title: Pre-hospital triage for primary angioplasty: direct referral to the intervention center versus interhospital transport.
abstract: OBJECTIVE
  We sought to study the impact of direct referral to an intervention center after pre-hospital diagnosis of ST-segment elevation myocardial infarction (STEMI) on treatment intervals and outcome.
  
  
  BACKGROUND
  Primary angioplasty has become the preferred reperfusion strategy in STEMI. Ambulance diagnosis and direct referral to an intervention center is an attractive treatment option that has not been studied extensively.
  
  
  METHODS
  Consecutive pre-hospital patients with STEMI, who were referred to our intervention center for primary angioplasty between 2005 and 2007, were studied. After pre-hospital diagnosis, patients were either directly transported to our center or referred through a nonintervention center. The catheterization laboratory was activated before transport to the intervention center.
  
  
  RESULTS
  Of the 581 patients referred, 454 (78%) came with direct transport and 127 (22%) through a nonintervention center. Direct transport was associated with a higher proportion of patients treated within the 90-min time window of the STEMI guidelines: 82% versus 23% (p < 0.01). Patients directly transported had a significantly shorter median symptom-to-balloon time of 149 min (Interquartile range: 118 to 197 min) versus 219 min (interquartile range: 178 to 315 min), p < 0.01, a higher post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 rate (92% vs. 84%; p = 0.03), and a lower 1-year mortality rate (7% vs. 13%; p = 0.03). Direct transport to the intervention center was independently associated with the symptom-to-balloon time, which in turn was an independent predictor of post-procedural TIMI flow grade 3, a strong prognosticator of outcome.
  
  
  CONCLUSIONS
  After ambulance-based diagnosis of STEMI, direct transport to an intervention center with pre-hospital notification of the catheterization laboratory more than triples the proportion of patients treated within the time window of the guidelines. Time to balloon was an independent predictor of post-procedural TIMI flow grade 3, which underscores the need to reduce treatment delays.
authors.affiliation: Department of Cardiology, Heart Lung Center, Radboud University Medical Center, Nijmegen, the Netherlands. h.dieker@cardio.umcn.nl
authors.forename: Hendrik-Jan
authors.initials: HJ
authors.lastname: Dieker
authors.forename: Stephan S B
authors.initials: SS
authors.lastname: Liem
authors.forename: Hamza
authors.initials: H
authors.lastname: El Aidi
authors.forename: Pierre
authors.initials: P
authors.lastname: van Grunsven
authors.forename: Wim R M
authors.initials: WR
authors.lastname: Aengevaeren
authors.forename: Marc A
authors.initials: MA
authors.lastname: Brouwer
authors.forename: Freek W A
authors.initials: FW
authors.lastname: Verheugt
mesh_terms: D000368:Aged; D000552:Ambulances; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D004632:Emergency Medical Services; D005260:Female; D019983:Guideline Adherence; D006297:Health Services Accessibility; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D009426:Netherlands; D010348:Patient Care Team; D010360:Patient Transfer; D017410:Practice Guidelines as Topic; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012017:Referral and Consultation; D012111:Residence Characteristics; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014218:Triage