Bowman L, et al. - Aspirin use has been shown to decrease the risk of occlusive vascular events, but increase the risk of bleeding, so researchers assessed the benefits and hazards of aspirin use for the prevention of first cardiovascular events in patients with diabetes. They observed that use of aspirin prevented serious vascular events (ie, myocardial infarction, stroke or transient ischemic attack, or death from any vascular cause, excluding any confirmed intracranial hemorrhage) in patients with diabetes and no apparent cardiovascular disease at trial entry, but it also caused major bleeding events (ie, intracranial hemorrhage, sight-threatening bleeding event in the eye, gastrointestinal bleeding, or other serious bleeding). It was noted that the absolute benefits were mostly offset by the hazard of bleeding.

Methods

• For this investigation, adults who had diabetes but no apparent cardiovascular disease were randomized to aspirin at a daily dose of 100 mg or matching placebo.
• The first serious vascular event was the primary efficacy outcome.
• The first major bleeding event was the primary safety outcome.
• Gastrointestinal tract cancer was included as a secondary outcome.

Results

• An aggregate of 15,480 study participants were randomized.
• Serious vascular events occurred in a significantly lower percentage of participants in the aspirin group vs the placebo group (658 participants [8.5%] vs 743 [9.6%]; rate ratio, 0.88; 95% confidence interval [CI], 0.79 to 0.97; P=0.01) during a mean follow-up of 7.4 years.
• Findings revealed that major bleeding events occurred in 314 study participants (4.1%) in the aspirin group, as compared with 245 (3.2%) in the placebo group (rate ratio, 1.29; 95% CI, 1.09 to 1.52; P=0.003); most of the excess being gastrointestinal bleeding and other extracranial bleeding.
• No significant difference was found between the aspirin group and the placebo group in the incidence of gastrointestinal tract cancer (157 participants [2.0%] and 158 [2.0%], respectively) or all cancers (897 [11.6%] and 887 [11.5%]).