title: Utility of B-type natriuretic peptide in the diagnosis of congestive heart failure in an urgent-care setting.
abstract: OBJECTIVE
  The goal of this study was to evaluate the utility of a rapid "bedside" technique for measurement of B-type natriuretic peptide (BNP) in the diagnosis of congestive heart failure (CHF) in an urgent-care setting.
  
  
  BACKGROUND
  B-type natriuretic peptide is a protein secreted from the cardiac ventricles in response to pressure overload. One potential application of measurements of BNP in blood is distinguishing dyspnea due to CHF from other causes.
  
  
  METHODS
  B-type natriuretic peptide concentrations were measured in a convenience sample of 250 predominantly male (94%) patients presenting to urgent-care and emergency departments of an academic Veteran's Affairs hospital with dyspnea. Results were withheld from clinicians. Two cardiologists retrospectively reviewed clinical data (blinded to BNP measurements) and reached a consensus opinion on the cause of the patient's symptoms. This gold standard was used to evaluate the diagnostic performance of the BNP test.
  
  
  RESULTS
  The mean BNP concentration in the blood of patients with CHF (n = 97) was higher than it was in patients without (1,076 +/- 138 pg/ml vs. 38 +/- 4 pg/ml, p < 0.001). At a blood concentration of 80 pg/ml, BNP was an accurate predictor of the presence of CHF (95%); measurements less than this had a high negative predictive value (98%). The overall C-statistic was 0.97. In multivariate analysis, BNP measurements added significant, independent explanatory power to other clinical variables in models predicting which patients had CHF. The availability of BNP measurements could have potentially corrected 29 of the 30 diagnoses missed by urgent-care physicians.
  
  
  CONCLUSIONS
  B-type natriuretic peptide blood concentration measurement appears to be a sensitive and specific test to diagnose CHF in urgent-care settings.
authors.affiliation: Department of Medicine, Veteran's Affairs Medical Center, San Diego, California, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Dao
authors.forename: P
authors.initials: P
authors.lastname: Krishnaswamy
authors.forename: R
authors.initials: R
authors.lastname: Kazanegra
authors.forename: A
authors.initials: A
authors.lastname: Harrison
authors.forename: R
authors.initials: R
authors.lastname: Amirnovin
authors.forename: L
authors.initials: L
authors.lastname: Lenert
authors.forename: P
authors.initials: P
authors.lastname: Clopton
authors.forename: J
authors.initials: J
authors.lastname: Alberto
authors.forename: P
authors.initials: P
authors.lastname: Hlavin
authors.forename: A S
authors.initials: AS
authors.lastname: Maisel
mesh_terms: D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood*; D002140:California; D004636:Emergency Service, Hospital; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006787:Hospitals, Veterans; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain; D011237:Predictive Value of Tests
chemical_list: D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor