***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: Measurement of B-type natriuretic peptide ( BNP )  has been shown to aid in the Emergency Department ( ED ) diagnosis of heart failure . We sought to determine how point-of-care BNP measurement influences real-world medical decision-making . Using a commercially available , point-of-care assay ,  BNP levels were measured in a convenience sample of ED patients over the age of 55 years who complained of dyspnea . Blinded to BNP results , emergency physicians were asked to formulate a differential diagnosis and management plan for each patient . Immediately thereafter , BNP results were disclosed and the physicians were asked what ( if any ) decisions they would change . With physicians blinded to BNP results , 24 of 88 patients ( 27 % ) were given a primary diagnosis of heart failure , and 18 patients ( 20 % ) were given a secondary or alternative diagnosis of heart failure . For the former group , disclosure of BNP results result ed in no changes in diagnosis or management . For the latter group , disclosure of BNP results caused heart failure to become the primary diagnosis in 4 patients ( 22 % ) , and led to five changes in medical management . For the 46 patients initially given neither a primary nor secondary diagnosis of heart failure , disclosure of BNP results caused heart failure to become the primary diagnosis in one patient ( 2 % ) and a secondary diagnosis in 4 patients ( 9 % ) , and led to five changes in medical management . Thus , for ED patients with a primary clinical diagnosis of heart failure , BNP testing had no impact on medical decision-making . However , for other patients with dyspnea , elevated BNP levels did influence medical decision-making , particularly when heart failure was in the differential diagnosis BACKGROUND B-type natriuretic peptide is released from the cardiac ventricles in response to increased wall tension . METHODS We conducted a prospect i ve study of 1586 patients who came to the emergency department with acute dyspnea and whose B-type natriuretic peptide was measured with a bedside assay .  The clinical diagnosis of congestive heart failure was adjudicated by two independent cardiologists , who were blinded to the results of the B-type natriuretic peptide assay . RESULTS The final diagnosis was dyspnea due to congestive heart failure in 744 patients ( 47 percent ) , dyspnea due to noncardiac causes in 72 patients with a history of left ventricular dysfunction ( 5 percent ) , and no finding of congestive heart failure in 770 patients ( 49 percent ) .  B-type natriuretic peptide levels by themselves were more accurate than any historical or physical findings or laboratory values in identifying congestive heart failure as the cause of dyspnea . The diagnostic accuracy of B-type natriuretic peptide at a cutoff of 100 pg per milliliter was 83.4 percent . The negative predictive value of B-type natriuretic peptide at levels of less than 50 pg per milliliter was 96 percent . In multiple logistic-regression analysis , measurements of B-type natriuretic peptide added significant independent predictive power to other clinical variables in models predicting which patients had congestive heart failure . CONCLUSIONS Used in conjunction with other clinical information , rapid measurement of B-type natriuretic peptide is useful in establishing or excluding the diagnosis of congestive heart failure in patients with acute dyspnea BACKGROUND Amino-terminal pro-brain natriuretic peptide ( NT-proBNP ) is useful for diagnosis and triage of patients with dyspnea , but its role for predicting outcomes in such patients remains undefined . METHODS A total of 599 breathless patients treated in the emergency department were prospect ively enrolled , and a sample of blood was obtained for NT-proBNP measurements . After 1 year , the vital status of each patient was ascertained , and the association between NT-proBNP values at presentation and mortality was assessed . RESULTS At 1 year , 91 patients ( 15.2 % ) had died . Median NT-proBNP concentrations at presentation among decedents were significantly higher than those of survivors ( 3277 vs 299 pg/mL ; P<.001 ) . The optimal NT-proBNP cut point for predicting 1-year mortality was 986 pg/mL. In a multivariable model , an NT-proBNP concentration greater than 986 pg/mL at presentation was the single strongest predictor of death at 1 year ( hazard ratio [ HR ] , 2.88 ; 95 % confidence interval , 1.64 - 5.06 ; P<.001 ) , independent of a diagnosis of heart failure . Other factors associated with death included age ( by decade ; HR , 1.20 ) , heart rate ( by decile ; HR , 1.13 ) , urea nitrogen level ( by decile ; HR , 1.20 ) , systolic blood pressure less than 100 mm Hg ( HR , 1.94 ) , heart murmur ( HR , 1.92 ) , and New York Heart Association classification ( HR , 1.38 for each increase in class ) . The NT-proBNP concentration alone had an area under the receiver operating characteristic curve ( AUC ) of 0.76 for predicting mortality ; the other significant covariates combined had an AUC of 0.80 . The final model for predicting death , combining NT-proBNP with other covariates associated with mortality , had a superior AUC of 0.82 . CONCLUSION In addition to assisting in emergency department diagnosis and triage , NT-proBNP concentrations at presentation are strongly predictive of 1-year mortality in dyspneic patients Background —B-type natriuretic peptide is useful to diagnose heart failure . We determined whether the use of serial B-type natriuretic peptide measurements to guide treatment improves the outcome in patients with acute heart failure . Methods and Results —We conducted a r and omized controlled trial of patients with acute heart failure in 10 academic and community emergency departments . The experimental group received serial B-type natriuretic peptide testing ( at 3 , 6 , 9 , and 12 hours then daily ) . The control group received usual care . Our outcomes were hospital length of stay , 30-day readmission rate , and all-cause mortality . There were 219 controls and 228 experimental patients . Mean age was 64 years , 49 % were women , 58 % were blacks , and 34 % were whites . Groups were similar in baseline characteristics . Comparing the serial testing with the control group , there was no difference in length of stay ( 6.5 days [ 95 % CI , 5.2 to 7.9 ] versus 6.5 days [ 95 % CI , 5.6 to 7.3 ] ; difference , 0.1 [ 95 % CI , −1.7 to 1.5 ] ) , in-hospital mortality ( 2.2 % [ 95 % CI , 0.9 to 5.0 ] versus controls , 3.2 % [ 95 % CI , 1.6 to 6.5 ] ; difference , 1.0 % [ 95 % CI , −2.3 to 4.5 ] ) , 30-day mortality ( 3.7 % [ 95 % CI , 1.8 to 7.5 ] versus 5.5 % [ 95 % CI , 3.0 to 9.8 ] ; difference , 1.8 % [ 95 % CI , −2.8 to 6.5 ] ) , or hospital revisit rate ( 20.2 % [ 95 % CI , 15.0 to 26.6 ] versus 23.7 % [ 95 % CI , 18.0 to 30.6 ] ; difference , 3.5 % [ 95 % CI , −5.1 to 12.1 ] ) . Conclusions —In this study of 447 patients hospitalized for suspected heart failure , we were unable to demonstrate a benefit of serial testing with B-type natriuretic peptide in terms of hospital length of stay , mortality , or readmission rate STUDY OBJECTIVE B-Type natriuretic peptide ( BNP ) is a neurohormone secreted from the cardiac ventricles in response to volume expansion and pressure overload . We have recently demonstrated that BNP can differentiate congestive heart failure ( CHF ) from other causes of dyspnea in patients presenting to the emergency department . In this study , we assess whether BNP levels drawn in patients presenting with dyspnea to the ED were a predictor of future cardiac events . METHODS In 325 patients presenting with dyspnea to the ED , BNP levels were determined . Patients were then followed up for 6 months to determine the following end points : death ( cardiac and noncardiac ) , hospital admissions ( cardiac ) , and repeat ED visits for CHF . Receiver operating characteristic ( ROC ) curves , relative risks ( RRs ) , and Kaplan-Meier plots were used to assess the ability of BNP levels to predict future cardiac events . RESULTS The area under the ROC curve using BNP to detect a CHF end point-a CHF death , hospital admission , or repeat ED visit-was 0.870 ( 95 % confidence interval [ CI ] 0.826 to 0.915 ) . A BNP value of 480 pg/mL had a sensitivity of 68 % , specificity of 88 % , and an accuracy of 85 % for predicting a subsequent CHF end point . The area under the ROC curve using BNP to detect death from CHF was 0.881 ( 95 % CI 0.807 to 0.954 ) and for any cardiac death was 0.877 ( 95 % CI 0.822 to 0.933 ) . BNP was not associated with death from noncardiac causes . Using Kaplan-Meier plots for all CHF events , rising BNP levels were associated with a progressively worse prognosis . Patients with BNP levels more than 480 pg/mL had a 51 % 6-month cumulative probability of a CHF event . Alternatively , patients with BNP levels less than 230 pg/mL had an excellent prognosis with only 2.5 % incidence of CHF end points . The RR of 6-month CHF death in patients with BNP levels more than 230 pg/mL was 24.1 . The RR of 6-month noncardiac death with BNP levels more than 230 pg/mL was 1.1 . BNP levels were also predictive of CHF events in subsets of patients with positive CHF histories and ED diagnoses . CONCLUSION In this study population , BNP levels measured in patients presenting with dyspnea to the ED are highly predictive of cardiac events over the next 6 months BACKGROUND Both  B-type natriuretic peptide ( BNP )  and renal function are prognostic indicators of survival in patients with congestive heart failure ( CHF ) . However , relationships between BNP , renal function , and heart failure as an emergency diagnosis are unknown . METHODS The Breathing Not Properly Multinational Study was a prospect ively design ed diagnostic test evaluation study conducted in seven centers . Of 1,586 participants who presented with acute dyspnea , 1,452 patients ( 91.6 % ) had both BNP level and baseline estimated glomerular filtration rate ( eGFR ) available . Patients with an eGFR less than 15 mL/min/1.73 m2 and those on dialysis therapy were excluded . The final diagnosis was adjudicated by two independent cardiologists who were blinded to BNP results . RESULTS The final diagnosis was CHF in 715 patients ( 49.2 % ) . Raw and log-log transformed correlations between BNP and eGFR values were r = -0.19 and r = -0.17 for those with CHF and r = -0.20 and r = -0.31 for those without CHF ( both P < 0.0001 for r not equal 0 ) . Mean BNP levels were 561.6 pg/mL ( 162.3 fmol/mL ) , 647.5 pg/mL ( 187.1 fmol/mL ) , 745.6 pg/mL ( 215.5 fmol/mL ) , and 850.7 pg/mL ( 245.8 fmol/mL ) for those with CHF and 85.4 pg/mL ( 24.7 fmol/mL ) , 131.7 pg/mL ( 38.1 fmol/mL ) , 297.2 pg/mL ( 85.9 fmol/mL ) , and 285.0 pg/mL ( 82.3 fmol/mL ) for those without CHF in eGFR categories of 90 or greater , 89 to 60 , 59 to 30 , and less than 30 mL/min/1.73 m2 , respectively . The area under the receiver operating characteristic curve and optimum cut points for BNP were 0.91 and 70.7 pg/mL ( 20.4 fmol/mL ) , 0.90 and 104.3 pg/mL ( 30.1 fmol/mL ) , 0.81 and 201.2 pg/mL ( 58.1 fmol/mL ) , and 0.86 and 225.0 pg/mL ( 65.0 fmol/mL ) for the eGFR categories of 90 or greater , 89 to 60 , 59 to 30 , and less than 30 mL/min/1.73 m2 , respectively . CONCLUSION Renal function correl 
    Output:
    
CONCLUSION B-type natriuretic peptide testing in the emergency department for patients presenting with acute dyspnea decreased length hospital of stay by about 1 day and possibly reduced admission rates but did not conclusively affect hospital mortality rates .