title: Nationwide improvement of door-to-balloon times in patients with acute ST-segment elevation myocardial infarction requiring primary percutaneous coronary intervention with out-of-hospital 12-lead ECG recording and transmission.
abstract: OBJECTIVE
  Reducing door-to-balloon times for acute ST-segment elevation myocardial infarction (STEMI) patients has been shown to improve long-term survival. We aim to reduce door-to-balloon time for STEMI patients requiring primary percutaneous coronary intervention by adoption of out-of-hospital 12-lead ECG transmission by Singapore's national ambulance service.
  
  
  METHODS
  This was a nationwide, before-after study of STEMI patients who presented to the emergency departments (ED) and required percutaneous coronary intervention. In the before phase, chest pain patients received 12-lead ECGs in the ED. In the after phase, 12-lead ECGs were performed by ambulance crews and transmitted from the field to the ED. Patients whose ECG showed greater than or equal to 2 mm ST-segment elevation in anterior or greater than or equal to 1 mm ST-segment elevation in inferior leads for 2 or more contiguous leads and symptom onset of less than 12 hours' duration were eligible for percutaneous coronary intervention activation before arrival.
  
  
  RESULTS
  ECGs (2,653) were transmitted by the ambulance service; 180 (7%) were suspected STEMI. One hundred twenty-seven patients from the before and 156 from the after phase met inclusion criteria for analysis. Median door-to-balloon time was 75 minutes in the before and 51 minutes in the after phase (median difference=23 minutes; 95% confidence interval 18 to 27 minutes). Median door-to-balloon times were significantly reduced regardless of presentation hours. Overall, there was significant reduction in door-to-activation, door-to-ECG, and door-to-cardiovascular laboratory times. No significant difference was found pertaining to adverse events.
  
  
  CONCLUSIONS
  This study describes a nationwide implementation of out-of-hospital ECG transmission resulting in reduced door-to-balloon times, regardless of presentation hours. Out-of-hospital ECG transmission should be adopted as best practice for management of chest pain.
authors.affiliation: Department of Emergency Medicine, Singapore General Hospital, Singapore. marcus.ong.e.h@sgh.com.sg
authors.forename: Marcus Eng Hock
authors.initials: ME
authors.lastname: Ong
authors.forename: Aaron Sung Lung
authors.initials: AS
authors.lastname: Wong
authors.forename: Chong Meng
authors.initials: CM
authors.lastname: Seet
authors.forename: Swee Guan
authors.initials: SG
authors.lastname: Teo
authors.forename: Beng Leong
authors.initials: BL
authors.lastname: Lim
authors.forename: Paul Jau Lueng
authors.initials: PJ
authors.lastname: Ong
authors.forename: Shieh Mei
authors.initials: SM
authors.lastname: Lai
authors.forename: Sea Hing
authors.initials: SH
authors.lastname: Ong
authors.forename: Francis Chun Yue
authors.initials: FC
authors.lastname: Lee
authors.forename: Kim Poh
authors.initials: KP
authors.lastname: Chan
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Anantharaman
authors.forename: Terrance Siang Jin
authors.initials: TS
authors.lastname: Chua
authors.forename: Pin Pin
authors.initials: PP
authors.lastname: Pek
authors.forename: Huihua
authors.initials: H
authors.lastname: Li
mesh_terms: D000552:Ambulances / Q000706:statistics & numerical data; D015906:Angioplasty, Balloon, Coronary / Q000592:standards / Q000706:statistics & numerical data*; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data; D004632:Emergency Medical Services / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D012846:Singapore; D013997:Time Factors; D016896:Treatment Outcome