title: Impact of aspirin according to type of stable coronary artery disease: insights from a large international cohort.
abstract: BACKGROUND
  Aspirin is recommended in stable coronary artery disease based on myocardial infarction and stroke studies. However, benefit among stable coronary artery disease patients who have not suffered an acute ischemic event is uncertain. The objective of this study was to evaluate the impact of aspirin in stable coronary artery disease. We hypothesized that aspirin's benefit would be attenuated among individuals with stable coronary artery disease but no prior ischemic event.
  
  
  METHODS
  An observational study was conducted from the INternational VErapamil-SR/Trandolapril STudy cohort. Ambulatory patients ≥ 50 years of age with clinically stable coronary artery disease requiring antihypertensive drug therapy (n = 22,576) were classified "ischemic" if they had a history of unstable angina, myocardial infarction, transient ischemic attack, or stroke at the baseline visit. All others were classified "non-ischemic." Aspirin use was updated at each clinic visit and considered as a time-varying covariate in a Cox regression model. The primary outcome was first occurrence of all-cause mortality, myocardial infarction, or stroke.
  
  
  RESULTS
  At baseline, 56.7% of all participants used aspirin, which increased to 69.3% at study close out. Among the "non-ischemic" group (n = 13,091), aspirin was not associated with a reduction in risk (hazard ratio [HR] 1.11; 95% confidence interval [CI], 0.97-1.28; P = .13); however, among the "ischemic" group (n = 9485), aspirin was associated with a reduction in risk (HR 0.87; 95% CI, 0.77-0.99; P = .033).
  
  
  CONCLUSIONS
  In patients with stable coronary artery disease and hypertension, aspirin use was associated with reduced risk for adverse cardiovascular outcomes among those with prior ischemic events. Among patients with no prior ischemic events, aspirin use was not associated with a reduction in risk.
authors.affiliation: North Florida/South Georgia Veterans Health System, Gainesville, Fla; College of Medicine, University of Florida, Gainesville. Electronic address: Anthony.bavry@va.gov.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Bavry
authors.affiliation: College of Pharmacy, University of Florida, Gainesville.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: College of Medicine, University of Florida, Gainesville.
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Handberg
authors.affiliation: College of Medicine, University of Florida, Gainesville; College of Pharmacy, University of Florida, Gainesville.
authors.forename: Rhonda M
authors.initials: RM
authors.lastname: Cooper-DeHoff
authors.affiliation: College of Medicine, University of Florida, Gainesville.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Pepine
mesh_terms: D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D003324:Coronary Artery Disease / Q000150:complications / Q000188:drug therapy* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000517:prevention & control; D017202:Myocardial Ischemia / Q000150:complications / Q000188:drug therapy; D016016:Proportional Hazards Models; D020521:Stroke / Q000517:prevention & control; D016896:Treatment Outcome
chemical_list: D001241:Aspirin
keywords: Adverse cardiovascular events; Aspirin; Coronary artery disease; Ischemic heart disease