title: Utility of B-natriuretic peptide levels in identifying patients with left ventricular systolic or diastolic dysfunction.
abstract: OBJECTIVE
  Although echocardiography is important for making the diagnosis of left ventricular dysfunction, its cost and lack of availability limit its use as a routine screening test. B-Natriuretic peptide levels accurately reflect ventricular pressure, and preliminary studies with a rapid assay have found that levels are sensitive and specific for diagnosing heart failure in patients with dyspnea. We hypothesized that B-natriuretic peptide levels obtained through the use of a rapid assay should correlate with echocardiographic abnormalities of ventricular function.
  
  
  METHODS
  We studied 400 patients who were referred for echocardiography at the San Diego Veteran's Healthcare System between June and August 2000 to evaluate ventricular function. B-natriuretic peptide levels were measured by a point-of-care immunoassay; cardiologists assessing left ventricular function were blinded to the assay results. Patients were grouped into those with normal ventricular function, systolic dysfunction only, diastolic dysfunction only, and both systolic and diastolic dysfunction.
  
  
  RESULTS
  Mean (+/- SD) B-natriuretic peptide concentration was 416 +/- 413 pg/mL in the 253 patients diagnosed with abnormal left ventricular function, compared with 30 +/- 36 pg/mL in the 147 patients with normal left ventricular function. Patients with both systolic and diastolic dysfunction had the highest levels (675 +/- 423 pg/mL). The area under the receiver operating characteristic (ROC) curve for B-natriuretic peptide levels to detect any abnormal echocardiographic finding was 0.95 (91% confidence interval: 0.93 to 0.97). B-Natriuretic peptide levels were unable to differentiate systolic vs. diastolic dysfunction. In patients with symptoms of heart failure and normal systolic function, B-natriuretic peptide levels >57 pg/mL had a positive predictive value of 100% for diastolic abnormalities.
  
  
  CONCLUSIONS
  A simple, rapid test for B-natriuretic peptide levels can reliably predict the presence or absence of left ventricular dysfunction on echocardiogram. For some patients, a normal level may preclude the need for echocardiography.
authors.affiliation: Division of Cardiology, Department of Medicine, Veteran's Affairs Medical Center, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
authors.forename: P
authors.initials: P
authors.lastname: Krishnaswamy
authors.forename: E
authors.initials: E
authors.lastname: Lubien
authors.forename: P
authors.initials: P
authors.lastname: Clopton
authors.forename: J
authors.initials: J
authors.lastname: Koon
authors.forename: R
authors.initials: R
authors.lastname: Kazanegra
authors.forename: E
authors.initials: E
authors.lastname: Wanner
authors.forename: N
authors.initials: N
authors.lastname: Gardetto
authors.forename: A
authors.initials: A
authors.lastname: Garcia
authors.forename: A
authors.initials: A
authors.lastname: DeMaria
authors.forename: A S
authors.initials: AS
authors.lastname: Maisel
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D009320:Atrial Natriuretic Factor / Q000097:blood; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: D009320:Atrial Natriuretic Factor