title: Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain.
abstract: BACKGROUND
  Although chest pain is widely considered a key symptom in the diagnosis of myocardial infarction (MI), not all patients with MI present with chest pain. The extent to which this phenomenon occurs is largely unknown.
  
  
  OBJECTIVE
  To determine the frequency with which patients with MI present without chest pain and to examine their subsequent management and outcome.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  A total of 434,877 patients with confirmed MI enrolled June 1994 to March 1998 in the National Registry of Myocardial Infarction 2, which includes 1674 hospitals in the United States.
  
  
  METHODS
  Prevalence of presentation without chest pain; clinical characteristics, treatment, and mortality among MI patients without chest pain vs those with chest pain.
  
  
  RESULTS
  Of all patients diagnosed as having MI, 142,445 (33%) did not have chest pain on presentation to the hospital. This group of MI patients was, on average, 7 years older than those with chest pain (74.2 vs 66.9 years), with a higher proportion of women (49.0% vs 38.0%) and patients with diabetes mellitus (32.6% vs 25. 4%) or prior heart failure (26.4% vs 12.3%). Also, MI patients without chest pain had a longer delay before hospital presentation (mean, 7.9 vs 5.3 hours), were less likely to be diagnosed as having confirmed MI at the time of admission (22.2% vs 50.3%), and were less likely to receive thrombolysis or primary angioplasty (25.3% vs 74.0%), aspirin (60.4% vs 84.5%), beta-blockers (28.0% vs 48.0%), or heparin (53.4% vs 83.2%). Myocardial infarction patients without chest pain had a 23.3% in-hospital mortality rate compared with 9.3% among patients with chest pain (adjusted odds ratio for mortality, 2. 21 [95% confidence interval, 2.17-2.26]).
  
  
  CONCLUSIONS
  Our results suggest that patients without chest pain on presentation represent a large segment of the MI population and are at increased risk for delays in seeking medical attention, less aggressive treatments, and in-hospital mortality. JAMA. 2000;283:3223-3229
authors.affiliation: University of Alabama, 363 BDB, 1808 Seventh Ave S, Birmingham, AL 35294, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Canto
authors.forename: M G
authors.initials: MG
authors.lastname: Shlipak
authors.forename: W J
authors.initials: WJ
authors.lastname: Rogers
authors.forename: J A
authors.initials: JA
authors.lastname: Malmgren
authors.forename: P D
authors.initials: PD
authors.lastname: Frederick
authors.forename: C T
authors.initials: CT
authors.lastname: Lambrew
authors.forename: J P
authors.initials: JP
authors.lastname: Ornato
authors.forename: H V
authors.initials: HV
authors.lastname: Barron
authors.forename: C I
authors.initials: CI
authors.lastname: Kiefe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002637:Chest Pain; D004632:Emergency Medical Services; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D015995:Prevalence; D011446:Prospective Studies