Gastrointestinal bleeding during low-dose aspirin administration for prevention of arterial occlusive events. A critical analysis.

Low-dose aspirin has been recommended for primary and secondary prevention of myocardial infarction and for the maintenance of aortocoronary bypass patency. Doses as low as 75 mg/day significantly lessen the risk of stroke or death in patients who experience cerebrovascular and ischemic events. Aspirin in antiinflammatory doses has been associated with gastrointestinal bleeding, and the bleeding potential of even 75 mg aspirin has been established. I assessed the role of low-dose aspirin in gastrointestinal bleeding by combining the results of nine studies that dealt with the prevention of ischemic, thromboembolic, or cerebrovascular events. The combination of the results showed that the occurrence of bleeding was 1.5 times higher in patients treated with low-dose aspirin in doses of 75-325 mg/day as compared with placebo (odds ratio 1.52; 95% CI 1.32-1.75). The monthly probability of gastrointestinal bleeding per 1,000 patients treated with low-dose aspirin ranged between 0 and 2.1.