41 to 0.91; 1374 participants; high-quality evidence). The risk in this study's control group was 87 per 1000, compared with 53 (95% CI 36 to 79) per 1000 with NP-guided treatment. Results from the same study show that NP-guided treatment does not affect change in NP level at the end of follow-up, relative to standard care (MD -4.06 pg/mL, 95% CI -15.07 to 6.95; 1 study; 1374 participants; moderate-quality evidence).

AUTHORS' CONCLUSIONS

This review shows that NP-guided treatment is likely to reduce ventricular dysfunction and cardiovascular and all-cause hospitalisation for patients who have cardiovascular risk factors and who do not have heart failure. Effects on mortality and natriuretic peptide levels are less certain. Neither of the included studies were powered to evaluate mortality. Available evidence shows uncertainty regarding the effects of NP-guided treatment on both cardiovascular mortality and all-cause mortality; very low event numbers resulted in a high degree of imprecision in these effect estimates. Evidence also shows that NP-guided treatment may not affect NP level at the end of follow-up.As both trials included in our review were pragmatic studies, non-blinding of patients and practices may have biased results towards a finding of equivalence. Further studies with more adequately powered sample sizes and longer duration of follow-up are required to evaluate the effect of NP-guided treatment on mortality. As two trials are ongoing, one of which is a large multi-centre trial, it is hoped that future iterations of this review will benefit from larger sample sizes across a wider geographical area.

Clinical Meaning of the Ratio of Brachial Pre-Ejection Period to Brachial Ejection Time in Patients with Left Ventricular Systolic Dysfunction

An increase in the ratio of the brachial pre-ejection period to brachial ejection time [pre-ejection period (PEP)/ET] is correlated with a decrease of left ventricular ejection fraction (LVEF). The current study was designed to test the hypothesis that the change value (Δ) of PEP/ET is a useful indicator of Δ LVEF in patients with left ventricular systolic dysfunction.We consecutively enrolled 104 patients with left ventricular systolic dysfunction (LVEF < 45%). PEP/ET, B-type natriuretic peptide (BNP), and LVEF were evaluated at baseline and at 6-month follow-up. Compared with the baseline measurements, the 6-month values of ΔLVEF, ΔBNP, and ΔPEP/ET were 9.8% ± 9.0% (from 36.3% ± 9.2% to 46.3% ± 12.5%, P < 0.001), -168.5 ± 255.4 (from 271.4 ± 282.5 to 104.1 ± 129.6, P < 0.001), and -0.060 ± 0.069 (from 0.413 ± 0.097 to 0.358 ± 0.079, P < 0.001), respectively. There were significant correlations between LVEF and PEP/ET and between LVEF and BNP in both the initial (r = -0.316, P = 0.001 and r = -0.598, P < 0.001, respectively) and 6-month follow-up (r = -0.307, P = 0.003 and r = -0.701, P < 0.001, respectively). The Steiger's Z test showed that BNP had a significantly stronger correlation with LVEF compared with the correlations between LVEF and PEP/ET in both the initial and 6-month studies (Z = 2.471, P = 0.013 and Z = 3.575, P < 0.001, respectively). There were also significant correlations between ΔLVEF and ΔPEP/ET (r = -0.515, P < 0.001) and between ΔLVEF and ΔBNP (r = -0.581, P < 0.001); however, there was no difference between the correlations for ΔLVEF and ΔPEP/ET versus ΔLVEF and ΔBNP (Steiger's Z = 0.600, P = 0.545).In patients with left ventricular systolic dysfunction not only ΔBNP but also ΔPEP/ET could be a simple indicator of predicting change of LVEF.

SCReening Evaluation of the Evolution of New Heart Failure Study (SCREEN-HF): early detection of chronic heart failure in the workplace

Objective The aim of the present study was to determine whether asymptomatic heart failure (HF) in the workplace is subject to the health worker effect, making screening using conventional risk factors combined with a cardiac biomarker, namely N-terminal pro B-type natriuretic peptide (NT-proBNP), as useful as in the general population. Methods Between June 2007 and December 2009 a 'well' population deemed at high risk for development of HF was identified through health insurance records. Blood was collected from volunteer participants for analysis of urea, electrolytes and creatinine, a full blood count and NT-proBNP. An echocardiogram was performed on selected participants based on high NT-proBNP concentrations. Results The mean left ventricular ejection fraction (LVEF) was significantly reduced in participants with the highest compared with the lowest NT-proBNP quintile. In multivariate analysis, log-transformed NT-proBNP was independently associated with impaired LVEF and with moderate to severe diastolic dysfunction after adjustment for age, sex, coronary artery disease, diabetes, hypertension and obesity. Conclusions A large burden of asymptomatic left ventricular dysfunction (AVLD) was observed in subjects aged 60 and over with plasma NT-proBNP in the top quintile that was independent of conventional risk factors and work status. HWE does not appear to operate in AVLD. NT-proBNP testing in a population with HF risk factors may cost-effectively identify those at greatest risk of developing HF in a working population and facilitate early diagnosis, treatment and maintenance of work capacity. What is known about the topic? Chronic heart failure (CHF) has several causes, the most common being hypertension and coronary ischaemia. CHF is a major health problem of increasing prevalence that severely impacts quality of life, shortens lives and reduces worker productivity. It is often not diagnosed early enough to take full advantage of ameliorating medication. What does this paper add? Population screening for CHF is not currently advocated. This may be because conventional risk factors must be used in combination and there is no useful biomarker available. Yet evidence (SOLVD (Studies of Left Ventricular Dysfunction trials) recommends early diagnosis. We believe the work place is an area of potential screening where there is little supporting evidence. This paper provides evidence that the biomarker NT-proBNP is a useful new tool that improves cost-effectiveness of screening in a selected population. Specifically, the paper recommends CHF screening in the population with the highest potential health gain (i.e. the working population) by the sector with the highest economic gain (i.e. employers). What are the implications for practitioners? The paper presents important health screening recommendations for medical and health and safety practitioners within a selected population of workers. We feel practitioners should consider screening for incipient heart failure, particularly within Australia's working population, to save lives, provide economic benefit and extend working longevity.

A Survey of Coronary Risk Factors and B-Type Natriuretic Peptide Concentrations in Cardiac Nurses from Europe: Do Nurses Still Practice what they Preach?

BACKGROUND

From a previous survey of cardiac nurses attending a scientific conference, we learned that these nurses adopted a healthier lifestyle than the general population.

AIMS

The aim of this study was to determine the overall profile of cardiac risk factors in a similar cohort and determine whether cardiac nurses continue to 'practice what they preach' in this regard. Secondly, we examined the practical value of screening a large cohort of individuals within a short time frame (total of 8 hours screening time) and determined the range of BNP concentrations within a 'healthy' cohort.

METHODS

Data on CHD risk factors were collected with a short self-report questionnaire. The sample consisted of 122 cardiac nurses from 19 countries attending a European cardiac nursing conference held in Stockholm. A venous blood sample was collected into a tube containing potassium ETDA. B-type natriuretic peptide was measured on-site with the use of a portable fluorescence immunoassay kit.

RESULTS

Most participants were female (89%). Participants ranged in age from 23 to 60 years with a mean age of 41 (S.D. 9.4). Eleven percent - all female - reported they were current smokers, 27% (34) had a BMI >25 and 27% of the sample stated they did not exercise regularly. Almost half (48%) of the sample reported a family history of CHD. As expected, all BNP-values were within the normal range. There were significant differences in BNP on the basis of sex (P<0.05) and age (P<0.05) and a trend towards increasing BNP concentrations with progressively higher BMI scores (P=0.06).

CONCLUSION

This study reconfirms the likelihood that many cardiac nurses heed their own advice on lifestyle modification to reduce cardiovascular risk and therefore provide a good role model for the promotion of primary and secondary prevention initiatives.

Natriuretic peptides and integrated risk assessment for cardiovascular disease: an individual-participant-data meta-analysis

BACKGROUND

Guidelines for primary prevention of cardiovascular diseases focus on prediction of coronary heart disease and stroke. We assessed whether or not measurement of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) concentration could enable a more integrated approach than at present by predicting heart failure and enhancing coronary heart disease and stroke risk assessment.

METHODS

In this individual-participant-data meta-analysis, we generated and harmonised individual-participant data from relevant prospective studies via both de-novo NT-proBNP concentration measurement of stored samples and collection of data from studies identified through a systematic search of the literature (PubMed, Scientific Citation Index Expanded, and Embase) for articles published up to Sept 4, 2014, using search terms related to natriuretic peptide family members and the primary outcomes, with no language restrictions. We calculated risk ratios and measures of risk discrimination and reclassification across predicted 10 year risk categories (ie, <5%, 5% to <7·5%, and ≥7·5%), adding assessment of NT-proBNP concentration to that of conventional risk factors (ie, age, sex, smoking status, systolic blood pressure, history of diabetes, and total and HDL cholesterol concentrations). Primary outcomes were the combination of coronary heart disease and stroke, and the combination of coronary heart disease, stroke, and heart failure.

FINDINGS

We recorded 5500 coronary heart disease, 4002 stroke, and 2212 heart failure outcomes among 95 617 participants without a history of cardiovascular disease in 40 prospective studies. Risk ratios (for a comparison of the top third vs bottom third of NT-proBNP concentrations, adjusted for conventional risk factors) were 1·76 (95% CI 1·56-1·98) for the combination of coronary heart disease and stroke and 2·00 (1·77-2·26) for the combination of coronary heart disease, stroke, and heart failure. Addition of information about NT-proBNP concentration to a model containing conventional risk factors was associated with a C-index increase of 0·012 (0·010-0·014) and a net reclassification improvement of 0·027 (0·019-0·036) for the combination of coronary heart disease and stroke and a C-index increase of 0·019 (0·016-0·022) and a net reclassification improvement of 0·028 (0·019-0·038) for the combination of coronary heart disease, stroke, and heart failure.

INTERPRETATION

In people without baseline cardiovascular disease, NT-proBNP concentration assessment strongly predicted first-onset heart failure and augmented coronary heart disease and stroke prediction, suggesting that NT-proBNP concentration assessment could be used to integrate heart failure into cardiovascular disease primary prevention.

FUNDING

British Heart Foundation, Austrian Science Fund, UK Medical Research Council, National Institute for Health Research, European Research Council, and European Commission Framework Programme 7.

Cost-effectiveness of natriuretic peptide-based screening and collaborative care: a report from the STOP-HF (St Vincent's Screening TO Prevent Heart Failure) study

AIMS

Prevention of cardiovascular disease and heart failure (HF) in a cost-effective manner is a public health goal. This work aims to assess the cost-effectiveness of the St Vincent's Screening TO Prevent Heart Failure (STOP-HF) intervention.

METHODS AND RESULTS

This is a substudy of 1054 participants with cardiovascular risk factors [median age 65.8 years, interquartile range (IQR) 57.8:72.4, with 4.3 years, IQR 3.4:5.2, follow-up]. Annual natriuretic peptide-based screening was performed, with collaborative cardiovascular care between specialist physicians and general practitioners provided to patients with BNP levels >50 pg/mL. Analysis of cost per case prevented and cost-effectiveness per quality-adjusted life year (QALY) gained was performed. The primary clinical endpoint of LV dysfunction (LVD) with or without HF was reduced in intervention patients [odds ratio (OR) 0.60; 95% confidence interval (CI) 0.38-0.94; P = 0.026]. There were 157 deaths and/or emergency hospitalizations for major adverse cardiac events (MACE) in the control group vs. 102 in the intervention group (OR 0.68; 95% CI 0.49-0.93; P = 0.01). The cost per case of LVD/HF prevented was €9683 (sensitivity range -€843 to €20 210), whereas the cost per MACE prevented was €3471 (sensitivity range -€302 to €7245). Cardiovascular hospitalization savings offset increased outpatient and primary care costs. The cost per QALY gain was €1104 and the intervention has an 88% probability of being cost-effective at a willingness to pay threshold of €30 000.

CONCLUSION

Among patients with cardiovascular risk factors, natriuretic peptide-based screening and collaborative care reduced LVD, HF, and MACE, and has a high probability of being cost-effective.

TRIAL REGISTRATION

NCT00921960.

B-type natriuretic peptide and heart failure: what can we learn from clinical trials?

The B-type natriuretic peptide (BNP) may favour natriuresis and diuresis, making it an ideal drug to aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these has resulted in a better outcome. The current challenge for BNP research in acute HF lies in a failure of concept and reluctance to abandon a demonstrably ineffectual research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP as well as a better integration of basic and clinical science.

Cardiac troponin I levels in an elderly population from the community--The implications of sex

OBJECTIVES

The importance of sex on cardiac troponin levels is increasingly recognized. We investigated whether the entities associated with troponin leakage and the prognostic consequences thereof would differ between elderly men and women from the community.

DESIGN AND METHODS

Cardiac troponin I (cTnI) levels were measured using a high-sensitivity assay (Abbott Laboratories) in 70-year old men (n = 502) and women (n = 502) from the PIVUS study. All study participants were followed up for 10 years regarding all-cause mortality and incident cardiovascular (CV) disease.

RESULTS

Median cTnI levels were 4.1 and 3.0 ng/L in men and women, respectively (p<0.001). By multiple linear regression, the relative contribution of lower left-ventricular ejection fraction and ischemic ECG changes to cTnI levels was greater in men compared to women. For other clinical and echocardiographic variables, similar associations were found. cTnI independently predicted all-cause mortality in men (n = 93 [18.5%]; hazard ratio [HR] 1.38 [1.12-1.70]) and women (n = 62 [12.4%]; HR 1.59 [1.11-2.28]) but not incident CV disease in subjects being CV healthy at baseline (n = 163/857). The interaction terms of sex on the associations of cTnI with both outcomes were non-significant. Sex-specific cut-offs did not improve prognostication. Variations in the pattern of entities associated with cTnI leakage had no impact on event rates.

CONCLUSIONS

We found some differences in the entities associated with higher cTnI levels in elderly community-dwelling men and women. However, this did not translate into differences in the associations of cTnI with adverse outcome.

BNP and Heart Failure: Preclinical and Clinical Trial Data

The B-type natriuretic peptide (BNP), a member of the family of vasoactive peptides, has emerged as an important diagnostic, prognostic, and therapeutic tool in patients with heart failure (HF). The rapid incorporation into clinical practice of bioassays to BNP concentrations and pharmacological agents that augment the biological actions of this peptide such as nesiritide or vasopeptidase inhibitors has shown the potential for translational research to improve patient care. Despite the indirect evidence in support of a potential benefit from raising BNP, accumulating evidence suggests that simply increasing the amount of circulating BNP does not necessarily confer cardiovascular benefits in patient with HF. Moreover, in experimental HF, the response to treatments targeting specific natriuretic peptide receptors (NPRs) signaling seems to be attenuated. A better understanding of the NPRs signaling in HF would be clinically relevant and thus required, in order to devise strategies to develop novel agents and technologies that directly target this signaling pathway.

Review on natriuretic peptides: where we are, where we are going

BACKGROUND

Tremendous advances have been made in our understanding of the pathophysiology and treatment of congestive heart failure. However, diagnosis of the disease still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are nonspecific and insensitive indicators for heart failure, which can go largely undetected. Several studies have suggested the need for new diagnostic capabilities, especially with the increasing prevalence of heart failure in the US. The discovery of natriuretic peptides as diagnostic biomarkers has been one of the most critical advances for the management of heart failure. Both B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide have the potential to diagnose heart failure, assess prognostic risk of rehospitalization and mortality, and even help guide treatment. Their relative cost-effectiveness and availability have also facilitated their acceptance into many emergency departments, clinics and in-patient units as standard care when evaluating patients with suspected heart failure. Our understanding of the natriuretic peptide system is still in its infancy, but natriuretic peptides have emerged as important diagnostic and prognostic tools that have generated interest in finding broader applications for their use.

OBJECTIVE

The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in diagnosing and managing treatment of congestive heart failure.

METHOD

A comprehensive review of studies to assess the utility of natriuretic peptides for diagnosis and prognosis of heart failure and other conditions.

CONCLUSION

Natriuretic peptides are powerful tools to aid the physician in the diagnosis, prognosis and management of heart failure in both in-patient and out-patient settings. However, natriuretic peptides should be used as an adjunct test as many circumstances can also influence changes in natriuretic peptide levels.

Native myocardial T1 mapping by cardiovascular magnetic resonance imaging in subclinical cardiomyopathy in patients with systemic lupus erythematosus

BACKGROUND

Increased systemic inflammation has been linked to myocardial dysfunction and heart failure in patients with systemic lupus erythematosus (SLE). Accurate detection of early myocardial changes may be able to guide preventive intervention. We investigated whether multiparametric imaging by cardiovascular magnetic resonance can detect differences between controls and asymptomatic SLE patients.

METHODS AND RESULTS

A total of 33 SLE predominantly female patients (mean age, 40±9 years) underwent cardiovascular magnetic resonance for routine assessment of myocardial perfusion, function, and late gadolinium enhancement. T1 mapping was performed in single short-axis slice before and after 15 minutes of gadolinium administration. Twenty-one subjects with a low pretest probability and normal cardiovascular magnetic resonance served as a control group. Both groups had similar left ventricular volumes and mass and normal global systolic function. SLE patients had significantly reduced longitudinal strain (controls versus SLE, -20±2% versus -17±3%; P<0.01) and showed intramyocardial and pericardial late gadolinium enhancement. SLE patients had significantly increased native myocardial T1 (1056±27 versus 1152±46 milliseconds; P<0.001) and extracellular volume fraction (26±5% versus 30±6%; P=0.007) and reduced postcontrast myocardial T1 (454±53 versus 411±62 milliseconds; P=0.01). T1-derived indices were associated with longitudinal strain (r=0.37-0.47) but not with the presence of late gadolinium enhancement. Native myocardial T1 values showed the greatest concordance with the presence of clinical diagnosis of SLE.

CONCLUSIONS

In patients with SLE and free of cardiac symptoms, there is evidence of subclinical perimyocardial impairment. We further demonstrate that T1 mapping may have potential to detect subclinical myocardial involvement in patients with SLE.

The diagnostic utility of brain natriuretic peptide in heart failure patients presenting with acute dyspnea: a meta-analysis

Heart failure with normal ejection fraction (HFNEF) accounts for approximately 50% of heart failure (HF) cases. To establish the utility of brain natriuretic peptide (BNP) in differentiating HF-related severe dyspnea from non-HF-related acute dyspnea, we used an estimation formula (eF) that was obtained from a series of three meta-regressions. We selected 60 out of 2721 case-control and follow-up studies that were published from 1998 to 2010. The heart failure levels (HFLs) were assessed using the New York Heart Association (NYHA) criteria. Random-effects meta-regression analyses of the natural logarithm (ln) of the BNP odds ratio (OR) were performed on the HFLs. The ln of the median BNP values (lnmBNP) was meta-regressed over the laboratory method (LM). A third meta-regression was performed on the HFLs to account for only the lnmBNP in the homogeneous LM subgroups. To determine the eF, the data from the diseased and control subjects were combined. The Bland-Altman method was used to detect eF bias. The overall BNP(OR) in the subgroup with severe HF was 35. The lnmBNP analysis showed that LM was a significant heterogeneity factor in the meta-regression (slope −0.38; CI −0.59 to −0.16). The meta-regression of lnmBNP on the HFL resulted in the following calculation for eF: estimated HFL (eHFL)=(lnmBNP–3.157)/0.886. The Bland-Altman test revealed no significant difference (0.0997; 95% CI −2.84 to 3.06) between HFL and eHFL. The severe eHFL showed a 78% accuracy. Based on the eF obtained from this meta-analysis, the BNP outcomes were shown to reliably diagnose severe dyspnea in HF and differentiate this condition from non-HF acute dyspnea.

Prognostic usefulness of the change in N-terminal pro B-type natriuretic peptide levels to predict mortality in a single community cohort aged ≥ 70 years

The levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) are closely related to cardiac abnormalities and adverse outcomes in the general population. However, little is known about the course of NT-proBNP levels over time, the underlying conditions, and the prognostic effect of changes. To investigate these issues, we measured the NT-proBNP levels (Elecsys 2010, Roche Diagnostics) in community-dwellers participating in the Prospective Investigation of the Vasculature in Uppsala Seniors study at 70 (n = 1,005) and 75 (n = 817) years of age. The total follow-up was 8.0 years. In subjects with available results from both examinations, the median NT-proBNP levels increased from 106 pg/ml (25th to 75th percentile 62 to 174) to 125 pg/ml (25th to 75th percentile 73-234; p <0.001). The change in NT-proBNP levels was positively and independently related to male gender, baseline information on ischemic electrocardiographic changes, renal dysfunction, impaired left ventricular ejection fraction, and intercurrent cardiovascular events (e.g., myocardial infarction, stroke, or coronary revascularization). The change in NT-proBNP levels independently predicted mortality after the measurements at 75 years of age (all-cause mortality, adjusted hazard ratio 2.4, 95% confidence interval 1.6 to 3.6; cardiovascular mortality, adjusted hazard ratio 2.3, 95% confidence interval 1.2 to 4.5). Compared to those without significant NT-proBNP changes (n = 606), subjects with increasing levels (n = 162) had markedly increased all-cause mortality (adjusted hazard ratio 4.3, 95% confidence interval 2.1 to 8.8). No subject with decreasing NT-proBNP levels (n = 49) died. In conclusion, repeat measurements of NT-proBNP might add useful information to the routine clinical assessment in subjects aged ≥ 70 years, because changes in their levels were associated with cardiovascular risk indicators and strongly predictive of mortality.

Echocardiography, natriuretic peptides, and risk for incident heart failure in older adults: the Cardiovascular Health Study

OBJECTIVES

This study sought to examine the potential utility of echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) for heart failure (HF) risk stratification in concert with a validated clinical HF risk score in older adults.

BACKGROUND

Without clinical guidance, echocardiography and natriuretic peptides have suboptimal test characteristics for population-wide HF risk stratification. However, the value of these tests has not been examined in concert with a clinical HF risk score.

METHODS

We evaluated the improvement in 5-year HF risk prediction offered by adding an echocardiographic score and/or NT-proBNP levels to the clinical Health Aging and Body Composition (ABC) HF risk score (base model) in 3,752 participants of the CHS (Cardiovascular Health Study) (age 72.6 ± 5.4 years; 40.8% men; 86.5% white). The echocardiographic score was derived as the weighted sum of independent echocardiographic predictors of HF. We assessed changes in Bayesian information criterion (BIC), C index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI). We examined also the weighted NRI across baseline HF risk categories under multiple scenarios of event versus nonevent weighting.

RESULTS

Reduced left ventricular ejection fraction, abnormal E/A ratio, enlarged left atrium, and increased left ventricular mass were independent echocardiographic predictors of HF. Adding the echocardiographic score and NT-proBNP levels to the clinical model improved BIC (echocardiography: -43, NT-proBNP: -64.1, combined: -68.9; all p < 0.001) and C index (baseline: 0.746; echocardiography: +0.031, NT-proBNP: +0.027, combined: +0.043; all p < 0.01), and yielded robust IDI (echocardiography: 43.3%, NT-proBNP: 42.2%, combined: 61.7%; all p < 0.001), and NRI (based on Health ABC HF risk groups; echocardiography: 11.3%; NT-proBNP: 10.6%, combined: 16.3%; all p < 0.01). Participants at intermediate risk by the clinical model (5% to 20% 5-yr HF risk; 35.7% of the cohort) derived the most reclassification benefit. Echocardiography yielded modest reclassification when used sequentially after NT-proBNP.

CONCLUSIONS

In older adults, echocardiography and NT-proBNP offer significant HF risk reclassification over a clinical prediction model, especially for intermediate-risk individuals.

Comparison between immunoradiometric and fluorimetric brain natriuretic peptide determination in patients with congestive heart failure

This study compared two different methods, namely the immunoradiometric (IRMA) and fluorimetric (FIA), in order to determine plasma brain natriuretic peptide (BNP) in congestive heart failure (CHF) patients.

METHODS

CHF in-patients underwent echocardiography and plasma BNP determination using both two methods. The echocardiograms analysed left ventricular end-systolic (LVESV) and end-diastolic (LVEDV) volumes and systolic dysfunction [left ventricular ejection fraction (LVEF) <50%].

RESULTS

Seventy-three (71% males, age 67 ± 9.6 yr) patients were enrolled, 31.5% affected by valvular heart disease. The mean LVEF was 39.8 ± 14.1%; in 26 (35%) a hypertensive etiology emerged. The immunoradiometric assay (IRMA) BNP was found to be significantly lower than the FIA determination 116.5 ± 149 pg/ml vs 267.3 ± 285.6 pg/ml; p=0.0001) and the two methods were closely correlated (r=0.89; p=0.00001). Logistic regression demonstrated a significant correlation between BNP, LVEF, and LVESV/LVEDV (r=-0.45, p=0.0003; r=-0.48, p=0.00001; r=0.22 p=0.003; r=0.34 p=0.0001; r=0.13 p=0.02; r=0.28 p=0.001 IRMA and FIA, respectively). IRMA BNP and FIA BNP significantly increased according to the worsening functional class [from 34.3 ± 60.2 pg/ml in NYHA (New York Heart Association) I to 555.5 ± 273.1 pg/ml in NYHA IV; from 86.1 ± 162.1 pg/ml in NYHA I to 1070 ± 42.2 pg/ml in NYHA IV, respectively]. In severe systolic dysfunction (LVEF<30%), receiver operating characteristic analysis revealed a satisfactorily sensitivity and specificity using a cut-off point of 50.6 pg/ml with IRMA and 243 pg/ml with FIA. In mild systolic dysfunction (LVEF<50%), a good sensitivity and specificity using a cut-off point of 42 pg/ml with IRMA and 182 pg/ml with FIA emerged.

CONCLUSIONS

In CHF patients both BNP methods correlated with NYHA class, LVEF, and ventricular volumes.

Endothelial dysfunction, measured by reactive hyperaemia using strain-gauge plethysmography, is an independent predictor of adverse outcome in heart failure

AIMS

In congestive heart failure (CHF), arterial response is regulated by endothelial molecules. The aim of this study was to evaluate whether endothelial dysfunction (ED) was a predictor of outcome in a cohort of patients with heart failure.

METHODS AND RESULTS

Endothelial function was assessed in 242 patients with CHF by forearm reactive hyperaemia measured with intermittent venous occlusion plethysmography using a mercury strain gauge. The main endpoints were: 'total events' (death, heart attack, angina, stroke, NYHA class IV, or hospitalization due to heart failure) analysed using Cox regression for repeated events and 'death'. Patients were followed-up for 5 years. Post-hyperaemia forearm blood flow (PHFABF) was an independent predictor of total events [P = 0.01; hazard ratio [Exp(B)] 0.665, standard error (SE) 0.182]. Risk stratification by basal forearm blood flow (BFABF) showed that patients with basal blood flow above the median (3.03 mL min(-1) 100 mL(-1)) benefited from an increase in PHFABF, whereas in patients with a BFABF below the median, the increase in PHFABF did not diminish the risk of events. There was no relation between variations in PHFABF and death.

CONCLUSION

Post-hyperaemia forearm blood flow, as a measure of ED, is an independent predictor of major events in patients with CHF. A BFABF below the median is more predictive of an increased risk of complications.

Natriuretic Peptides and Assessment of Cardiovascular Disease Risk in Asymptomatic Persons

Current tools for cardiovascular disease (CVD) risk assessment in asymptomatic individuals are imperfect. Preventive measures aimed only at individuals deemed high risk by current algorithms neglect large numbers of low-risk and intermediate-risk individuals who are destined to develop CVD and who would benefit from early and aggressive treatment. Natriuretic peptides have the potential both to identify individuals at risk for future cardiovascular events and to help detect subclinical CVD. Choosing the appropriate subpopulation to target for natriuretic peptide testing will help maximize the performance and the cost effectiveness. The combined use of multiple risk markers, including biomarkers, genetic testing, and imaging or other noninvasive measures of risk, offers promise for further refining risk assessment algorithms. Recent studies have highlighted the utility of natriuretic peptides for preoperative risk stratification; however, cost effectiveness and outcomes studies are needed to affirm this and other uses of natriuretic peptides for cardiovascular risk assessment in asymptomatic individuals.

Biochemical Cardiac Risk Markers in the General Population, Hypertension and Coronary Artery Disease

Recently there has been a growing interest in risk assessment of individuals, using biochemical markers of cardiac risk, with an increasing focus on a multi-marker strategy. Natriuretic peptides (BNP and NT-proBNP) are well-established markers of increased risk in the general population and in high-risk groups with hypertension, and coronary heart disease. However, there is at present no indication for routine measurements of natriuretic peptides in the risk assessment of individuals or patients, as there is no evidence for subsequent therapeutic initiatives. Natriuretic peptides are useful when screening for heart failure in symptomatic individuals. However, the use of NT-proBNP screening for risk or left ventricular systolic dysfunction in the general population is still a matter of debate.

ProBNP‐derived peptides in cardiac disease

The natriuretic peptides constitute a family of structurally related peptides that regulate fluid homeostasis, vascular tonus and growth. After the discovery of an endocrine component of the heart almost 25 years ago, the cardiac natriuretic peptides have now been fully accepted as useful markers in diverse aspects of cardiology including as diagnostic, therapeutic and prognostic markers of cardiac disease. In humans, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are mainly synthesized and secreted by the failing heart, whereas the related C-type natriuretic peptide (CNP) appears to be a local regulatory peptide secreted by the vascular endothelium. Accordingly, CNP is not a cardiac peptide. With the recent implementation of sensitive and specific immunoassays, increased plasma concentrations of proBNP-derived peptides have now been associated with several cardiac conditions, where the major application today seems related to ventricular dysfunction. Recently, focus has also turned to ischemic heart disease, since myocardial hypoxia increases the local BNP gene expression. This review recapitulates the established clinical applications of measuring proBNP-derived peptides in plasma. Furthermore, the evidence of increased cardiac BNP expression in ischemic heart disease will be emphasized. In turn, plasma measurement of proBNP-derived peptides may still hold new possibilities in screening for coronary artery disease.

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.

Accuracy of N-terminal pro-brain natriuretic peptide in the identification of left ventricular dysfunction in high-risk asymptomatic patients

OBJECTIVE

The role of natriuretic peptides in the screening of left ventricular dysfunction is still unclear. The aim of this study was to assess the usefulness of N-terminal pro-brain natriuretic peptide (NT-proBNP) measurement in asymptomatic patients at high risk of developing left ventricular dysfunction.

METHODS

One hundred and thirty-four consecutive ambulatory patients (mean age 56.1 +/- 7 years) were studied and selected on the basis of a history of hypertension of at least 5 years. Systolic dysfunction was defined as an ejection fraction of 45% or less. Statistical analysis was performed by both parametric and nonparametric approaches. Diagnostic accuracy was evaluated by receiver operating characteristic analysis.

RESULTS

Echocardiography showed normal left ventricular function in 40 patients, diastolic dysfunction in 80 patients and systolic dysfunction in 14 patients. NT-proBNP levels were significantly higher in patients with systolic dysfunction (356.1 +/- 294.8 vs. 85.2 +/- 85.8 pg/ml; P < 0.05). Receiver operating characteristic analysis showed a high value of the area under the curve (0.89) for the detection of systolic dysfunction with a sensitivity of 83% and a specificity of 80% for a cut-off value of 114 pg/ml and with a negative predictive value of 0.98.

CONCLUSION

In asymptomatic patients at high risk for heart failure because of a history of hypertension, the measurement of NT-proBNP levels may represent a useful screening test for left ventricular systolic dysfunction. Therefore, more expensive examinations, such as echocardiography, may be restricted only to patients with higher NT-proBNP levels.

Prognostic threshold levels of NT-proBNP testing in primary care

AIMS

Chronic heart failure (HF) is a common condition with a poor prognosis. As delayed diagnosis and treatment of HF patients in primary care can be detrimental, risk-stratified waiting lists for echocardiography might optimize resource utilization. We investigated whether a prognostic threshold level of the cardiac peptide, NT-proBNP, could be identified.

METHODS AND RESULTS

From 2003-2005, 5875 primary care patients with suspected HF (median age 73 years) had NT-proBNP analysed in the Copenhagen area. Eighteen percent died and 20% had a cardiovascular (CV) hospitalization (median follow-up time: 1127 and 1038 days, respectively). In Cox proportional hazards regression models regarding NT-proBNP levels, the fourth decile (range: 83-118 pg/mL) was associated with a 90% (95% CI: 30-190, P < 0.01) increased risk for CV hospitalization and the seventh decile (range: 229-363 pg/mL) was associated with an 80% (95% CI: 20-190, P = 0.01) increased mortality risk after adjustment for age, sex, previous hospitalization, CV diseases, and chronic diseases.

CONCLUSION

We identified prognostic threshold levels for mortality and CV hospitalization for NT-proBNP in primary care patients suspected of HF. Our results have the potential to be used to risk-stratify waiting lists for echocardiography.

Cost-effectiveness of B-type natriuretic peptide testing

As with any other diagnostic method, the cost-effectiveness of B-type natriuretic peptide (BNP) testing depends on the indication of its use and the specific clinical setting. The use of BNP levels, in conjunction with other clinical information, provides information that seems to be particularly helpful in the diagnosis, prognosis, and management of heart failure (HF) as well as screening for left ventricular systolic dysfunction. In the screening for asymptomatic left ventricular systolic dysfunction, BNP testing seems to be cost-effective (<$50,000 per quality-adjusted life-years gained) when used in a population with a prevalence of at least 1%. BNP testing, in fact, results in cost savings in the diagnosis of HF. Although the data are less robust, BNP seems cost-effective in the risk stratification of hospitalized HF patients when compared with echocardiography. Because BNP guidance seems to reduce the number of rehospitalizations in recently hospitalized patients with chronic HF, the use of BNP is also most likely cost-effective in this indication. For the remaining and, in part, evolving indications, further studies are needed to assess cost-effectiveness.

Troponins and natriuretic peptides in the monitoring of anthracycline cardiotoxicity

Anthracycline-related cardiotoxicity has a substantial negative impact on long-term survivors of childhood cancer. The detection of cardiotoxicity is currently based on echocardiography or radionuclide angiography. However, as they depict only the final outcome of myocardial injury in terms of reduced heart contractility, heart specific biomarkers of myocardial destruction or dysfunction could be advantageous by allowing for an earlier detection of cardiotoxicity. In the present study, the usefulness of cardiac troponins and natriuretic peptides, the most commonly used biomarkers of myocardial destruction and ventricular dysfunction respectively, to detect and to predict the development of anthracycline cardiotoxicity has been reviewed.

State of the art: using natriuretic peptide levels in clinical practice

Natriuretic peptide (NP) levels (B-type natriuretic peptide (BNP) and N-terminal proBNP) are now widely used in clinical practice and cardiovascular research throughout the world and have been incorporated into most national and international cardiovascular guidelines for heart failure. The role of NP levels in state-of-the-art clinical practice is evolving rapidly. This paper reviews and highlights ten key messages to clinicians: 1) NP levels are quantitative plasma biomarkers of heart failure (HF). 2) NP levels are accurate in the diagnosis of HF. 3) NP levels may help risk stratify emergency department (ED) patients with regard to the need for hospital admission or direct ED discharge. 4) NP levels help improve patient management and reduce total treatment costs in patients with acute dyspnoea. 5) NP levels at the time of admission are powerful predictors of outcome in predicting death and re-hospitalisation in HF patients. 6) NP levels at discharge aid in risk stratification of the HF patient. 7) NP-guided therapy may improve morbidity and/or mortality in chronic HF. 8) The combination of NP levels together with symptoms, signs and weight gain assists in the assessment of clinical decompensation in HF. 9) NP levels can accelerate accurate diagnosis of heart failure presenting in primary care. 10) NP levels may be helpful to screen for asymptomatic left ventricular dysfunction in high-risk patients.

Diagnostic performance and cost effectiveness of measurements of plasma N-terminal pro brain natriuretic peptide in patients presenting with acute dyspnea or peripheral edema

BACKGROUND

The purpose of this study was to determine the diagnostic power of a newly available assay for amino-terminal pro-brain natriuretic peptide (NT-proBNP) to identify patients with acute heart failure. In addition, the influence of initial NT-proBNP measurements on economic consequences, diagnostic procedures and staff involvement was evaluated.

METHODS AND RESULTS

401 patients presenting with acute dyspnea or peripheral edema in the emergency department were enrolled. NT-proBNP was measured after initial clinical evaluation. Clinical routine care and diagnostic assessment were blinded to NT-proBNP results. Two cardiologists independently validated the period of hospitalization, clinical examinations and medical therapies of each patient considering NT-proBNP results. The median NT-proBNP level among patients with acute congestive heart failure (CHF) (n=122) was 3497 pg/ml as compared to 320 pg/ml in patients without (n=279) (p<0.0001). An NT-proBNP cutoff level <300 pg/ml was optimal to rule out acute CHF (negative predictive value 96%; sensitivity 96%). NT-proBNP >or=300 pg/ml could strongly predict acute CHF when compared to patients' history or physical examination (odds ratio 9.5; p<0.0001) and diagnostic technical findings (odds ratio 14.7; p<0.05). In patients with NT-proBNP<300 pg/ml, 14% of the period of hospitalization could be saved, corresponding to savings of US $481 per patient. In addition, 9% of the number and time of staff involvement of clinical examinations and therapies could be saved, 10% of the costs of clinical examinations. Chest X-rays were saved in 34%, echocardiography in 9%.

CONCLUSIONS

Measurement of NT-proBNP leads to multiple saving amounts and optimizes diagnostic pathways and resource allocation.