title: Aspirin versus heparin to prevent myocardial infarction during the acute phase of unstable angina.
abstract: BACKGROUND
  Antiplatelet therapy with aspirin and antithrombotic therapy with heparin both prevent the complications of unstable angina; however, no definitive data exist on the relative clinical efficacy of the two drugs.
  
  
  RESULTS
  Aspirin (325 mg bid) or heparin (5000-U intravenous bolus followed by a perfusion titrated to the APTT) were compared in a double-blind randomized trial of 484 patients in two cohorts enrolled sequentially. The study was initiated at admission to hospital at a mean of 8.3 +/- 7.8 hours after the last episode of pain. End points were assessed 5.7 +/- 3.3 days later, when the decision for long-term management was made. Myocardial infarction occurred in 2 (0.8%) of the 240 patients randomized to heparin and in 9 (3.7%) of the 244 randomized to aspirin (P = .035), an odds ratio of 0.22 and a risk difference of 2.9% (95% confidence limits, 0.3% to 5.6%) with heparin. The only death resulted from a myocardial infarction in an aspirin patient. Survival curves with Cox logistic regression analysis showed that the improvement in survival without myocardial infarction with heparin (P = .035) was independent of other baseline characteristics.
  
  
  CONCLUSIONS
  This study documents that heparin prevents myocardial infarction better than aspirin during the acute phase of unstable angina.
authors.affiliation: Department of Medicine, Montreal Heart Institute, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Théroux
authors.forename: D
authors.initials: D
authors.lastname: Waters
authors.forename: S
authors.initials: S
authors.lastname: Qiu
authors.forename: J
authors.initials: J
authors.lastname: McCans
authors.forename: P
authors.initials: P
authors.lastname: de Guise
authors.forename: M
authors.initials: M
authors.lastname: Juneau
mesh_terms: D000208:Acute Disease; D000789:Angina, Unstable / Q000150:complications / Q000188:drug therapy*; D001241:Aspirin / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005163:Factor Analysis, Statistical; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology / Q000517:prevention & control*
chemical_list: D006493:Heparin; D001241:Aspirin