title: Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acute myocardial infarction having primary percutaneous coronary intervention: observational study.
abstract: OBJECTIVE
  To evaluate the relation of symptom onset to balloon time and door to balloon time with long term clinical outcome in patients with ST segment elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention.
  
  
  METHODS
  Observation of large cohort of patients with acute myocardial infarction.
  
  
  METHODS
  26 tertiary hospitals in Japan.
  
  
  METHODS
  3391 patients with STEMI who had primary percutaneous coronary intervention within 24 hours of symptom onset.
  
  
  METHODS
  Composite of death and congestive heart failure, compared by onset to balloon time and door to balloon time.
  
  
  RESULTS
  Compared with an onset to balloon time greater than 3 hours, a time of less than 3 hours was associated with a lower incidence of a composite of death and congestive heart failure (13.5% (123/964) v 19.2% (429/2427), P<0.001; relative risk reduction 29.7%). After adjustment for confounders, a short onset to balloon time was independently associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.70, 95% confidence interval 0.56 to 0.88; P=0.002). However, no significant difference was found in the incidence of a composite of death and congestive heart failure between the two groups of patients with short (≤90 minutes) and long (>90 minutes) door to balloon time (16.7% (270/1671) v 18.4% (282/1720), P=0.54; relative risk reduction 9.2%). After adjustment for confounders, no significant difference was seen in the risk of the composite endpoint between the two groups of patients with short and long door to balloon time (adjusted hazard ratio: 0.98, 0.78 to 1.24: P=0.87). A door to balloon time of less than 90 minutes was associated with a lower incidence of a composite of death and congestive heart failure in patients who presented within 2 hours of symptom onset (11.9% (74/883) v 18.1% (147/655), P=0.01; relative risk reduction 34.3%) but not in patients who presented later (19.7% (196/788) v 18.7% (135/1065), P=0.44; -5.3%). Short door to balloon time was independently associated with a lower risk of a composite of death and congestive heart failure in patients with early presentation (adjusted hazard ratio 0.58, 0.38 to 0.87; P=0.009) but not in patients with delayed presentation (1.57, 1.12 to 2.18; P=0.008). A significant interaction was seen between door to balloon time and time to presentation (interaction P=0.01).
  
  
  CONCLUSIONS
  Short onset to balloon time was associated with better 3 year clinical outcome in patients with STEMI having primary percutaneous coronary intervention, whereas the benefit of short door to balloon time was limited to patients who presented early. Efforts to minimise onset to balloon time, including reduction of patient related delay, should be recommended to improve clinical outcome in STEMI patients.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shiomi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Furukawa
authors.forename: Akira
authors.initials: A
authors.lastname: Nakano
authors.forename: Shinichi
authors.initials: S
authors.lastname: Shirai
authors.forename: Ryoji
authors.initials: R
authors.lastname: Taniguchi
authors.forename: Kyohei
authors.initials: K
authors.lastname: Yamaji
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nagao
authors.forename: Tamaki
authors.initials: T
authors.lastname: Suyama
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Mitsuoka
authors.forename: Makoto
authors.initials: M
authors.lastname: Araki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takashima
authors.forename: Tetsu
authors.initials: T
authors.lastname: Mizoguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Eisawa
authors.forename: Seigo
authors.initials: S
authors.lastname: Sugiyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D015331:Cohort Studies; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D016016:Proportional Hazards Models; D013997:Time Factors; D016896:Treatment Outcome