title: Association of left-heart dysfunction with severe exacerbation of chronic obstructive pulmonary disease: diagnostic performance of cardiac biomarkers.
abstract: BACKGROUND
  Cardiac biomarkers are used to distinguish acute dyspnea due to left-heart dysfunction from that of pulmonary origin. However, they have not been assessed in the specific setting of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), where they might be released without left-heart impairment.
  
  
  OBJECTIVE
  To assess the accuracy of troponin T and of amino-terminal pro-brain natriuretic peptide (NT-proBNP) in the diagnosis of AECOPD associated with left ventricular (LV) dysfunction.
  
  
  METHODS
  Both biomarkers were measured in 148 consecutive patients on intensive care unit admission for AECOPD. A panel of physicians adjudicated blindly the cause of AECOPD to be unlikely, possibly associated, or definitely associated with LV dysfunction.
  
  
  RESULTS
  The final diagnosis was AECOPD definitely associated with acute left-heart dysfunction in 31.1%, possibly associated with LV dysfunction in 13.5%, and probably not associated with LV dysfunction in 55.4%. Both NT-proBNP and troponin T levels were significantly different among the three groups. The area under the receiver operating characteristic curve was greater for NT-proBNP (0.95 vs. 0.67). A cutoff of 1,000 pg/ml was accurate to rule out left-heart involvement in AECOPD (sensitivity, 94%; negative predictive value, 94%; negative likelihood ratio, 0.08). A cutoff of 2,500 pg/ml had the best operating characteristics to rule in the diagnosis (positive likelihood ratio, 5.16). Left-heart involvement in AECOPD was the only variable independently associated with increased secretion of NT-proBNP (odds ratio, 74; 95% confidence interval, 15-375; p = 0.0001).
  
  
  CONCLUSIONS
  NT-proBNP and troponin T are useful in excluding AECOPD associated with left ventricular dysfunction. NT-proBNP was the more accurate of the two.
authors.affiliation: Intensive Care Unit, Department of Cardiology and Biochemistry Laboratory, Fattouma Bourguiba University Hospital, Monastir, Tunisia. f.abroug@rns.tn
authors.forename: Fekri
authors.initials: F
authors.lastname: Abroug
authors.forename: Lamia
authors.initials: L
authors.lastname: Ouanes-Besbes
authors.forename: Noureddine
authors.initials: N
authors.lastname: Nciri
authors.forename: Noura
authors.initials: N
authors.lastname: Sellami
authors.forename: Faouzi
authors.initials: F
authors.lastname: Addad
authors.forename: Khaldoun Ben
authors.initials: KB
authors.lastname: Hamda
authors.forename: Adel Ben
authors.initials: AB
authors.lastname: Amor
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Najjar
authors.forename: Jalel
authors.initials: J
authors.lastname: Knani
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood*; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications*; D012372:ROC Curve; D020107:Troponin T / Q000097:blood*; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000150:complications / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D011498:Protein Precursors; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain