[Primary prevention with aspirin].

The benefit of acetylsalicylic acid and other antiplatelet drugs in secondary prevention is well established, however it use in primary prevention continues to be controversial. On the one hand, the benefit obtained is very near the potential damage arising from its use (mainly gastrointestinal bleeding), and on the other, the net benefit is less, given that its aim is to prevent the occurrence of vascular events in situations with a lower baseline risk. Antiplatelet treatment with aspirin in primary prevention has been evaluated in clinical trials and several meta-analyses, comparing its efficacy with a placebo, and with results noted for their heterogeneity. The mechanisms of action of different antiplatelet drugs, as well as the existing evidence with aspirin in primary prevention, the directions for its use by different Scientific Societies, and the cost/benefit of the intervention are reviewed.