title: Impact of ECG findings and process-of-care characteristics on the likelihood of not receiving reperfusion therapy in patients with ST-elevation myocardial infarction: results of a field evaluation.
abstract: BACKGROUND
  Many patients with ST-elevation myocardial infarction (STEMI) do not receive reperfusion therapy and are known to have poorer outcomes. We aimed to perform the first population-level, integrated analysis of clinical, ECG and hospital characteristics associated with non-receipt of reperfusion therapy in patients with STEMI.
  
  
  RESULTS
  This systematic evaluation of STEMI care in 82 hospitals in Quebec included all patients with a discharge diagnosis of myocardial infarction, presenting with characteristic symptoms and an ECG showing STEMI as attested by at least one of two study cardiologists or left bundle branch block (LBBB). Excluding LBBB, an ECG was considered a definite STEMI diagnosis if both cardiologists scored 'certain STEMI' and ambiguous if one scored 'uncertain' or 'not STEMI'. Centers were classified according to accessibility to primary percutaneous coronary intervention (PPCI): 1) on-site PPCI; 2) routine transfer for PPCI; 3) varying mix of PPCI transfer and on-site fibrinolysis; and 4) routine on-site fibrinolysis. Of 3730 STEMI/LBBB patients, 812 (21.8%) did not receive reperfusion therapy. In multivariate analysis, likelihood of no reperfusion therapy was a function of PPCI accessibility (odds ratio [OR] for fibrinolysis versus PPCI centers = 3.1; 95% CI: 2.2-4.4), presence of LBBB (OR = 24.1; 95% CI: 17.8-32.9) and an ECG ambiguous for STEMI (OR = 4.1; 95% CI: 3.3-5.1). When the ECG was ambiguous, likelihood of no reperfusion therapy was highest in hospitals most distant from PPCI centers.
  
  
  CONCLUSIONS
  ECG diagnostic ambiguity, LBBB and PPCI accessibility are important predictors of not receiving reperfusion therapy, suggesting opportunities for improving outcomes.
authors.affiliation: Institut national d'excellence en santé et en services sociaux (INESSS), Montréal, Québec, Canada.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Brown
authors.affiliation: Institut national d'excellence en santé et en services sociaux (INESSS), Montréal, Québec, Canada.
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Lambert
authors.affiliation: McGill University Health Center, Montréal, Québec, Canada.
authors.forename: James M
authors.initials: JM
authors.lastname: Brophy
authors.affiliation: St. Paul's Hospital, Vancouver, British Columbia, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Nasmith
authors.affiliation: Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Rinfret
authors.affiliation: Sir Mortimer B. Davis Jewish General Hospital, Montréal, Québec, Canada; Corporation d'Urgences-santé, Montréal, Québec, Canada.
authors.forename: Eli
authors.initials: E
authors.lastname: Segal
authors.affiliation: Centre hospitalier régional de Lanaudière, Joliette, Québec, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Kouz
authors.affiliation: Corporation d'Urgences-santé, Montréal, Québec, Canada; Services préhospitaliers d'urgence en Montérégie, Longueuil, Québec, Canada; Département de médecine préhospitalière, Hôpital Sacré-Cœur de Montréal, Montréal, Québec, Canada.
authors.forename: Dave
authors.initials: D
authors.lastname: Ross
authors.affiliation: Université de Sherbrooke, Sherbrooke, Québec, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Harvey
authors.affiliation: Centre hospitalier affilié universitaire Hôtel-Dieu de Lévis, Lévis, Québec, Canada.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Maire
authors.affiliation: Institut national d'excellence en santé et en services sociaux (INESSS), Montréal, Québec, Canada.
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Boothroyd
authors.affiliation: Institut national d'excellence en santé et en services sociaux (INESSS), Montréal, Québec, Canada; Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Bogaty
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000601:surgery*; D015425:Myocardial Reperfusion; D012189:Retrospective Studies