Background and objective: Although the benefit of aspirin for patients with known cardiovascular disease is well established, the protective effect in primary prevention remains the subject of a controversial discussion. This meta-analysis was undertaken to ascertain whether a risk reduction regarding mortality and/or cardiovascular events can be achievement with aspirin in persons without known cardiovascular disease?
Methods: A systematic literature search for randomized controlled trials and meta-analyses was done.
Results: Six relevant primary trials and three meta-analyses were found. The validity of three of the trials and thus also the meta-analyses was limited by inclusion of patients with known cardiovascular disease. Therapy with aspirin showed no reduction in terms of overall mortality rate or rate of cardiovascular death. In men the primary prevention with aspirin reduced the risk of a non-fatal myocardial infarction with an annual numbers needed to treat of about 670. There was no equivalent effect in women (except for women (3) 65 years). A reduction of stroke events was only seen in the Women's Health Study, which included only female participants. The effect was quite small, the annual numbers needed to treat were about 3890. An equivalent benefit for men was not proven in any of the other trials.
Conclusion: In view of the absence of life prolonging effect and no possibility of determining a definite risk group, that would have a special or accessory effect from a primary prevention with aspirin, there is no indication for such a scheme.