N-terminal pro-brain natriuretic peptide testing in the emergency department: beneficial effects on hospitalization, costs, and outcome

The cost-effectiveness of NT-proBNP for assessment of suspected acute heart failure in the emergency department

AIMS

When relying on clinical assessment alone, an estimated 22% of acute heart failure (AHF) patients are missed, so clinical guidelines recommend the use of N-terminal pro-B-type natriuretic peptide (NT-proBNP) for AHF diagnosis. Since publication of these guidelines, there has been poor uptake of NT-proBNP testing in part due to concerns over excessive false positive referrals resulting from the low specificity of a single 'rule-out' threshold of <300 pg/mL. Low specificity can be mitigated by the addition of age-specific 'rule-in' NT-proBNP thresholds.

METHODS AND RESULTS

A theoretical hybrid decision tree/semi-Markov model was developed, combining global trial and audit data to evaluate the cost-effectiveness of NT-proBNP testing using age-specific rule-in/rule-out (RI/RO) thresholds, compared with NT-proBNP RO only and with clinical decision alone (CDA). Cost-effectiveness was measured as the incremental cost per quality-adjusted life year (QALY) gained and incremental net health benefit. In the base case, using UK-specific inputs, NT-proBNP RI/RO was associated with both greater QALYs and lower costs than CDA. At a willingness-to-pay threshold of £20 000/QALY, NT-proBNP RO was also cost-effective compared with CDA [incremental cost-effectiveness ratio (ICER) of £8322/QALY], but not cost-effective vs. RI/RO (ICER of £64 518/QALY). Overall, NT-proBNP RI/RO was the most cost-effective strategy. Sensitivity and scenario analyses were undertaken; the conclusions were not impacted by plausible variations in parameters, and similar conclusions were obtained for the Netherlands and Spain.

CONCLUSIONS

An NT-proBNP strategy that combines an RO threshold with age-specific RI thresholds provides a cost-effective alternative to the currently recommended NT-proBNP RO only strategy, achieving greater diagnostic specificity with minimal reduction in sensitivity and thus reducing unnecessary echocardiograms and hospital admissions.

Rapid N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) Kit as a Differentiating Tool for Acute Dyspnea in a Resource-Limited Setting

Introduction Dyspnea is among the most prevalent symptoms experienced by patients presenting as an emergency. The underlying etiology is often a cardiovascular or pulmonary condition, of which heart failure is recognized as a major contributor. The differentials are primarily established based on the patient's clinical presentation and physical examinations but are not conclusive. Of the various investigations undertaken to determine the cause of dyspnea, the biomarker N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) was found to be significantly associated with heart failure. Its level has been proven to be in direct correlation with the severity of the disease. This study demonstrates the usability of an economical rapid test kit in measuring NT-ProBNP levels to help differentiate the cause of dyspnea in the presenting patient in a resource-limited setting. Methodology We studied 115 participants from a tertiary care center in India, which included 70 males and 45 females aged ≤30 to ≥75 years, presenting with shortness of breath. Rapid NT-ProBNP tests were conducted alongside recording their symptoms, vitals, examination findings, and other parameters. They were also classified according to New York Heart Association (NYHA) Classification, and further investigated. Results The study elucidated the efficacy and accuracy of the rapid kits in determining NT-ProBNP levels, and its relation with the severity and prognosis of heart failure. The kits utilized had a sensitivity of greater than 93% for ruling out heart failure as a cause of dyspnea, and a sensitivity of greater than 96% for ruling out elevated NT-ProBNP levels in general. Other parameters such as presenting symptoms and vitals were also analyzed, establishing a correlation with NT-ProBNP levels.  Conclusion This study guided us in understanding the effective utilization of the rapid testing kits for emergency care, minimizing the burden on other limited resources. The lower cost and ease of use would serve as a quick means of reaching a conclusive diagnosis, especially in an emergency, which in turn would aid in receiving timely and specific treatment. These kits could act as a stepping stone in creating a sustainable and efficient healthcare system for patients as well as healthcare workers.

N-Terminal Pro B-Type Natriuretic Peptide as a Screening Tool for Inpatient Echocardiogram Requirement Among Patients With Suspected Heart Failure: Using NT-proBNP to Reduce Hospital Length of Stay

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker with diagnostic and prognostic utility in patients with heart failure (HF). Whether NT-proBNP can be used to triage inpatient transthoracic echocardiogram (TTE) requirements, and whether this impacts hospital length of stay (LOS), is not clear.

METHODS

Clinical and biochemical data were prospectively recorded on all inpatients at Wollongong Hospital, NSW, Australia, who had a TTE ordered for suspected HF over a 6-month period. NT-proBNP was used to triage TTE priority, where high-priority inpatient TTE, lower-priority inpatient TTE and outpatient (OP) TTE were performed for serum NT-proBNPs of ≥900, 300-899 and <300, respectively. Outcomes were compared with a baseline cohort of HF inpatients in whom TTE requirement was not guided by NT-proBNP.

RESULTS

A total of 236 patients were evaluated-31, 31, and 174 in the low, intermediate and high NT-proBNP cohorts, respectively, and 199 patients were in the baseline cohort. Average hospital LOS was significantly reduced in the study cohort compared to baseline (9.97 vs 13.87 days, p<0.001). Of the 31 patients with a very low NT-proBNP who were discharged for OP TTE, seven were readmitted within 30 days, though none were HF-related. There were no deaths at 30 days in the low or intermediate NT-proBNP groups.

CONCLUSIONS

Using NT-proBNP to triage requirements for inpatient TTE reduces hospital LOS. A very low NT-proBNP may help identify which patients with suspected HF can be safely discharged for OP TTE.

Development and validation of a decision support tool for the diagnosis of acute heart failure: systematic review, meta-analysis, and modelling study

OBJECTIVES

To evaluate the diagnostic performance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) thresholds for acute heart failure and to develop and validate a decision support tool that combines NT-proBNP concentrations with clinical characteristics.

DESIGN

Individual patient level data meta-analysis and modelling study.

SETTING

Fourteen studies from 13 countries, including randomised controlled trials and prospective observational studies.

PARTICIPANTS

Individual patient level data for 10 369 patients with suspected acute heart failure were pooled for the meta-analysis to evaluate NT-proBNP thresholds. A decision support tool (Collaboration for the Diagnosis and Evaluation of Heart Failure (CoDE-HF)) that combines NT-proBNP with clinical variables to report the probability of acute heart failure for an individual patient was developed and validated.

MAIN OUTCOME MEASURE

Adjudicated diagnosis of acute heart failure.

RESULTS

Overall, 43.9% (4549/10 369) of patients had an adjudicated diagnosis of acute heart failure (73.3% (2286/3119) and 29.0% (1802/6208) in those with and without previous heart failure, respectively). The negative predictive value of the guideline recommended rule-out threshold of 300 pg/mL was 94.6% (95% confidence interval 91.9% to 96.4%); despite use of age specific rule-in thresholds, the positive predictive value varied at 61.0% (55.3% to 66.4%), 73.5% (62.3% to 82.3%), and 80.2% (70.9% to 87.1%), in patients aged <50 years, 50-75 years, and >75 years, respectively. Performance varied in most subgroups, particularly patients with obesity, renal impairment, or previous heart failure. CoDE-HF was well calibrated, with excellent discrimination in patients with and without previous heart failure (area under the receiver operator curve 0.846 (0.830 to 0.862) and 0.925 (0.919 to 0.932) and Brier scores of 0.130 and 0.099, respectively). In patients without previous heart failure, the diagnostic performance was consistent across all subgroups, with 40.3% (2502/6208) identified at low probability (negative predictive value of 98.6%, 97.8% to 99.1%) and 28.0% (1737/6208) at high probability (positive predictive value of 75.0%, 65.7% to 82.5%) of having acute heart failure.

CONCLUSIONS

In an international, collaborative evaluation of the diagnostic performance of NT-proBNP, guideline recommended thresholds to diagnose acute heart failure varied substantially in important patient subgroups. The CoDE-HF decision support tool incorporating NT-proBNP as a continuous measure and other clinical variables provides a more consistent, accurate, and individualised approach.

STUDY REGISTRATION

PROSPERO CRD42019159407.

Activity of the adrenomedullin system to personalise post-discharge diuretic treatment in acute heart failure

Background

Quantifying the activity of the adrenomedullin system might help to monitor and guide treatment in acute heart failure (AHF) patients. The aims were to (1) identify AHF patients with marked benefit or harm from specific treatments at hospital discharge and (2) predict mortality by quantifying the adrenomedullin system activity.

Methods

This was a prospective multicentre study. AHF diagnosis and phenotype were centrally adjudicated by two independent cardiologists among patients presenting to the emergency department with acute dyspnoea. Adrenomedullin system activity was quantified using the biologically active component, bioactive adrenomedullin (bio-ADM), and a prohormone fragment, midregional proadrenomedullin (MR-proADM). Bio-ADM and MR-proADM concentrations were measured in a blinded fashion at presentation and at discharge. Interaction with specific treatments at discharge and the utility of these biomarkers on predicting outcomes during 365-day follow-up were assessed.

Results

Among 1886 patients with adjudicated AHF, 514 patients (27.3%) died during 365-day follow-up. After adjusting for age, creatinine, and treatment at discharge, patients with bio-ADM plasma concentrations above the median (> 44.6 pg/mL) derived disproportional benefit if treated with diuretics (interaction p values < 0.001). These findings were confirmed when quantifying adrenomedullin system activity using MR-proADM (n = 764) (interaction p values < 0.001). Patients with bio-ADM plasma concentrations above the median were at increased risk of death (hazard ratio 1.87, 95% CI 1.57–2.24; p < 0.001). For predicting 365-day all-cause mortality, both biomarkers performed well, with MR-proADM presenting an even higher predictive accuracy compared to bio-ADM (p < 0.001).

Conclusions

Quantifying the adrenomedullin’s system activity may help to personalise post-discharge diuretic treatment and enable accurate risk-prediction in AHF.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01909-9.

Aldosterone-producing adenoma associated with non-suppressed renin: a case series

Although the aldosterone/renin ratio (ARR) is the preferred screening test for primary aldosteronism (PA), patients with non-suppressed renin and a falsely negative ARR on non-interfering medications have occasionally been reported. This report describes the clinical characteristics and outcomes of seven patients with proven aldosterone-producing adenoma (APA) and non-suppressed renin.Chart review of seven PA patients with an APA and a non-suppressed plasma renin concentration (PRC > 8.4 mU/L) was undertaken to collect data on anthropometric and biochemical characteristics, diagnostic evaluation and postsurgical outcomes.Seven patients (two women and five men) with a proven APA had median (range) PRC, plasma aldosterone and ARR of 20 (9-43) mU/L, 750 (270-1940) pmol/L and 45 (8-62, normal <70), respectively, on non-interfering medications. Six patients had two consecutive ARR measurements and in five of them both were normal. Renal artery stenosis was carefully excluded in all patients. Further evaluation for PA was pursued because of high clinical suspicion (either hypokalaemia and/or a known adrenal mass lesion on imaging). All underwent adrenal vein sampling confirming unilateral PA which was managed by unilateral adrenalectomy. Postsurgical follow-up data either confirmed or were highly suggestive of cure of PA.Strict control of factors known to influence the ARR is crucial to avoid false-negative results. Other causes that could explain a non-suppressed renin should be excluded. In patients with a consistently non-suppressed renin further diagnostic workup for PA should be considered if clinical suspicion remains high.

Diagnosis of Acute Heart Failure in the Emergency Department: An Evidence-Based Review

Heart failure is a common presentation to the emergency department (ED), which can be confused with other clinical conditions. This review provides an evidence-based summary of the current ED evaluation of heart failure. Acute heart failure is the gradual or rapid decompensation of heart failure, resulting from either fluid overload or maldistribution. Typical symptoms can include dyspnea, orthopnea, or systemic edema. The physical examination may reveal pulmonary rales, an S3 heart sound, or extremity edema. However, physical examination findings are often not sensitive or specific. ED assessments may include electrocardiogram, complete blood count, basic metabolic profile, liver function tests, troponin, brain natriuretic peptide, and a chest radiograph. While often used, natriuretic peptides do not significantly change ED treatment, mortality, or readmission rates, although they may decrease hospital length of stay and total cost. Chest radiograph findings are not definitive, and several other conditions may mimic radiograph findings. A more reliable modality is point-of-care ultrasound, which can facilitate the diagnosis by assessing for B-lines, cardiac function, and inferior vena cava size. These modalities, combined with clinical assessment and gestalt, are recommended.

Biomarkers in diagnosing and treatment of acute heart failure

Acute heart failure (AHF) is a complex disorder involving different pathophysiological pathways. In recent years, there is an increased focus on biomarkers that help with diagnosis, risk stratification and disease monitoring of AHF. Finding a reliable set of biomarkers not only improves morbidity and mortality but it can also potentially reveal the new targets of therapy. In this paper, we have reviewed the biomarkers found useful for the diagnosis as well as for risk stratification and prognostication in patients with AHF. We have discussed the established biomarkers for AHF including cardiac troponins and natriuretic peptides and emerging biomarkers including adiponectin, mi-RNA, sST2, Gal-3, MR-proADM, OPG, CT-proAVP and H-FABP for the purposes of making diagnosis, their use as a guide of therapy or for determination of prognosis.

Comparison of the Diagnostic Accuracy of Plasma N-Terminal Pro-Brain Natriuretic Peptide in Patients <80 to those >80 Years of Age with Heart Failure

Plasma N-Terminal Pro-Brain Natriuretic Peptide (NTproBNP) is known to increase with age, however, the performance of this biomaker is unclear in patients >80. This study sought to define the diagnostic accuracy of plasma NTproBNP in patients >80 in a large unselected population of heart failure (HF) patients admitted to a Tertiary Hospital in the United Kingdom. 1,995 consecutive patients over a 12 month period were screened for HF through our NTproBNP led HF service. 413 patients had their first presentation of HF and 36.1% of these patients were >80. There was a reduction in accuracy of NTproBNP with age according to the area under the curve, with an area under the curve for all HF patients of 0.734 and a 7.5% reduction in receiver operating characteristic curve area for patients >80 years compared with those under 60 to 79 years of age. The lowest NTproBNP recorded for patients with HF >80 years of age was 466 pg/ml. In HF patients >80, 40.6% patients were diagnosed with HFrEF, 31.1% with HFpEF and 28.2% with HFmrEF. Overall NTproBNP is less accurate at identifying HF in patients >80 years of age and the lowest NTproBNP recorded for a HF patient was 466 pg/ml suggesting that the NTproBNP threshold for ruling out HF in patients >80 years of age should be modified.

Misconceptions in acute heart failure diagnosis and Management in the Emergency Department

INTRODUCTION

Acute heart failure (AHF) accounts for a significant number of emergency department (ED) visits, and the disease may present along a spectrum with a variety of syndromes.

OBJECTIVE

This review evaluates several misconceptions concerning heart failure evaluation and management in the ED, followed by several pearls.

DISCUSSION

AHF is a heterogeneous syndrome with a variety of presentations. Physicians often rely on natriuretic peptides, but the evidence behind their use is controversial, and these should not be used in isolation. Chest radiograph is often considered the most reliable imaging test, but bedside ultrasound (US) provides a more sensitive and specific evaluation for AHF. Diuretics are a foundation of AHF management, but in pulmonary edema, these medications should only be provided after vasodilator administration, such as nitroglycerin. Nitroglycerin administered in high doses for pulmonary edema is safe and effective in reducing the need for intensive care unit admission. Though classically dopamine is the first vasopressor utilized in patients with hypotensive cardiogenic shock, norepinephrine is associated with improved outcomes and lower mortality. Disposition is complex in patients with AHF, and risk stratification tools in conjunction with other assessments allow physicians to discharge patients safely with follow up.

CONCLUSION

A variety of misconceptions surround the evaluation and management of heart failure including clinical assessment, natriuretic peptide use, chest radiograph and US use, nitroglycerin and diuretics, vasopressor choice, and disposition. This review evaluates these misconceptions while providing physicians with updates in evaluation and management of AHF.

A cost effectiveness study establishing the impact and accuracy of implementing the NICE guidelines lowering plasma NTproBNP threshold in patients with clinically suspected heart failure at our institution

AIMS

The 2014 National Institute of Clinical Excellence (NICE) guidelines on the management of acute heart failure recommended using a plasma NT-proBNP threshold of 300pg/ml to assist in ruling out the diagnosis of heart failure (HF), updating previous guidelines recommending using a threshold of 400pg/ml. NICE based their recommendations on 6 studies performed in other countries. This study sought to determine the diagnostic and economic implications of using these thresholds in a large unselected UK population.

METHODS

Patient and clinical demographics were recorded for all consecutive suspected HF patients over 12months, as well as clinical outcomes including time to HF hospitalisation and time to death (follow up 15.8months).

RESULTS

Of 1995 unselected patients admitted with clinically suspected HF, 1683 (84%) had a NTproBNP over the current NICE recommended threshold, of which 35% received a final diagnosis of HF. Lowering the threshold from 400 to 300pg/ml would have involved screening an additional 61 patients and only would have identified one new patient with HF (sensitivity 0.985, NPV 0.976, area under the curve (AUC) at 300pg/ml 0.67; sensitivity 0.983, NPV 0.977, AUC 0.65 at 400pg/ml). The economic implications of lowering the threshold would have involved additional costs of £42,842.04 (£702.33 per patient screened, or £ 42,824.04 per new HF patient).

CONCLUSION

Applying the recent updated NICE guidelines to an unselected real world population increases the AUC but would have a significant economic impact and only identified one new patient with heart failure.

Cost-Effectiveness Analysis of Natriuretic Peptide Testing and Specialist Management in Patients with Suspected Acute Heart Failure

OBJECTIVES

To determine the cost-effectiveness of natriuretic peptide (NP) testing and specialist outreach in patients with acute heart failure (AHF) residing off the cardiology ward.

METHODS

We used a Markov model to estimate costs and quality-adjusted life-years (QALYs) for patients presenting to hospital with suspected AHF. We examined diagnostic workup with and without the NP test in suspected new cases, and we examined the impact of specialist heart failure outreach in all suspected cases. Inputs for the model were derived from systematic reviews, the UK national heart failure audit, randomized controlled trials, expert consensus from a National Institute for Health and Care Excellence guideline development group, and a national online survey. The main benefit from specialist care (cardiology ward and specialist outreach) was the increased likelihood of discharge on disease-modifying drugs for people with left ventricular systolic dysfunction, which improve mortality and reduce re-admissions due to worsened heart failure (associated with lower utility). Costs included diagnostic investigations, admissions, pharmacological therapy, and follow-up heart failure care.

RESULTS

NP testing and specialist outreach are both higher cost, higher QALY, cost-effective strategies (incremental cost-effectiveness ratios of £11,656 and £2,883 per QALY gained, respectively). Combining NP and specialist outreach is the most cost-effective strategy. This result was robust to both univariate deterministic and probabilistic sensitivity analyses.

CONCLUSIONS

NP testing for the diagnostic workup of new suspected AHF is cost-effective. The use of specialist heart failure outreach for inpatients with AHF residing off the cardiology ward is cost-effective. Both interventions will help improve outcomes for this high-risk group.

Prehospital triage of patients suffering severe dyspnoea using N-terminal pro-brain natriuretic peptide, the PreBNP trial: a randomised controlled clinical trial

PURPOSE

The purpose of this study was to examine whether the addition of brain natriuretic peptide measurement to the routine diagnostic work-up by prehospital critical care team physicians improves triage in patients with severe dyspnoea.

METHODS

Prehospital critical care team physicians randomly assigned patients older than 18 years with severe dyspnoea to routine diagnostic work-up or diagnostic work-up with incorporated point-of-care N-terminal pro-brain natriuretic peptide (NT-proBNP) measurement. The primary endpoint was the proportion of patients with dyspnoea of primary cardiac origin triaged directly to a department of cardiology.

RESULTS

A total of 747 patients were randomly assigned and 711 patients consented to participate, 350 were randomly assigned to the NT-proBNP group and 361 to the routine work-up group. NT-proBNP was measured in 90% (315/350) of patients in the NT-proBNP group and in 19% (70/361) of patients in the routine work-up group. There was no difference in the proportion of patients with dyspnoea of primary cardiac origin triaged directly to a department of cardiology between the NT-proBNP group and the routine work-up group (75% vs. 69%, P=0.22) in the intention-to-treat analysis. Sensitivity analysis according to the de facto diagnostics performed showed results consistent with this. No differences in hospital length of stay, intensive care unit admission rates or mortality between the NT-proBNP group and the routine work-up group were observed.

CONCLUSION

Routine supplementary point-of-care measurement of NT-proBNP in patients with severe dyspnoea did not improve triage of patients with dyspnoea primarily caused by heart disease. ClinicalTrials.gov identifier NCT02050282.

How alternative payment models in emergency medicine can benefit physicians, payers, and patients

While there has been considerable effort devoted to developing alternative payment models (APMs) for primary care physicians and for episodes of care beginning with inpatient admissions, there has been relatively little attention by payers to developing APMs for specialty ambulatory care, and no efforts to develop APMs that explicitly focus on emergency care. In order to ensure that emergency care is appropriately integrated and valued in future payment models, emergency physicians (EPs) must engage with the stakeholders within the broader health care system. In this article, we describe a framework for the development of APMs for emergency medicine and present four examples of APMs that may be applicable in emergency medicine. A better understanding of how APMs can work in emergency medicine will help EPs develop new APMs that improve the cost and quality of care, and leverage the value that emergency care brings to the system.

European Society of Cardiology-Acute Cardiovascular Care Association Position paper on acute heart failure: A call for interdisciplinary care

Acute heart failure (AHF) continues to have unacceptably high rates of mortality and morbidity. This position paper highlights the need for more intense interdisciplinary cooperation as one key element to overcome the challenges associated with fragmentation in the care of AHF patients. Additional aspects discussed include the importance of early diagnosis and treatment, options for initial treatment, referral bias as a potential cause for treatment preferences among experts, considerable uncertainty regarding patient disposition, the diagnosis of accompanying acute myocardial infarction, the need for antibiotic therapy, as well as assessment of intravascular volume status.

How peptide technology has improved costs and outcomes in patients with heart failure

INTRODUCTION

Heart failure (HF) is characterized by substantial health and economic burden, mainly attributed to increased hospitalizations and readmissions. Its diagnosis remains challenging due to the non-specific nature of the initial symptoms of the disease. Recently, scientific evidence has highlighted the potential of natriuretic peptides (NP) in improving the diagnosis and prognosis of HF and, by extension, in restraining healthcare costs. The present review aimed at providing evidence of their optimal use in terms of economic and health outcomes.

AREAS COVERED

Systematic literature research limited to studies published from February 2006 to February 2016 was performed with the aim of identifying and analyzing all cost-effectiveness and other economic evaluation studies that investigated the economic and health outcomes of NPs use as screening and management tools for HF. Expert commentary: NP testing either added in the standard of care, or substituting frequently used diagnostic procedures for the diagnosis and management of HF, regardless of the healthcare setting of interest, was proved to be a valid tool for clinical decision-making. Moreover it was associated with improved patient outcomes and important cost-savings mainly attributed to lower admission and readmission rates, shorter hospitalization length and improved health-related quality of life.

Diagnosing Acute Heart Failure in the Emergency Department: A Systematic Review and Meta-analysis

BACKGROUND

Acute heart failure (AHF) is one of the most common diagnoses assigned to emergency department (ED) patients who are hospitalized. Despite its high prevalence in the emergency setting, the diagnosis of AHF in ED patients with undifferentiated dyspnea can be challenging.

OBJECTIVES

The primary objective of this study was to perform a systematic review and meta-analysis of the operating characteristics of diagnostic elements available to the emergency physician for diagnosing AHF. Secondary objectives were to develop a test-treatment threshold model and to calculate interval likelihood ratios (LRs) for natriuretic peptides (NPs) by pooling patient-level results.

METHODS

PubMed, EMBASE, and selected bibliographies were searched from January 1965 to March 2015 using MeSH terms to address the ability of the following index tests to predict AHF as a cause of dyspnea in adult patients in the ED: history and physical examination, electrocardiogram, chest radiograph (CXR), B-type natriuretic peptide (BNP), N-terminal proB-type natriuretic peptide (NT-proBNP), lung ultrasound (US), bedside echocardiography, and bioimpedance. A diagnosis of AHF based on clinical data combined with objective test results served as the criterion standard diagnosis. Data were analyzed using Meta-DiSc software. Authors of all NP studies were contacted to obtain patient-level data. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2) for systematic reviews was utilized to evaluate the quality and applicability of the studies included.

RESULTS

Based on the included studies, the prevalence of AHF ranged from 29% to 79%. Index tests with pooled positive LRs ≥ 4 were the auscultation of S3 on physical examination (4.0, 95% confidence interval [CI] = 2.7 to 5.9), pulmonary edema on both CXR (4.8, 95% CI = 3.6 to 6.4) and lung US (7.4, 95% CI = 4.2 to 12.8), and reduced ejection fraction observed on bedside echocardiogram (4.1, 95% CI = 2.4 to 7.2). Tests with low negative LRs were BNP < 100 pg/mL (0.11, 95% CI = 0.07 to 0.16), NT-proBNP < 300 pg/mL (0.09, 95% CI = 0.03 to 0.34), and B-line pattern on lung US LR (0.16, 95% CI = 0.05 to 0.51). Interval LRs of BNP concentrations at the low end of "positive" results as defined by a cutoff of 100 pg/mL were substantially lower (100 to 200 pg/mL; 0.29, 95% CI = 0.23 to 0.38) than those associated with higher BNP concentrations (1000 to 1500 pg/mL; 7.12, 95% CI = 4.53 to 11.18). The interval LR of NT-proBNP concentrations even at very high values (30,000 to 200,000 pg/mL) was 3.30 (95% CI = 2.05 to 5.31).

CONCLUSIONS

Bedside lung US and echocardiography appear to the most useful tests for affirming the presence of AHF while NPs are valuable in excluding the diagnosis.

Beyond cardiac troponin: recent advances in the development of alternative biomarkers for cardiovascular disease

Biomarkers complement clinical assessment, electrocardiogram and cardiac imaging in the diagnosis, risk stratification, triage and management of patients with suspected acute cardiovascular diseases. While there is broad consensus that cardiac troponin is the preferred biomarker in clinical practice for the detection of cardiomyocyte damage, the role of alternative biomarkers is less clear. In fact, despite high quality basic and clinical research by hundreds of groups worldwide, only a single new alternative cardiovascular biomarker (natriuretic peptides) has managed to achieve widespread clinical acceptance and inclusion in contemporary clinical practice guidelines in the last decade. This review aims to discuss the remaining unmet needs (and hence opportunities for new biomarkers) in two major clinical areas: early diagnosis of acute myocardial infarction; and early diagnosis and management of acute heart failure, and to evaluate in detail selected alternative biomarkers and recent insights gained from measuring novel biomarkers in large randomized treatment studies in patients with stable coronary artery disease, a setting in which alternative biomarkers may play a more prominent role in the future.

Measurement of natriuretic peptides at the point of care in the emergency and ambulatory setting: current status and future perspectives

The measurement of natriuretic peptides (NPs), B-type NP or N-terminal pro-B-type NP, can be an important tool in the diagnosis of acute heart failure in patients presenting to an Emergency Department (ED) with acute dyspnea, according to international guidelines. Studies and subsequent meta-analyses are mixed on the absolute value of routine NP assessment of ED patients. However, levels of NPs are likely to be used also to guide treatment and to assess risk of adverse outcomes in other patients at risk of developing heart failure, including those with pulmonary embolism or diabetes, or receiving chemotherapy. Natriuretic peptide levels, like other biomarkers, can now be measured at the point of care (POC). We have reviewed the current status of NP measurement together with the potential contribution of POC measurement of NPs to clinical care delivery in the emergency and other settings. Several POC systems for measuring NP levels are now available: these produce test results within 15 minutes and appear sufficiently sensitive and robust to be used routinely in diagnostic evaluations. Point-of-care systems could be used to assess NP levels in the ED and community outpatient settings to monitor the risk of acute heart failure. Furthermore, the use of protocol-driven POC testing of NP within the time frame of a patient consultation in the ED may facilitate and accelerate the throughput and disposition of at-risk patients. Appropriately designed clinical trials will be needed to confirm these potential benefits. It is also important that processes of care delivery are redesigned to take full advantage of the faster turnaround times provided by POC technology.

Determination of a predictive cutoff value of NT-proBNP testing for long-term survival in ED patients with acute heart failure

OBJECTIVE

The main objective of this study was to determine a predictive cutoff value for plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) that could successfully predict the long-term (4-year) survival of patients with acute heart failure (HF) at the time of admission to the emergency department (ED). To our best knowledge, our study is the first research done to identify a predictive cutoff value for admission NT-proBNP to the prescriptive 4-year survival of patients admitted to ED with acute HF diagnosis.

METHODS

NT-proBNP levels were measured in plasma obtained from 99 patients with dyspnea and left ventricular dysfunction upon admission to the ED. The end point was survival from the time of inclusion through 4 years.

RESULTS

The mean age of the patients in this study was 71.1 ± 10.3 years; 50 of these patients were female. During the 4-year follow-up period, 76 patients died; survivors were significantly younger than non-survivors (64.26 ± 11.42 years vs 72.83 ± 11.07 years, P = .002). The optimal NT-proBNP cutoff point for predicting 4-year survival at the time of admission was 2300 pg/mL, which had 85.9% sensitivity and 39.1% specificity (95% confidence interval, area under the curve: 0.639, P = .044).

CONCLUSION

Elevated NT-proBNP levels at the time of admission are a strong and independent predictor of all-cause mortality in patients with acute HF 4 years after admission. Furthermore, the optimal cutoff level of NT-proBNP used to predict 4-year survival had high sensitivity. However, especially in the case of long-term survival, additional prospective, large, and multicenter studies are required to confirm our results.

Natriuretic peptides and NGAL in heart failure: does a link exist?

In recent years there has been growing interest in the development of new diagnostic tools and particularly in laboratory tests for the identification of heart failure (HF) patients. Because of the rise in HF occurrence, it is necessary to use simple and reliable method to recognize those patients at risk before the onset of the clinical symptoms. To date HF diagnosis remains difficult: its symptoms and signs are often non specific as well as being poor sensitive indicators for HF severity. Throughout the last 10 years published literature has highlighted a boom in the use of biomarkers for HF. Both B-type and N-terminal pro-B-type natriuretic peptides have demonstrated specific role in heart failure diagnosis, as well as risk assessment. A single determination of BNP at any time during the development of chronic heart failure (CHF) provides a clinically useful tool to establish the outcome. Renal dysfunction is often associated with heart failure and predicts adverse clinical outcomes. Many studies have recently suggested the clinical use of serum neutrophil gelatinase-associated lipocalin (NGAL) levels in patients admitted to the hospital for acute HF can be used to estimate the risk of early worsening renal function. This could be potentially applied in clinical practice for early identification of renal dysfunction development in patients with HF. NGAL levels appear also to predict renal dysfunction in patients with chronic HF and preserved renal function. For all these reasons, BNP and NGAL are two emerging tools useful for diagnosis and prognosis in HF. The combination of two laboratory biomarkers could potentially identify patients with more elevated risks of both cardiac hemodynamic impairment and kidney dysfunction.

Sublingual tissue perfusion improves during emergency treatment of acute decompensated heart failure

OBJECTIVES

The aim of this study was to measure sublingual perfused capillary density (PCD) to assess sublingual microvascular perfusion during emergency department (ED) treatment of acute decompensated heart failure (ADHF).

METHODS

This prospective, observational study enrolled ED patients with ADHF, measuring pre- and post-ED treatment PCD. Sidestream dark-field imaging was analyzed by 3 investigators blinded to patient identifiers and time points. Patient demographics, ADHF etiology, serum brain natriuretic peptide, and hemoglobin were measured along with a visual analogue scale (VAS), which assessed patient baseline characteristics and response to ED treatment. A paired t test analyzed changes in PCD, mean arterial pressure (MAP), and patient assessment. Interrater variability was assessed with an intraclass correlation coefficient (ICC), with a P value <.05 considered significant for all testing.

RESULTS

Thirty-six patients were enrolled with a mean time between pretreatment and posttreatment PCD (±SD) of 138 ± 59 minutes and a hospital length of stay of 4.0 ± 4.1 days. During this time, PCD increased (difference, 1.3 mm/mm(2); 95% confidence interval, 0.4-2.1; P = .004), as did the MAP (P = .002), patient VAS score (P < .001), and observer VAS score (P < .001). There was no correlation between the change in PCD and time (R(2) = .016, P = .47), MAP (R(2) = .013, P = .54), or VAS scores. The ICC was 0.954.

CONCLUSIONS

Sublingual tissue perfusion is diminished in ADHF but increases with treatment. It may represent a quantitative way to evaluate ADHF in the ED setting.

Brain natriuretic peptide in the evaluation of emergency department dyspnea: is there a role?

BACKGROUND

Acute decompensated congestive heart failure (ADCHF) is a common etiology of dyspnea in emergency department (ED) patients. Delayed diagnosis of ADCHF increases morbidity and mortality. Two cardiac biomarkers, N-terminal-pro brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP) have demonstrated excellent sensitivity in diagnostic accuracy studies, but the clinical impact on patient-oriented outcomes of these tests remains in question.

CLINICAL QUESTION

Does emergency physician awareness of BNP or NT-proBNP level improve ADCHF patient-important outcomes including ED length of stay, hospital length of stay, cardiovascular mortality, or overall health care costs?

EVIDENCE REVIEW

Five trials have randomized clinicians to either knowledge of or no knowledge of ADCHF biomarker levels in ED patients with dyspnea and some suspicion for heart failure. In assessing patient-oriented outcomes such as length-of-stay, return visits, and overall health care costs, the randomized controlled trials fail to provide evidence of unequivocal benefit to patients, clinicians, or society.

CONCLUSION

Clinician awareness of BNP or NT-proBNP levels in ED dyspnea patients does not necessarily improve outcomes. Future ADCHF biomarker trials must assess patient-oriented outcomes in conjunction with validated risk-stratification instruments.

The Relationship between Serum NT- Pro-BNP Levels and Prognosis in Patients with Systolic Heart Failure

INTRODUCTION

Most studies reported using N-terminal pro-brain natriuretic peptide (NT-proBNP) in diagnosis of heart failure but there is controversy about use of these tests in determining prognosis and classification of severity of heart failure. The objective of this study was to determine the value of plasma NT-proBNP levels assessment in evaluation of mortality and morbidity of patients with systolic left ventricular dysfunction.

METHODS

A cohort study was performed in 150 patients with heart failure since September 2009 until February 2010. The patients were followed for 6 months to assess their prognosis. Patients were divided into two good and bad prognosis groups according to severity of heart failure in New York Heart Association (NYHA) class and frequency of hospital admission and mortality due to cardiac causes. Patients with good prognosis had ≥1 admission or no mortality or NYHA class ≥2 and patients that had one of this criteria considered as bad prognosis groups. Pro-BNP levels were measured at baseline and left ventricular ejection fraction (LVEF) was estimated with echocardiography. Data was analyzed with using Chi-square, t-test, ANOVA, Kruskal-Wallis tests.

RESULTS

In patients with heart failure that enrolled in this clinical study, ten patients were lost during follow-up. The mean of NT-proBNP is significantly correlated with ejection fraction (p=0.003) and NYHA class (p<0.001). In our study among 140 patients who were follow-up for 6 months, 11(9.7%) of individuals died with mean NT-proBNP of 8994.8±8375 pg/ml, in survived patients mean NT-proBNP was 3756.8±5645.6 pg/ml that was statistically significant (P=0.02). Mean NT-proBNP in the group with good prognosis was 2723.8±4845.2 pg/ml and in the group with bad prognosis was 5420.3±6681 pg/ml, difference was statistically significant (P=0.0001).

CONCLUSION

Our study in consistent with other studies confirms that NT-proBNP is significantly correlated with mortality and morbidity. This could be predicting adverse out come and stratification in patients with heart failure. It is recommended that more research be performed in Iran.

Telomere dynamics unique to meiotic prophase: formation and significance of the bouquet

Telomeres carry out conserved and possibly ancient functions in meiosis. During the specialized prophase of meiosis I, meiotic prophase, telomeres cluster on the nuclear envelope and move the diploid genetic material around within the nucleus so that homologous chromosomes can align two by two and efficiently recombine with precision. This recombination is in turn required for proper segregation of the homologs into viable haploid daughter cells. The meiosis-specific telomere clustering on the nuclear envelope defines the bouquet stage, so named for its resemblance to the stems from a bouquet of cut flowers. Here, a comparative analysis of the literature on meiotic telomeres from a variety of different species illustrates that the bouquet is nearly universal among life cycles with sexual reproduction. The bouquet has been well documented for over 100 years, but our understanding of how it forms and how it functions has only recently begun to increase. Early and recent observations document the timing and provide clues about the functional significance of these striking telomere movements.