title: Impact of reperfusion strategy on aborted myocardial infarction: insights from a large Canadian ST-Elevation Myocardial Infarction Clinical Registry.
abstract: BACKGROUND
  Reperfusion in ST-elevation myocardial infarction (STEMI) improves survival. Moreover, early reperfusion can abort the infarct and avoid significant myocardial necrosis. Yet, limited real world data exist and comparison between reperfusion strategies has not been established.
  
  
  METHODS
  Using a comprehensive Canadian registry of consecutive STEMI patients, we prospectively collected serial electrocardiograms (ECGs) and clinical data from August 2006 to March 2011. Aborted myocardial infarction (AbMI) was defined as a maximal creatine kinase ≤ 2 times the upper limit of normal with evolutionary ECG changes of STEMI. ECG confounders and subjects with incomplete data were excluded.
  
  
  RESULTS
  Of the 2235 STEMI patients reperfused within 12 hours, 16.0% were considered to have an AbMI. Numerically, higher rates of AbMI with fibrinolysis vs primary percutaneous coronary intervention were reported (17.0% vs 14.7%; P = 0.15) with a temporal pattern seen up to 4 hours from symptom onset in favour of fibrinolysis (P trend < 0.001). Most notably, the highest frequency of AbMI was observed within the first hour with fibrinolysis (31.1%). Improved in-hospital outcomes (death/shock/congestive heart failure) were seen with AbMI (5.6% vs 13.6%; P < 0.001; adjusted odds ratio, 0.22; 95% confidence interval, 0.08-0.57).
  
  
  CONCLUSIONS
  In a large contemporary Canadian STEMI registry, AbMI appears to be common and associated with improved clinical outcome. Early reperfusion seems to enhance AbMI particularly when fibrinolysis is administered within 1 hour of symptom onset.
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Bainey
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Craig
authors.initials: C
authors.lastname: Ferguson
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Quazi I
authors.initials: QI
authors.lastname: Ibrahim
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Ben
authors.initials: B
authors.lastname: Tyrrell
authors.affiliation: Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada. Electronic address: rwelsh@cha.ab.ca.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Welsh
mesh_terms: D000368:Aged; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D011446:Prospective Studies; D015912:Thrombolytic Therapy / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents