Clinical question: Does aspirin prevent cardiovascular events in patients with peripheral artery disease (PAD)?

Background: Evidence that aspirin decreases risk of cardiovascular events in patients with symptomatic coronary artery disease and cerebrovascular disease has led to a recommendation of aspirin as secondary prevention in PAD. Evidence for its efficacy in this context is not established.

Study design: Meta-analysis.

Setting: Multiple study sites.

Synopsis: The investigators looked at 18 randomized controlled trials involving 5,269 participants, 2,823 of whom received aspirin, including 1,516 as monotherapy and 2,446 controls. The primary endpoint investigated was cardiovascular events.

This meta-analysis did not show a statistical benefit in cardiovascular event reduction (8.9% vs. 11%) in aspirin therapy in patients with peripheral artery disease, but it did show a decrease in the secondary endpoint of nonfatal strokes. A subset analysis of aspirin monotherapy versus placebo showed a nonsignificant decrease in the primary endpoint.

The studies had a short timeline with few cardiovascular events, so conclusions cannot be drawn about longer timeframes. Furthermore, some of the included studies were not designed to measure cardiovascular events. Finally, the study was not powered to detect differences less than 25%.

Bottom line: In patients with PAD, aspirin might not decrease the incidence of cardiovascular events.

Citation: Berger JT, Krantz MJ, Kittelson JM, Hiatt WR. Aspirin for the prevention of cardiovascular events in patients with peripheral artery disease: a meta-analysis of randomized trials. JAMA. 2009;301(18):1909-1919.

—Reviewed for The Hospitalist by Steven Deitelzweig, MD, MMM, FHM; Frank Wharton, MD, FACP; Renee Meadows, MD, FHM; Srinivas Vuppala, MD; Kevin Hude, MD; Doris Lin, MD; Damodar Kumbala, MD, Department of Hospital Medicine, Ochsner Medical Center, New Orleans