No Clear Benefit for Aspirin in Primary Prevention of Cardiovascular Disease

In patients with histories of symptomatic occlusive vascular disease, aspirin’s ability to prevent future adverse cardiovascular events significantly outweighs its association with elevated risks for major bleeding. However, use of aspirin for primary prevention of occlusive vascular disease remains controversial; prospective trials and meta-analyses have shown no overall net benefit for aspirin and have lacked power to identify subgroups of patients in which aspirin’s benefits might significantly outweigh its risks.

To overcome these limitations, investigators pooled individual patient data from six large prospective primary prevention trials of aspirin, in which 95,000 patients without diabetes and without histories of occlusive vascular d…