title: Prognostic value of high-sensitivity troponin I versus troponin T in acute coronary syndromes.
abstract: BACKGROUND
  Despite superior diagnostic accuracy of high-sensitivity cardiac troponins, their prognostic value has not been validated against conventional cardiac troponins.
  
  
  OBJECTIVE
  To test the prognostic value of high-sensitivity cardiac troponin I (hs-cTnI), compared with conventional cardiac troponin T (cTnT) in the setting of non-ST elevation acute coronary syndromes.
  
  
  METHODS
  At hospital admission, a plasma sample was collected from 103 consecutive patients with unstable angina or non-ST elevation acute myocardial infarction. In this sample, troponin was measured both by hs-cTnI and cTnT methods. Their prognostic value was compared as to the occurrence of major cardiovascular events, defined as a combination of death, nonfatal acute myocardial infarction or refractory unstable angina during hospitalization.
  
  
  RESULTS
  During median hospitalization of 8 days (interquartile range = 5 - 11), the incidence of cardiovascular events was 10% (5 deaths, 3 non-fatal myocardial infarctions and 2 non-fatal refractory anginas). High-sensitivity troponin I significantly predicted cardiovascular events, with a C-statistics of 0.73 (95% CI = 0.59 - 0.87), similarly to cTnT (0.70; 95% CI = 0.55 - 0.84) - P = 0.75. The definition of positive cardiac marker that provided the best prognostic accuracy was hs-cTnI > 0.055 µg/L and cTnT > 0.010 µg/L, with equal sensitivity of 90% and specificity of 52% for both assays. Positive hs-cTnI was associated with 17% incidence of events, compared with 2% in patients with negative hs-cTnI (P = 0.02).
  
  
  CONCLUSIONS
  High-sensitivity troponin I predicts cardiovascular events similarly to conventional troponin T in the setting of non-ST-elevation ACS.
authors.affiliation: Faculdade de Medicina da Bahia, Salvador, BA, Brazil. lccorreia@cardiol.br
authors.forename: Luis C L
authors.initials: LC
authors.lastname: Correia
authors.forename: Fábio L
authors.initials: FL
authors.lastname: Sodré
authors.forename: José C C
authors.initials: JC
authors.lastname: Lima
authors.forename: Michael
authors.initials: M
authors.lastname: Sabino
authors.forename: Mariana
authors.initials: M
authors.lastname: Brito
authors.forename: Guilherme
authors.initials: G
authors.lastname: Garcia
authors.forename: Mayara
authors.initials: M
authors.lastname: Maraux
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Sousa
authors.forename: Márcia
authors.initials: M
authors.lastname: Noya-Rabelo
authors.forename: J Péricles
authors.initials: JP
authors.lastname: Esteves
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000401:mortality; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors; D019210:Troponin I / Q000097:blood*; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I; D020107:Troponin T