title: Comparison of QTc and Troponin Levels in ST Elevation MIs Compared with Non-ST Elevation MIs.
abstract: ST elevation myocardial infarctions (STEMIs) and non-ST elevation myocardial infarctions (NSTEMIs) have differences that can be important to differentiate. Our primary hypothesis was that corrected QT (QTc) duration and troponin I levels were higher in STEMIs compared with NSTEMIs. The objective of our study was to compare STEMIs with NSTEMIs for QTc duration and troponin levels.
  
  
  
  This was a retrospective case-control study of all STEMIs and a random sample of NSTEMIs during a 1-year period. STEMIs were retrieved by searching our electrocardiogram database for all of the cardiology-diagnosed STEMIs. NSTEMIs were found by selecting a randomized sample of all of the patients with a final discharge diagnosis of NSTEMI. Records and electrocardiograms were reviewed for initial troponin I levels and QTc duration. Data extractors were educated formally and a 5% sample was reevaluated by the other extractor as a reliability measure. Data analysis included χ2tests and parametric or nonparametric analysis, where appropriate. A logistic regression model was created with variables selected a priori for predictors of STEMIs compared with NSTEMIs.
  
  
  
  A total of 92 STEMIs and 111 NSTEMIs were evaluated, and interrater reliability showed 90% agreement. Patients with NSTEMIs had significantly longer QTc. Troponin I did not differ on univariate analysis. In a logistic model, Hispanics were more likely than whites to have a STEMI (adjusted odds ratio [AOR] 2.2, 95% confidence interval [CI] 1.09-4.5). An increase in troponin I of 1 was associated with a 7% increase in the AOR of a STEMI (AOR 1.7, 95% CI 1.03-1.12) and an increase in QTc by 10 was associated with a 13% decrease in the AOR of a STEMI (AOR 0.87, 95% CI 0.78-0.93).
  
  
  
  Patients with NSTEMIs had longer QTc intervals and lower troponin I levels than those with STEMIs.
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Nathan
authors.initials: N
authors.lastname: Henrie
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Bryan
authors.initials: B
authors.lastname: Harvell
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Amy A
authors.initials: AA
authors.lastname: Ernst
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Weiss
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Scott
authors.initials: S
authors.lastname: Oglesbee
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Dusadee
authors.initials: D
authors.lastname: Sarangarm
authors.affiliation: From the Department of Emergency Medicine, University of New Mexico, Albuquerque.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Hernandez
mesh_terms: D006328:Cardiac Catheterization / Q000706:statistics & numerical data; D016022:Case-Control Studies; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000097:blood* / Q000453:epidemiology* / Q000628:therapy; D044469:Racial Groups; D012189:Retrospective Studies; D000072657:ST Elevation Myocardial Infarction / Q000097:blood* / Q000453:epidemiology / Q000628:therapy; D015607:Stents; D019210:Troponin I / Q000097:blood*
chemical_list: D019210:Troponin I