title: Rapid point-of-care NT-proBNP optimal cut-off point for heart failure diagnosis in primary care.
abstract: OBJECTIVE
  Measurement of natriuretic peptides may be recommended prior to echocardiography in patients with suspected heart failure. Cut-off point for heart failure diagnosis in primary care is not well established. We aimed to assess the optimal diagnostic cut-off value of N-terminal pro-B-type natriuretic peptide on a community population attended in primary care.
  
  
  METHODS
  Prospective diagnostic accuracy study of a rapid point-of-care N-terminal pro-B-type natriuretic peptide test in a primary healthcare centre. Consecutive patients referred by their general practitioners to echocardiography due to suspected heart failure were included. Clinical history and physical examination based on Framingham criteria, electrocardiogram, chest X-ray, N-terminal pro-B-type natriuretic peptide measurement and echocardiogram were performed. Heart failure diagnosis was made by a cardiologist blinded to N-terminal pro-B-type natriuretic peptide value, using the European Society of Cardiology diagnosis criteria (clinical and echocardiographic data).
  
  
  RESULTS
  Of 220 patients evaluated (65.5% women; median 74 years [interquartile range 67-81]). Heart failure diagnosis was confirmed in 52 patients (23.6%), 16 (30.8%) with left ventricular ejection fraction <50% (39.6 [5.1]%). Median values of N-terminal pro-B-type natriuretic peptide were 715 pg/mL [interquartile range 510.5-1575] and 77.5 pg/mL [interquartile range 58-179.75] for patients with and without heart failure respectively. The best cut-off point was 280 pg/mL, with a receiver operating characteristic curve of 0.94 (95% confidence interval, 0.91-0.97). Six patients with heart failure diagnosis (11.5%) had N-terminal pro-B-type natriuretic peptide values <400 pg/mL. Measurement of natriuretic peptides would avoid 67% of requested echocardiograms.
  
  
  CONCLUSIONS
  In a community population attended in primary care, the best cut-off point of N-terminal pro-B-type natriuretic peptide to rule out heart failure was 280 pg/mL. N-terminal pro-B-type natriuretic peptide measurement improve work-out diagnoses and could be cost-effectiveness.
authors.affiliation: Equip d'Atenció Primària, Sant Martí de Provençals, Institut Català de la Salut, Barcelona, Spain. verdujm@gmail.com
authors.forename: José M
authors.initials: JM
authors.lastname: Verdú
authors.forename: Josep
authors.initials: J
authors.lastname: Comín-Colet
authors.forename: Mar
authors.initials: M
authors.lastname: Domingo
authors.forename: Josep
authors.initials: J
authors.lastname: Lupón
authors.forename: Miguel
authors.initials: M
authors.lastname: Gómez
authors.forename: Luis
authors.initials: L
authors.lastname: Molina
authors.forename: Jose M
authors.initials: JM
authors.lastname: Casacuberta
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Muñoz
authors.forename: Amparo
authors.initials: A
authors.lastname: Mena
authors.forename: Jordi
authors.initials: J
authors.lastname: Bruguera-Cortada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015897:Comorbidity; D016001:Confidence Intervals; D003362:Cost-Benefit Analysis; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D019095:Point-of-Care Systems / Q000191:economics; D011237:Predictive Value of Tests; D011320:Primary Health Care; D012372:ROC Curve; D018754:Ventricular Dysfunction / Q000175:diagnosis
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain