title: Symptom-to-door time in ST segment elevation myocardial infarction: overemphasized or overlooked? Results from the AMI-McGill study.
abstract: BACKGROUND
  Ischemic time is a major determinant of infarct size in ST segment elevation myocardial infarction (STEMI). Emphasis is placed on reducing the door-to-reperfusion therapy time component, whereas the symptom-to-door time is often overlooked.
  
  
  OBJECTIVE
  To correlate the symptom-to-door time with left ventricular ejection fraction (LVEF) in patients with STEMI.
  
  
  METHODS
  Acute Myocardial Infarction (AMI)-McGill was a cohort study of consecutive patients with STEMI who presented to three adult university hospitals. Multivariate linear regression was performed to correlate the symptom-to-door time with postinfarction LVEF adjusted for reperfusion method, prior myocardial infarction and components of the Thrombolysis In Myocardial Infarction (TIMI) risk score.
  
  
  RESULTS
  There were 188 patients, with a mean age of 66 years. On arrival to hospital, 23% of patients were in Killip class II to IV and 87% received reperfusion therapy (20% fibrinolytic therapy and 67% primary percutaneous coronary intervention). The median symptom-to-door time was 120 min (first quartile: 60 min, third quartile: 290 min) and the median door-to-reperfusion therapy time was 93 min (first quartile: 54 min, third quartile: 155 min). Three variables were independently correlated with LVEF in the study's regression model: symptom-to-door time (beta: -0.66, 95% CI -1.18 to -0.14; P=0.01), Killip class II to IV on arrival (beta: -6.43, 95% CI -11.87 to -0.99; P=0.02) and anterior territory of the infarction (beta: -5.86, 95% CI -10.55 to -1.18; P=0.02).
  
  
  CONCLUSIONS
  Symptom-to-door time was negatively correlated with postinfarction LVEF in patients with STEMI. Strategies to shorten this delay, such as educating high-risk patients about the symptoms of AMI, should be considered.
authors.affiliation: Sir Mortimer B Davis Jewish General Hospital, Montreal, Quebec.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Afilalo
authors.forename: Nicolo
authors.initials: N
authors.lastname: Piazza
authors.forename: Sonia
authors.initials: S
authors.lastname: Tremblay
authors.forename: Nathalie
authors.initials: N
authors.lastname: Soucy
authors.forename: Thao
authors.initials: T
authors.lastname: Huynh
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods; D013318:Stroke Volume; D015912:Thrombolytic Therapy; D013997:Time Factors; D016896:Treatment Outcome