title: [Reduction of myocardial infarction mortality in Chilean hospitals].
abstract: BACKGROUND
  The characteristics of patients with acute myocardial infarction (MI) admitted to 37 Chilean hospitals (GEMI Registry Group), have been analyzed in the period 1993-1995 and 1997-1998.
  
  
  OBJECTIVE
  To report the changes in hospital mortality between these 2 periods, with a particular emphasis on the impact of treatment.
  
  
  METHODS
  Between 1993-1995 we collected information from 2,957 patients and between 1997-1998 we registered 1,981 patients with MI. Analysis of the changes in mortality between periods was adjusted by demographic variables, coronary risk factors, MI location, Killip class on admission and the different therapeutic strategies utilized. The effects of different treatments on hospital mortality were adjusted by the previously determined mortality risk variables.
  
  
  RESULTS
  Hospital mortality decreased from 13.3% to 10.8% between both periods (Odds Ratio (OR) 0.78, confidence intervals (95%) (CI) 0.65-0.93). A significant reduction in mortality was observed among patients below 60 years of age, in men, in diabetics and in subjects with an infarction classified as Killip class over II. The use of beta blockers (OR 0.65, CI 0.42-0.99) and intravenous nitrates (OR 0.78, CI 0.61-0.99) and the lower use of calcium channel blockers (OR 0.72, CI 0.60-0.87) were significantly associated with a lower mortality. The administration of angiotensin converting enzyme inhibitors was associated with a 29.3% mortality reduction (OR 0.69, CI 0.47-1.02).
  
  
  CONCLUSIONS
  There has been a significant reduction in the mortality rate for MI in Chilean hospitals during the 2 registry periods analyzed, which was significant among some high risk patients and was related to treatment changes, according to evidence based guidelines.
authors.affiliation: Hospital Clínico de la Universidad Católica de Chile, Marcoleta 367, Piso 6, Servicio Unidad Coronaria, Santiago-Chile.
authors.forename: Ramón
authors.initials: R
authors.lastname: Corbalán
authors.forename: Carolina
authors.initials: C
authors.lastname: Nazzal
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Prieto
authors.forename: Eduardo
authors.initials: E
authors.lastname: Chávez
authors.forename: Fernando
authors.initials: F
authors.lastname: Lanas
authors.forename: Rubén
authors.initials: R
authors.lastname: Lamich
authors.forename: Jorge
authors.initials: J
authors.lastname: Bartolucci
authors.forename: Rosa
authors.initials: R
authors.lastname: Montaño
authors.forename: Francisco
authors.initials: F
authors.lastname: Cumsille
mesh_terms: D000368:Aged; D002677:Chile / Q000453:epidemiology; D005260:Female; D006333:Heart Failure / Q000401:mortality; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality*; D012307:Risk Factors