Cut-off values of B-type natriuretic peptide for the diagnosis of congestive heart failure in patients with dyspnoea visiting emergency departments: a study on Korean patients visiting emergency departments

Accuracy of B-type natriuretic peptide in a multiethnic Asian population with acute dyspnea

Background:

Optimal cut-offs for B-type natriuretic peptide (BNP) for the diagnosis of heart failure differ based on ethnicity. There are no data for Southeast Asian patients. We aimed to define the optimal cut-off points and the strength of B-type natriuretic peptide as a predictor of heart failure in Southeast Asian multiethnic population.

Methods:

Bedside B-type natriuretic peptide (SOB panel (Biosite®)) was measured for patients (>50 years) presenting with dyspnea. Emergency physicians (blinded to B-type natriuretic peptide result) assessed the probability of acute heart failure on a scale of 0%–100%. Heart failure diagnosis was adjudicated by two cardiologists.

Results:

In all, 43% (n = 87) of the 203 dyspneic patients (54.7% males, 453% females) had a final diagnosis of acute heart failure. B-type natriuretic peptide values ranged from 3.2 to 4960 pg/mL (median, 189 pg/mL). Median B-type natriuretic peptide values of patients with the final diagnosis of “acute heart failure,” “no acute heart failure but history of heart failure,” and “no heart failure” were 600, 301, and 68 pg/mL, respectively. The optimum cut-off was 186 pg/mL. The receiver operating characteristic curve of the emergency physician’s assessment of the probability of heart failure based on clinical assessment had an area under the curve of 85% (95% confidence interval: 80%–90%). Combining receiver operating characteristic curves of physician assessment and B-type natriuretic peptide values yielded an area under the curve of 96% (95% confidence interval: 93%–98%). B-type natriuretic peptide levels less than 100 pg/mL were the strongest predictor of heart failure (odds ratio: 26.36; confidence interval: 6.85–101.41), followed by upper lobe diversion and cardiomegaly.

Conclusion:

The accuracy of bedside B-type natriuretic peptide was validated in a multiethnic Asian population. Optimum cut-off is 186 pg/mL. A B-type natriuretic peptide >100 pg/mL is the single strongest independent predictor of heart failure.

SOMAscan-based proteomic measurements of plasma brain natriuretic peptide are decreased in mild cognitive impairment and in Alzheimer's dementia patients

Alzheimer's disease represents the most common age-related neurodegenerative disorder and a leading cause of progressive cognitive impairment. Predicting cognitive decline is challenging but would be invaluable in an increasingly aging population which also experiences a rising cardiovascular risk. In order to examine whether plasma measurements of one of the established biomarkers of heart failure, brain natriuretic peptide (BNP), reflect a decline in cognitive function, associated with Alzheimer's disease neurodegeneration, BNP levels were analysed, by using a novel assay called a SOMAscan, in 1. cognitively healthy, control subjects; 2. subjects with mild cognitive impairment, and 3. subjects with Alzheimer's disease. The results of our study show that the levels of the BNP were significantly different between the three types of diagnoses (p < 0.05), whereby subjects with mild cognitive impairment had the lowest mean BNP value, and healthy subjects had the highest BNP value. Importantly, our results show that the levels of the BNP are influenced by the presence of at least one APOE4 allele in the healthy (p < 0.05) and in the Alzheimer's disease groups of subjects (p < 0.1). As the levels of the BNP appear to be independent of the APOE4 genotype in subjects with mild cognitive impairment, the results of our study support inclusion of measurements of plasma levels of the BNP in the list of the core Alzheimer's disease biomarkers for identification of the mild cognitive impairment group of patients. In addition, the results of our study warrant further investigations into molecular links between Alzheimer's disease-type cognitive decline and cardiovascular disorders.

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.

Performance of BNP and NT-proBNP for diagnosis of heart failure in primary care patients: a systematic review

National and international guidelines have been published recommending the use of natriuretic peptides as an aid to the diagnosis of heart failure (HF) in acute settings; however, few specific recommendations exist for governing the use of these peptides in primary care populations. To summarize the available data relevant to the diagnosis of HF in primary care patient population, we systematically reviewed the literature to identify original articles that investigated the diagnostic accuracy of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in primary care settings. The search yielded 25,864 articles in total: 12 investigating BNP and 20 investigating NT-proBNP were relevant to our objective and included in the review. QUADAS-2 and GRADE were used to assess the quality of the included articles. Diagnostic data were pooled based on three cutpoints: lowest and optimal, as chosen by study authors, and manufacturers' suggested. The effect of various determinants (e.g., age, gender, BMI, and renal function) on diagnostic performance was also investigated. Pooled sensitivity and specificity of BNP and NT-proBNP using the lowest [0.85 (sensitivity) and 0.54 (specificity)], optimal (0.80 and 0.61), and manufacturers' (0.74 and 0.67) cutpoints showed good performance for diagnosing HF. Similar performance was seen for NT-proBNP: lowest (0.90 and 0.50), optimal (0.86 and 0.58), and manufacturers' (0.82 and 0.58) cutpoints. Overall, we rated the strength of evidence as high because further studies will be unlikely to change the estimates diagnostic performance.

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.