title: Exhaled acetone as a new biomaker of heart failure severity.
abstract: BACKGROUND
  Heart failure (HF) is associated with poor prognosis, and the identification of biomarkers of its severity could help in its treatment. In a pilot study, we observed high levels of acetone in the exhaled breath of patients with HF. The present study was designed to evaluate exhaled acetone as a biomarker of HF diagnosis and HF severity.
  
  
  METHODS
  Of 235 patients with systolic dysfunction evaluated between May 2009 and September 2010, 89 patients (HF group) fulfilled inclusion criteria and were compared with sex- and age-matched healthy subjects (control group, n = 20). Patients with HF were grouped according to clinical stability (acute decompensated HF [ADHF], n = 59; chronic HF, n = 30) and submitted to exhaled breath collection. Identification of chemical species was done by gas chromatography-mass spectrometry and quantification by spectrophotometry. Patients with diabetes were excluded.
  
  
  RESULTS
  The concentration of exhaled breath acetone (EBA) was higher in the HF group (median, 3.7 μg/L; interquartile range [IQR], 1.69-10.45 μg/L) than in the control group (median, 0.39 μg/L; IQR, 0.30-0.79 μg/L; P < .001) and higher in the ADHF group (median, 7.8 μg/L; IQR, 3.6-15.2 μg/L) than in the chronic HF group (median, 1.22 μg/L; IQR, 0.68-2.19 μg/L; P < .001). The accuracy and sensitivity of this method in the diagnosis of HF and ADHF were about 85%, a value similar to that obtained with B-type natriuretic peptide (BNP). EBA levels differed significantly as a function of severity of HF (New York Heart Association classification, P < .001). There was a positive correlation between EBA and BNP (r = 0.772, P < .001).
  
  
  CONCLUSIONS
  EBA not only is a promising noninvasive diagnostic method of HF with an accuracy equivalent to BNP but also a new biomarker of HF severity.
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. Electronic address: fgmarcondes@yahoo.com.br.
authors.forename: Fabiana G
authors.initials: FG
authors.lastname: Marcondes-Braga
authors.affiliation: Chemistry Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: Ivano G R
authors.initials: IGR
authors.lastname: Gutz
authors.affiliation: Chemistry Institute, University of São Paulo, São Paulo, Brazil.
authors.forename: Guilherme L
authors.initials: GL
authors.lastname: Batista
authors.affiliation: Laboratory of Experimental Air Pollution, Department of Pathology, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Paulo H N
authors.initials: PHN
authors.lastname: Saldiva
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Ayub-Ferreira
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Victor S
authors.initials: VS
authors.lastname: Issa
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Sandrigo
authors.initials: S
authors.lastname: Mangini
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Edimar A
authors.initials: EA
authors.lastname: Bocchi
authors.affiliation: Laboratory of Heart Failure, Heart Institute (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Bacal
mesh_terms: D000096:Acetone / Q000378:metabolism*; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D016022:Case-Control Studies; D045853:Exhalation / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D000096:Acetone