Aspirin Dosage for Cardiovascular Disease Prevention

Secondary Prevention

The American College of Chest Physicians recommends aspirin 75-100 mg daily for patients with established coronary artery disease, including those >1 year post-acute coronary syndrome, with prior revascularization, or documented coronary stenosis >50% 1
The American Diabetes Association recommends aspirin 75-162 mg/day for secondary prevention in patients with atherosclerotic cardiovascular disease, emphasizing that doses in the 75-100 mg range are optimal 2, 3, 4
The ADAPTABLE trial demonstrated no significant differences in cardiovascular events or major bleeding between 81 mg and 325 mg daily doses in patients with established cardiovascular disease, supporting use of the lower dose 4

Higher doses (>100 mg) increase gastrointestinal bleeding risk without proportional cardiovascular benefit 2, 4
Meta-analyses show doses from 75 mg to >1500 mg provide similar benefits on myocardial infarction, stroke, and cardiovascular death in secondary prevention 1
Using the lowest effective dose (75-81 mg) minimizes adverse effects while maintaining full efficacy 4

During acute coronary syndrome or acute myocardial infarction, use a loading dose of 162-325 mg initially, followed by 75-100 mg daily for maintenance 1

For primary prevention in high-risk patients (10-year CVD risk ≥10%), the recommended dose is also 75-162 mg daily 2, 3

Major bleeding occurs at approximately 5 per 1,000 patients per year with aspirin therapy 2, 3
The risk increases with doses >100 mg daily 4, age >70 years 3, 4, uncontrolled hypertension 5, concurrent anticoagulation or NSAIDs 5, and history of gastrointestinal bleeding or ulcers 5

For patients with documented aspirin allergy, substitute clopidogrel 75 mg daily 2, 3, 5