title: Hospital process intervals, not EMS time intervals, are the most important predictors of rapid reperfusion in EMS Patients with ST-segment elevation myocardial infarction.
abstract: OBJECTIVE
  To assess the relationship of emergency medical services (EMS) intervals and internal hospital intervals to the rapid reperfusion of patients with ST-segment elevation myocardial infarction (STEMI).
  
  
  METHODS
  We performed a secondary analysis of a prospectively collected database of STEMI patients transported to a large academic community hospital between January 1, 2004, and December 31, 2009. EMS and hospital data intervals included EMS scene time, transport time, hospital arrival to myocardial infarction (MI) team activation (D2Page), page to catheterization laboratory arrival (P2Lab), and catheterization laboratory arrival to reperfusion (L2B). We used two outcomes: EMS scene arrival to reperfusion (S2B) ≤90 minutes and hospital arrival to reperfusion (D2B) ≤90 minutes. Means and proportions are reported. Pearson chi-square and multivariate regression were used for analysis.
  
  
  RESULTS
  During the study period, we included 313 EMS-transported STEMI patients with 298 (95.2%) MI team activations. Of these STEMI patients, 295 (94.2%) were taken to the cardiac catheterization laboratory and 244 (78.0%) underwent percutaneous coronary intervention (PCI). For the patients who underwent PCI, 127 (52.5%) had prehospital EMS activation, 202 (82.8%) had D2B ≤90 minutes, and 72 (39%) had S2B ≤90 minutes. In a multivariate analysis, hospital processes EMS activation (OR 7.1, 95% CI 2.7, 18.4], Page to Lab [6.7, 95% CI 2.3, 19.2] and Lab arrival to Reperfusion [18.5, 95% CI 6.1, 55.6]) were the most important predictors of Scene to Balloon ≤ 90 minutes. EMS scene and transport intervals also had a modest association with rapid reperfusion (OR 0.85, 95% CI 0.78, 0.93 and OR 0.89, 95% CI 0.83, 0.95, respectively). In a secondary analysis, Hospital processes (Door to Page [OR 44.8, 95% CI 8.6, 234.4], Page 2 Lab [OR 5.4, 95% CI 1.9, 15.3], and Lab arrival to Reperfusion [OR 14.6 95% CI 2.5, 84.3]), but not EMS scene and transport intervals were the most important predictors D2B ≤90 minutes.
  
  
  CONCLUSIONS
  In our study, hospital process intervals (EMS activation, door to page, page to laboratory, and laboratory to reperfusion) are key covariates of rapid reperfusion for EMS STEMI patients and should be used when assessing STEMI care.
authors: Department of Emergency Medicine William Beaumont Hospital, Royal Oak, Michigan 48703, USA.
authors: Carol Lynn
authors: CL
authors: Clark
authors: Aaron D
authors: AD
authors: Berman
authors: Ann
authors: A
authors: McHugh
authors: Edward Jedd
authors: EJ
authors: Roe
authors: Judith
authors: J
authors: Boura
authors: Robert A
authors: RA
authors: Swor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D016009:Chi-Square Distribution; D016001:Confidence Intervals; D017598:Efficiency, Organizational; D004632:Emergency Medical Services; D005260:Female; D006297:Health Services Accessibility; D006761:Hospitals; D006801:Humans; D007755:Laboratories, Hospital; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000295:instrumentation / Q000379:methods*; D016017:Odds Ratio; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome