title: Impact of time of presentation on the care and outcomes of acute myocardial infarction.
abstract: BACKGROUND
  Prior studies have demonstrated an inconsistent association between patients' arrival time for acute myocardial infarction (AMI) and their subsequent medical care and outcomes.
  
  
  RESULTS
  Using a contemporary national clinical registry, we examined differences in medical care and in-hospital mortality among AMI patients admitted during regular hours (weekdays 7 am to 7 pm) versus off-hours (weekends, holidays, and 7 pm to 7 am weeknights). The study cohort included 62,814 AMI patients from the Get With the Guidelines-Coronary Artery Disease database admitted to 379 hospitals throughout the United States from July 2000 through September 2005. Overall, 33 982 (54.1%) patients arrived during off-hours. Compared with those arriving during regular hours, eligible off-hour patients were slightly less likely to receive primary percutaneous coronary intervention (adjusted odds ratio [OR], 0.93; 95% confidence interval [CI], 0.89 to 0.98), had longer door-to-balloon times (median, 110 versus 85 minutes; P<0.0001), and were less likely to achieve door-to-balloon < or = 90 minutes (adjusted OR, 0.34; 95% CI, 0.29 to 0.39). Arrival during off-hours was associated with slightly lower overall revascularization rates (adjusted OR, 0.94; 95% CI, 0.90 to 0.97). No measurable differences, however, were found in in-hospital mortality between regular hours and off-hours in the overall AMI, ST-elevated MI, and non-ST-elevated MI cohorts (adjusted OR, 0.99; 95% CI, 0.93 to 1.06; adjusted OR, 1.05; 95% CI, 0.94 to 1.18; and adjusted OR, 0.97; 95% CI, 0.90 to 1.04, respectively). Similar observations were made across most age and sex subgroups and with an alternative definition for arrival time (weekends/holidays versus weekdays).
  
  
  CONCLUSIONS
  Despite slightly fewer primary percutaneous coronary interventions and overall revascularizations and significantly longer door-to-balloon times, patients presenting with AMI during off-hours had in-hospital mortality similar to those presenting during regular hours.
authors.affiliation: Division of Cardiology, Massachusetts General Hospital, 55 Fruit St, GRB 800 Boston, MA 02114. jneid.hani@mgh.harvard.edu.
authors.forename: Hani
authors.initials: H
authors.lastname: Jneid
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Cannon
authors.forename: Igor F
authors.initials: IF
authors.lastname: Palacios
authors.forename: Teoman
authors.initials: T
authors.lastname: Kilic
authors.forename: George V
authors.initials: GV
authors.lastname: Moukarbel
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Maree
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: LaBresh
authors.forename: Li
authors.initials: L
authors.lastname: Liang
authors.forename: L Kristin
authors.initials: LK
authors.lastname: Newby
authors.forename: Gerald
authors.initials: G
authors.lastname: Fletcher
authors.forename: Laura
authors.initials: L
authors.lastname: Wexler
authors.forename: Eric
authors.initials: E
authors.lastname: Peterson
mesh_terms: D039602:After-Hours Care / Q000592:standards*; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy*; D009204:Myocardial Revascularization / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians'; D044469:Racial Groups; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome