title: Effect of aspirin on mortality in the primary prevention of cardiovascular disease.
abstract: OBJECTIVE
  The lack of a mortality benefit of aspirin in prior meta-analyses of primary prevention trials of cardiovascular disease has contributed to uncertainty about the balance of benefits and risks of aspirin in primary prevention. We performed an updated meta-analysis of randomized controlled trials of aspirin to obtain best estimates of the effect of aspirin on mortality in primary prevention.
  
  
  METHODS
  Eligible articles were identified by searches of electronic databases and reference lists. Outcomes of interest were all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and bleeding. Data were pooled from individual trials using the DerSimonian-Laird random-effects model, and results are presented as relative risk (RR) and 95% confidence intervals (CIs).
  
  
  RESULTS
  Nine randomized controlled trials enrolling 100,076 participants were included. Aspirin reduced all-cause mortality (RR 0.94; 95% CI, 0.88-1.00), myocardial infarction (RR 0.83; 95% CI, 0.69-1.00), ischemic stroke (RR 0.86; 95% CI, 0.75-0.98), and the composite of myocardial infarction, stroke, or cardiovascular death (RR 0.88; 95% CI, 0.83-0.94), but did not reduce cardiovascular mortality (RR 0.96; 95% CI, 0.84-1.09). Aspirin increased the risk of hemorrhagic stroke (RR 1.36; 95% CI, 1.01-1.82), major bleeding (RR 1.66; 95% CI, 1.41-1.95), and gastrointestinal bleeding (RR 1.37; 95% CI, 1.15-1.62). A lack of availability of patient-level data precluded exploration of benefits and risks of aspirin in key subgroups.
  
  
  CONCLUSIONS
  Aspirin prevents deaths, myocardial infarction, and ischemic stroke, and increases hemorrhagic stroke and major bleeding when used in the primary prevention of cardiovascular disease.
authors: Haematology Unit, Queensland Pathology and Department of Internal Medicine, Prince Charles Hospital, Brisbane, Australia.
authors: Nina
authors: N
authors: Raju
authors: Magdalena
authors: M
authors: Sobieraj-Teague
authors: Jack
authors: J
authors: Hirsh
authors: Martin
authors: M
authors: O'Donnell
authors: John
authors: J
authors: Eikelboom