Conclusions
Translating research into practice is difficult. Stopping previously recommended treatments might be particularly difficult because both clinicians and patients must change previously held beliefs. It is known that there is a time lag between the release of recommendations and widespread clinical application; thus it is possible that aspirin use for primary prevention may slow over the next several years. Cancer prevention may create further pressure to increase the use of low-dose aspirin, but it is important to evaluate all-cause mortality in primary prevention studies to determine overall benefit, not just cancer-specific outcomes.
In theory, using aspirin for primary prevention in high-risk individuals makes sense: coronary artery disease exists well before an index event or before it is serendipitously found. Shiffman et al have proposed genetic testing to improve aspirin usage for primary prevention. Their model starts with the assumption that using aspirin for individuals with a ≥10% Framingham risk score for CVD is beneficial, a position not supported by the literature. Without new positive studies related to primary prevention it is difficult to understand ongoing support for aspirin usage in this context.