title: [Usefulness of the N-terminal fraction of brain natriuretic peptide for deciding when to refer patients with sleep apnea-hypopnea syndrome to the cardiologist].
abstract: OBJECTIVE
  When sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.
  
  
  METHODS
  NT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.
  
  
  RESULTS
  Data for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular end-diastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.
  
  
  CONCLUSIONS
  NT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.
authors.affiliation: Servicio de Neumología, Hospital Universitario Dr. Peset, Valencia, España. fernandez_est@gva.es
authors.forename: Estrella
authors.initials: E
authors.lastname: Fernández Fabrellas
authors.forename: Luis
authors.initials: L
authors.lastname: Almenar Bonet
authors.forename: Silvia
authors.initials: S
authors.lastname: Ponce Pérez
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Moro López
authors.forename: Rafael
authors.initials: R
authors.lastname: Blanquer Olivas
authors.forename: Antonio
authors.initials: A
authors.lastname: Salvador Sanz
mesh_terms: D002309:Cardiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012017:Referral and Consultation; D012891:Sleep Apnea Syndromes / Q000097:blood* / Q000628:therapy*
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain