Effect of aspirin on mortality in the primary prevention of cardiovascular disease

Am J Med. 2011 Jul;124(7):621-9. doi: 10.1016/j.amjmed.2011.01.018. Epub 2011 May 17.


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.

Conclusion: Aspirin prevents deaths, myocardial infarction, and ischemic stroke, and increases hemorrhagic stroke and major bleeding when used in the primary prevention of cardiovascular disease.

Publication types

  • Meta-Analysis

MeSH terms

  • Adult
  • Aged
  • Aspirin / administration & dosage
  • Aspirin / adverse effects
  • Aspirin / pharmacology*
  • Cardiovascular Agents / administration & dosage
  • Cardiovascular Agents / adverse effects
  • Cardiovascular Agents / pharmacology*
  • Cause of Death*
  • Female
  • Gastrointestinal Hemorrhage / chemically induced
  • Gastrointestinal Hemorrhage / epidemiology
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Myocardial Infarction / epidemiology*
  • Myocardial Infarction / mortality
  • Myocardial Infarction / prevention & control*
  • Primary Prevention / methods*
  • Randomized Controlled Trials as Topic
  • Risk Assessment
  • Stroke / epidemiology*
  • Stroke / mortality
  • Stroke / prevention & control*


  • Cardiovascular Agents
  • Aspirin