***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Objective : To investigate the performance of a novel assay for N-terminal pro-brain natriuretic peptide ( NT-proBNP ) in diagnosing heart failure in various r and omly selected general and high risk community population s. Design : Community cohort study ( sub study of the echocardiographic heart of Engl and screening study ) . Setting : Four r and omly selected general practice s in the West Midl and s of Engl and . Participants : 591 r and omly sample d patients over the age of 45 , stratified for age and socioeconomic status and falling into four cohorts ( general population , patients with an existing clinical label of heart failure , patients prescribed diuretics , and patients deemed at high risk of heart failure ) . Main outcome measure : Sensitivity , specificity , positive and negative predictive values , likelihood ratios , and area under receiver operating characteristic curve for NT-proBNP assay  in the diagnosis of heart failure . Results : For NT-proBNP in the diagnosis of heart failure in the general population ( population screen ) , a level of > 36 pmol/l had a sensitivity of 100 % , a specificity of 70 % , a positive predictive value of 7 % , a negative predictive value of 100 % , and an area under the receiver operating characteristic curve of 0.92 ( 95 % confidence interval 0.82 to 1.0 ) . Similar negative predictive values were found for patients from the three other population s screened . Conclusions : This NT-proBNP assay seems to have value in the diagnosis of heart failure in the community . High negative predictive values indicate that the assay 's chief use would be to rule out heart failure in patients with suspected heart failure with normal concentrations of NT-proBNP . Positive results may identify patients who need cardiac imaging CONTEXT Several reports have suggested the usefulness of plasma brain natriuretic peptide ( BNP ) as a screening test for left ventricular hypertrophy ( LVH ) and systolic dysfunction ( LVSD ) . Prior studies were limited by small sample sizes and selection bias and none compared the diagnostic performance of these peptides in men and women . OBJECTIVES To examine the usefulness of natriuretic peptides for screening for elevated LV mass and LVSD in the community . DESIGN , SETTING , AND PARTICIPANTS Community-based prospect i ve cohort study of 3177 participants ( 1707 women ) from the Framingham Study who attended a routine examination in 1995 - 1998 . MAIN OUTCOME MEASURES Receiver operating characteristic ( ROC ) curves , test sensitivity , specificity , positive and negative predictive values , and likelihood ratios for identifying elevated LV mass ( sex-specific 90th percentile or higher of LV mass/[height](2 ) ) , LVSD ( ejection fraction < or = 50 % and /or fractional shortening < 29 % ) , and moderate to severe LVSD ( ejection fraction < or = 40 % and /or fractional shortening < 22 % ) at different discrimination limits of plasma BNP and N-terminal proatrial natriuretic peptide ( NT-ANP ) , with echocardiography as the criterion st and ard . RESULTS The areas under the ROC curves for elevated LV mass or LVSD were at or below 0.75 for both peptides , were higher for men compared with women , and were similar for BNP and NT-ANP . The diagnostic performance of natriuretic peptides for LVSD improved in women but not in men when select high-risk subgroups were targeted . Discrimination limits based on high specificity ( 0.95 ) yielded better positive predictive values and likelihood ratios compared with age- and sex-specific reference limits yet only identified less than one third of participants who had elevated LV mass or LVSD . CONCLUSION In our large community-based sample , the performance of BNP and NT-ANP for detection of elevated LV mass and LVSD was suboptimal , suggesting limited usefulness of natriuretic peptides as mass screening tools BACKGROUND The aim of the study was to prospect ively evaluate patients with suspected or known heart disease using plasma brain natriuretic peptide ( BNP ) measurement and radionuclide ventriculography to examine whether left ventricular dysfunction is associated with an abnormal rise of BNP concentration . METHODS Patients ( n=153 ) and controls ( n=14 ) underwent radionuclide ventriculography to determine Left ventricular Ejection Fraction ( LVEF ) and measurement of plasma BNP concentration using a commercial kit . RESULTS Plasma BNP concentration in controls was significantly lower than that in patients whatever the stage of the disease , significantly lower than that of patients with normal LVEF ( LVEF>55 % ) ; than that of patients with altered LVEF ( LVEF < or = 40 % ) ; and than that of patients with moderately reduced LVEF ( 40%<LVEF < or = 5 % ) . Comparisons between groups of patients showed that the more severe the disease , the higher the BNP level . From the ROC curve , a plasma BNP concentration of 52 pg/ml was attached to a 85 % sensitivity and 82 % specificity in identifying patients with LVEF < or = 40 % . CONCLUSIONS Plasma BNP concentration provides a reliable and sensitive marker of LV systolic dysfunction evaluated by a nuclear medicine technique , and could be a potential screening test to identify patients for additional investigations 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 In previous studies on the use of natriuretic peptides to detect left-ventricular systolic dysfunction , a higher rate of cardiac disorders in the control groups than in the study groups could have led to bias . We investigated the effectiveness of plasma N-terminal atrial natriuretic peptide ( NT-ANP ) and brain natriuretic peptide ( BNP ) concentrations to show left-ventricular systolic dysfunction in a r and om sample of the general population . METHODS We r and omly selected 2000 participants aged 25 - 74 years from family physicians ' lists in Glasgow , UK . We sent all participants question naires . 1653 respondents underwent echocardiography and electrocardiography .  We took a left-ventricular ejection fraction of 30 % or less to show left-ventricular systolic dysfunction . NT-ANP and BNP were measured in plasma by RIAs . FINDINGS 1252 participants had analysable electrocardiograms and echocardiograms , completed question naires , and available blood sample s. Median concentrations of NT-ANP and BNP were significantly higher in participants with left-ventricular systolic dysfunction ( 2.8 ng/mL [ IQR 1.8 - 4.6 ] and 24.0 pg/mL [ 18.0 - 33.0 ] ) than in those without ( 1.3 ng/mL [ 0.9 - 1.8 ] and 7.7 pg/mL [ 3.4 - 13.0 ] ; each p < 0.001 ) . Among participants with left-ventricular systolic dysfunction , both symptomatic and asymptomatic subgroups had raised NT-ANP and BNP concentrations . A BNP concentration of 17.9 pg/mL or more gave a sensitivity of 77 % and specificity of 87 % in all participants , and 92 % and 72 % in participants aged 55 years or older . INTERPRETATION Measurement of BNP could be a cost-effective method of screening for left-ventricular systolic dysfunction in the general population , especially if its use were targeted to individuals at high risk BACKGROUND In the studies of left ventricular dysfunction ( SOLVD ) , enalapril reduced mortality in patients with symptomatic but not asymptomatic left ventricular systolic dysfunction during the trial . We did a 12-year follow-up of SOLVD to establish if the mortality reduction with enalapril among patients with heart failure was sustained , and whether a subsequent reduction in mortality would emerge among those with asymptomatic ventricular dysfunction . METHODS Of the 6797 patients previously enrolled in the SOLVD prevention and treatment trials , we ascertained the subsequent vital status of 5165 individuals who were alive when the trials had been completed . Follow-up was done through direct contacts in Belgium and linkages with national death registries and federal beneficiary or historic tax summary files in the USA and Canada . FINDINGS Follow-up was 99.8 % ( 6784/6797 ) complete . In the prevention trial , 50.9 % ( 1074/2111 ) of the enalapril group had died compared with 56.4 % ( 1195/2117 ) of the placebo group ( generalised Wilcoxon p=0.001 ) . In the treatment trial , 79.8 % ( 1025/1285 ) of the enalapril group had died compared with 80.8 % ( 1038/1284 ) of the placebo group ( generalised Wilcoxon p=0.01 ) . The reductions in cardiac deaths were significant and similar in both trials . When data for the prevention and treatment trials were combined , the hazard ratio for death was 0.90 for the enalapril group compared with the placebo group ( 95 % CI 0.84 - 0.95 , generalised Wilcoxon p=0.0003 ) . Enalapril extended median survival by 9.4 months in the combined trials ( 95 % CI 2.8 - 16.5 , p=0.004 ) . INTERPRETATION Treatment with enalapril for 3 - 4 years led to a sustained improvement in survival beyond the original trial period in patients with left ventricular systolic dysfunction , with an important increase in life expectancy BACKGROUND The reliability of a clinical diagnosis of heart failure in primary care is poor . Concentrations of natriuretic peptides are high in heart failure . This population -based study examined the predictive value of natriuretic peptides in patients with a new primary -care diagnosis of heart failure . METHODS Concentrations of plasma atrial ( ANP and N-terminal ANP ) and B-type ( BNP ) natriuretic peptides were measured by radioimmunoassay in 122 consecutive patients referred to a rapid-access heart-failure clinic with a new primary -care diagnosis of heart failure . On the basis of clinical assessment , chest radiography , and transthoracic echocardiography , a panel of three cardiologists decided that 35 ( 29 % ) patients met the case definition for new heart failure . ANP and NT-ANP results were available for 117 patients ( 34 with heart failure ) and BNP results for 106 ( 29 with heart failure ) . FINDINGS Geometric mean concentrations of natriuretic peptides were much higher in patients with heart failure than in those with other diagnoses ( 29.2 vs 12.4 pmol/L for ANP ; 63.9 vs 13.9 pmol/L for BNP ; 1187 vs 410.6 pmol/L for NT-ANP ; all p < 0.001 ) . At cut-off values chosen to give negative predictive values for heart failure of 98 % ( ANP > or = 18.1 pmol/L , NT-ANP > or = 537.6 pmol/L , BNP > or = 22.2 pmol/L ) , the sensitivity , specificity , and positive predictive value for ANP were 97 % , 72 % , and 55 % ; for NT-ANP 97 % , 66 % , and 54 % ; and for BNP 97 % , 84 % , and 70 % . Addition of ANP or NT-ANP concentration or both did not improve the predictive power of a logistic regression model containing BNP concentration alone . INTERPRETATION In patients with symptoms suspected by a general practitioner to be due to heart failure 
    Output:
    
The use of BNP tests to rule out CHF in primary care setting s could reduce dem and for echocardiography .