Uncertain benefit of aspirin for peripheral artery disease

Is aspirin useful in reducing the risk of cardiovascular events in adults with peripheral artery disease?

Aspirin alone or in combination with dipyridamole significantly reduces the risk of nonfatal stroke in adults with peripheral artery disease (PAD). There was no significant association between aspirin alone or aspirin with dipyridamole in reducing the risk of myocardial infarction, cardiovascular mortality, major bleeding events, or all-cause mortality. (LOE = 1a)

Berger JS, 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.  [PMID:19436018]

Meta-analysis (randomized controlled trials)

Government

Various (meta-analysis)

Various guidelines recommend aspirin for patients with PAD. These investigators thoroughly searched multiple databases including MEDLINE, EMBASE, The Cochrane Registry of Controlled Trials, Science Citation Index, bibliographies of retrieved trials, and abstracts from major scientific meetings for randomized trials investigating the effect of aspirin alone or aspirin with dipyridamole on cardiovascular event rates in patients with PAD. Two individuals independently evaluated potential studies for inclusion criteria and methodologic quality. Discrepancies were resolved by consensus agreement. Study quality was assessed using standard Jadad criteria with scores ranging from 2 to 5 (0 = low quality; 5 = high quality). Eighteen trials (n = 5269) met inclusion criteria with follow-up durations of 10 days to 6.7 years. Aspirin doses ranged from 100 mg per day to 1500 mg per day. Treatment with aspirin alone or with dipyridamole was associated with a statistically significant reduction in the risk of nonfatal stroke (number needed to treat = 79; 95% CI, 47-234). There was no significant association between aspirin alone or aspirin with dipyridamole in reducing the risk of myocardial infarction, cardiovascular mortality, major bleeding events, or all-cause mortality. Formal analyses found no evidence for publication bias or significant heterogeneity of the results.