title: Causes of delay and associated mortality in patients transferred with ST-segment-elevation myocardial infarction.
abstract: BACKGROUND
  Regional ST-segment-elevation myocardial infarction systems are being developed to improve timely access to primary percutaneous coronary intervention (PCI). System delays may diminish the mortality benefit achieved with primary PCI in ST-segment-elevation myocardial infarction patients, but the specific reasons for and clinical impact of delays in patients transferred for PCI are unknown.
  
  
  RESULTS
  This was a prospective, observational study of 2034 patients transferred for primary PCI at a single center as part of a regional ST-segment-elevation myocardial infarction system from March 2003 to December 2009. Despite long-distance transfers, 30.4% of patients (n=613) were treated in ≤ 90 minutes and 65.7% (n=1324) were treated in ≤ 120 minutes. Delays occurred most frequently at the referral hospital (64.0%, n=1298), followed by the PCI center (15.7%, n=317) and transport (12.6%, n=255). For the referral hospital, the most common reasons for delay were awaiting transport (26.4%, n=535) and emergency department delays (14.3%, n=289). Diagnostic dilemmas (median, 95.5 minutes; 25th and 75th percentiles, 72-127 minutes) and nondiagnostic initial ECGs (81 minutes; 64-110.5 minutes) led to delays of the greatest magnitude. Delays caused by cardiac arrest and/or cardiogenic shock had the highest in-hospital mortality (30.6%), in contrast with nondiagnostic initial ECGs, which, despite long treatment delays, did not affect mortality (0%). Significant variation in both the magnitude and clinical impact of delays also occurred during the transport and PCI center segments.
  
  
  CONCLUSIONS
  Treatment delays occur even in efficient systems for ST-segment-elevation myocardial infarction care. The clinical impact of specific delays in interhospital transfer for PCI varies according to the cause of the delay.
authors.affiliation: Minneapolis Heart Institute Foundation, 920 E 28th St, Ste 100, Minneapolis, MN 55407, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Miedema
authors.forename: Marc C
authors.initials: MC
authors.lastname: Newell
authors.forename: Sue
authors.initials: S
authors.lastname: Duval
authors.forename: Ross F
authors.initials: RF
authors.lastname: Garberich
authors.forename: Chauncy B
authors.initials: CB
authors.lastname: Handran
authors.forename: David M
authors.initials: DM
authors.lastname: Larson
authors.forename: Steven
authors.initials: S
authors.lastname: Mulder
authors.forename: Yale L
authors.initials: YL
authors.lastname: Wang
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Lips
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Henry
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003695:Delivery of Health Care; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D010360:Patient Transfer; D011446:Prospective Studies; D012017:Referral and Consultation; D013997:Time Factors