title: Troponin must be measured before and after PCI to diagnose procedure-related myocardial injury.
abstract: OBJECTIVE
  To evaluate troponin I >99th percentile of normal as a criterion for myocardial injury after percutaneous coronary intervention (PCI).
  
  
  METHODS
  Troponin I and creatine kinase monobasic (CK-MB) were measured in 327 patients before and after percutaneous transluminal coronary angioplasty (PTCA) with stent implantation.
  
  
  RESULTS
  Troponin I was elevated before PCI in 100 of a total of 222 patients with acute coronary syndrome (ACS). In 91 of these 100 patients, troponin I was elevated also after PCI but actual increases in troponin I concentrations from before to after PCI were found in only 32 patients. The increase of troponin I correlated with post-procedural CK-MB whereas post-procedural troponin I levels did not correlate. In the 122 patients with ACS but normal/normalized troponin I before PCI and in 105 patients with stable coronary artery disease post-procedural troponin I appeared to be a reliable indicator of myocardial infarction (MI), however more sensitive than CK-MB.
  
  
  CONCLUSIONS
  Troponin I after PCI is sensitive to pre-procedural concentrations. To avoid false positive MI diagnoses we thus suggest that troponin I should be measured before as well as after the procedures and only actual increases should be regarded as indicating procedure-related MI.
authors.affiliation: Department of Cardiology, University Hospital, S-205 02 Malmö, Sweden. CG@Gustavsson.se
authors.forename: Carl Gunnar
authors.initials: CG
authors.lastname: Gustavsson
authors.forename: Ole
authors.initials: O
authors.lastname: Hansen
authors.forename: Bo
authors.initials: B
authors.lastname: Frennby
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000379:methods*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000097:blood / Q000628:therapy*; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000628:therapy*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I; D003402:Creatine Kinase