title: The importance of troponin I in the diagnosis of myocardial infarction in the postoperative of coronary artery bypass graft surgery.
abstract: OBJECTIVE
  The aim of this study is to establish a cut-off value for troponin I by correlating it to occurrence of postoperative myocardial infarction.
  
  
  METHODS
  180 consecutive patients with coronary disease referred for surgery were included. The mean age of the patients were 60.6 (+/-9.3) years, with 119 (66.1%) males and 61 (33.9%) females. The patients were divided into two groups: group without myocardial infarction (A)--170 patients--and with myocardial infarction (B)--10 patients.The troponin I was collected from each patient at the beginning of anesthesia and on the second postoperative day by correlating it to presence or not of postoperative myocardial infarction. StatsDirect 1.6.0 for Windows was used for statistical analysis.
  
  
  RESULTS
  Preoperative troponin I was 1.0 (+/-6) ng/ml as mean. Univariate logistic regression showed correlation of troponin I of the second postoperative day with myocardial infarction (P=0.0005). ROC curve was used to define the cutoff value, and 6.1 ng/ml (sensitivity=90.0%, specificity=82.1%, OR=49.8 with CI=95% 6.1- 410.4, P<0.0001) were found.
  
  
  CONCLUSIONS
  The chance of a patient with postoperative myocardial infarction to present troponin I equal to or higher than 6.1 ng/ml is 49.8-fold higher than the chance of a patient without infarction to present troponin I higher than this value.
authors.affiliation: São José do Rio Preto Medical School, São José do Rio Preto. m_aurelio@sbccv.org.br
authors.forename: Marcos Aurélio Barboza de
authors.initials: MA
authors.lastname: Oliveira
authors.forename: Paulo Henrique Husseni
authors.initials: PH
authors.lastname: Botelho
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Brandi
authors.forename: Carlos Alberto dos
authors.initials: CA
authors.lastname: Santos
authors.forename: Marcelo José Ferreira
authors.initials: MJ
authors.lastname: Soares
authors.forename: Marcos
authors.initials: M
authors.lastname: Zaiantchick
authors.forename: Maurício de Nassau
authors.initials: MN
authors.lastname: Machado
authors.forename: Moacir Fernandes de
authors.initials: MF
authors.lastname: Godoy
authors.forename: Domingo Marcolino
authors.initials: DM
authors.lastname: Braile
mesh_terms: D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis*; D012016:Reference Values; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I