title: Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care.
abstract: BACKGROUND
  Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate.
  
  
  METHODS
  N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical information, and echocardiographic data of left ventricular systolic function were collected in 542 family practice patients with at least one cardiovascular risk factor. We determined the diagnostic power of the NT-proBNP assessment in ruling out left ventricular systolic dysfunction and compared it to a risk score derived from a logistic regression model of easily acquired clinical information.
  
  
  RESULTS
  23 of 542 patients showed left ventricular systolic dysfunction. Both NT-proBNP and the clinical risk score consisting of dyspnea at exertion and ankle swelling, coronary artery disease and diuretic treatment showed excellent diagnostic power for ruling out left ventricular systolic dysfunction. AUC of NT-proBNP was 0.83 (95% CI, 0.75 to 0.92) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.46 (95% CI, 0.41 to 0.50). AUC of the clinical risk score was 0.85 (95% CI, 0.79 to 0.91) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.64 (95% CI, 0.59 to 0.67). 148 misclassifications using NT-proBNP and 55 using the clinical risk score revealed a significant difference (McNemar test; p < 0.001) that was based on the higher specificity of the clinical risk score.
  
  
  CONCLUSIONS
  The evaluation of clinical information is at least as effective as NT-proBNP testing in ruling out left ventricular systolic dysfunction in family practice patients at risk. If these results are confirmed in larger cohorts and in different samples, family physicians should be encouraged to rely on the diagnostic power of the clinical information from their patients.
authors.affiliation: Department of General Practice, Georg-August-University Göttingen, Germany. jkoscha@gwdg.de
authors.forename: Janka
authors.initials: J
authors.lastname: Koschack
authors.forename: Martin
authors.initials: M
authors.lastname: Scherer
authors.forename: Claus
authors.initials: C
authors.lastname: Lüers
authors.forename: Michael M
authors.initials: MM
authors.lastname: Kochen
authors.forename: Dirk
authors.initials: D
authors.lastname: Wetzel
authors.forename: Sibylle
authors.initials: S
authors.lastname: Kleta
authors.forename: Claudia
authors.initials: C
authors.lastname: Pouwels
authors.forename: Rolf
authors.initials: R
authors.lastname: Wachter
authors.forename: Christoph
authors.initials: C
authors.lastname: Herrmann-Lingen
authors.forename: Burkert
authors.initials: B
authors.lastname: Pieske
authors.forename: Lutz
authors.initials: L
authors.lastname: Binder
mesh_terms: D000368:Aged; D004452:Echocardiography; D005260:Female; D005858:Germany; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011320:Primary Health Care; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging
chemical_list: D020097:Natriuretic Peptide, Brain