title: Mode of hospital presentation in patients with non-ST-elevation myocardial infarction: implications for strategic management.
abstract: BACKGROUND
  Contemporary non-ST-elevation myocardial infarction-acute coronary syndrome guidelines emphasize early-risk stratification and optimizing therapy including an invasive strategy in high-risk patients. To assess the feasibility of initiating this strategy in the prehospital environment, we examined how such patients are transported to hospital, their risk profile, and the proportion potentially eligible for such a strategy.
  
  
  METHODS
  Consecutive patients with ST-segment elevation myocardial infarction admitted in Edmonton were studied between September and November 2008 and divided according to their mode of transport to hospital: emergency medical services (EMS) versus self-presenting. Baseline characteristics, GRACE Risk Score, blinded core laboratory electrocardiogram analysis, cardiac biomarkers, in-hospital procedures, and outcomes were analyzed.
  
  
  RESULTS
  Thirty-five percent (93/263) of patients presented via EMS and often to percutaneous coronary intervention hospitals, that is, 64.5% versus 44.1% (P = .0016). They were older (75 vs 62 years, P < .001), more often female (43% vs 28.1%, P < .001), diabetic (34.4% vs 22.9%, P = .045), and hypertensive (72.0% vs 57.1%, P = .017) and had higher GRACE Risk Scores (median 166 vs 130, P < .001). Electrocardiogram analysis revealed more baseline Q waves (38.8% vs 25.5%, P = .031) and ST depression ≥2 mm (P = .027) in EMS-transported patients. Fewer EMS patients underwent cardiac catheterization (60.2% vs 88.2%, P < .001), and a paradoxical relationship existed between catheterization rates and GRACE Risk Score in the total cohort (low-risk: 93.4% vs high-risk: 59.3%, P < .001). The composite of death/re-myocardial infarction/congestive heart failure/shock was greater in EMS patients (unadjusted odds ratio 3.96, 95% CI 1.80-8.69, P = .001); these differences were attenuated after GRACE Risk Score adjustment.
  
  
  CONCLUSIONS
  Regional strategies using risk-based triage, early medical therapy, and timely triage to percutaneous coronary intervention centers represents an unrealized opportunity to enhance ST-segment elevation myocardial infarction care.
authors: Division of Cardiology, Department of Medicine, University of Alberta, Alberta, Canada.
authors: Wayne
authors: W
authors: Tymchak
authors: Paul W
authors: PW
authors: Armstrong
authors: Cynthia M
authors: CM
authors: Westerhout
authors: Sunil
authors: S
authors: Sookram
authors: Neil
authors: N
authors: Brass
authors: Yuling
authors: Y
authors: Fu
authors: Robert C
authors: RC
authors: Welsh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization / Q000379:methods*; D004562:Electrocardiography; D004632:Emergency Medical Services / Q000592:standards*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D009204:Myocardial Revascularization / Q000379:methods*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013997:Time Factors