title: Earlier reperfusion in patients with ST-elevation myocardial infarction by use of helicopter.
abstract: BACKGROUND
  In patients with ST-elevation myocardial infarction (STEMI) reperfusion therapy should be initiated as soon as possible. This study evaluated whether use of a helicopter for transportation of patients is associated with earlier initiation of reperfusion therapy.
  
  
  METHODS
  A prospective study was conducted, including patients with STEMI and symptom duration less than 12 hours, who had primary percutaneous coronary intervention (PPCI) performed at Aarhus University Hospital in Skejby. Patients with a health care system delay (time from emergency call to first coronary intervention) of more than 360 minutes were excluded. The study period ran from 1.1.2011 until 31.12.2011. A Western Denmark Helicopter Emergency Medical Service (HEMS) project was initiated 1.6.2011 for transportation of patients with time-critical illnesses, including STEMI.
  
  
  RESULTS
  The study population comprised 398 patients, of whom 376 were transported by ambulance Emergency Medical Service (EMS) and 22 by HEMS. Field-triage directly to the PCI-center was used in 338 of patients. The median system delay was 94 minutes among those field-triaged, and 168 minutes among those initially admitted to a local hospital. Patients transported by EMS and field-triaged were stratified into four groups according to transport distance from the scene of event to the PCI-center: ≤25 km., 26-50 km., 51-75 km. and > 75 km. For these groups, the median system delay was 78, 89, 99, and 141 minutes. Among patients transported by HEMS and field-triaged the estimated median transport distance by ground transportation was 115 km, and the observed system delay was 107 minutes. Based on second order polynomial regression, it was estimated that patients with a transport distance of >60 km to the PCI-center may benefit from helicopter transportation, and that transportation by helicopter is associated with a system delay of less than 120 minutes even at a transport distance up to 150 km.
  
  
  CONCLUSIONS
  The present study indicates that use of a helicopter should be considered for field-triage of patients with STEMI to the PCI-center in case of long transportation. Such a strategy may ensure that patients living up to 150 km. from the PCI-center can be treated within 120 minutes of emergency call.
authors.affiliation: Helicopter Emergency Medical Service, Central Denmark Region, Aarhus, Denmark. Lars.Knudsen@dadlnet.dk
authors.forename: Lars
authors.initials: L
authors.lastname: Knudsen
authors.forename: Carsten
authors.initials: C
authors.lastname: Stengaard
authors.forename: Troels Martin
authors.initials: TM
authors.lastname: Hansen
authors.forename: Jens Flensted
authors.initials: JF
authors.lastname: Lassen
authors.forename: Christian Juhl
authors.initials: CJ
authors.lastname: Terkelsen
mesh_terms: D017732:Air Ambulances / Q000458:organization & administration; D015906:Angioplasty, Balloon, Coronary; D003718:Denmark; D006801:Humans; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion; D011446:Prospective Studies; D013997:Time Factors; D061665:Time-to-Treatment; D014218:Triage