Is aspirin underused in myocardial infarction?

This article reviews the relevant published literature in order to assess whether aspirin (acetylsalicylic acid; ASA) is underused in myocardial infarction (MI), taking into account: (i) the evidence of efficacy and safety from clinical trials; (ii) authoritative recommendations about its use; and (iii) published drug-utilisation studies. The use of low-dosage aspirin in the acute phase of MI, and as secondary prevention, should be recommended to all patients who do not have contraindications to the drug. This is a solid evidence-based recommendation with potential benefits that are, at least, similar to those obtained with other standard treatments. As this treatment is well tolerated and inexpensive, it is also assumed that net savings can be achieved. No conventionally used prophylactic aspirin regimen seems to be free from the risk of serious gastrointestinal toxicity. This is especially important in primary prevention, in which the benefits are small; there is, as yet, no clear evidence that aspirin is indicated for routine use in patients at low risk of occlusive vascular events. We have identified 21 published drug-utilisation studies, and the potential underuse of aspirin in MI was not properly assessed in most of them. In these studies, fairly high aspirin prescription rates were usually documented. However, it seems clear that there is room for improvement, and that a significant proportion of patients who could have benefited from aspirin did not receive it or received less well-studied and more costly drugs. The prescription rates for other drugs with proven efficacy have been lower, and the potential underuse greater, than those documented for aspirin.