Recommended Aspirin Dose for Cardiovascular Disease
For adults with established cardiovascular disease, use aspirin 75-100 mg daily for long-term secondary prevention. 1
Secondary Prevention (Established CVD)
The optimal dose is 75-100 mg daily, which provides equivalent cardiovascular protection to higher doses while minimizing bleeding complications. 1, 2 In the United States, the most commonly available low-dose formulation is 81 mg, which falls within this recommended range. 1
Key Evidence Supporting This Dose:
The American College of Chest Physicians (2012) 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 (2019,2023) 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. 1
The ADAPTABLE trial (2023) 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. 1
Why Not 150 mg?
There is no evidence that 150 mg provides additional cardiovascular benefit over 75-100 mg daily, but it does increase bleeding risk. 1 All major guidelines consistently recommend the 75-100 mg range because:
- Higher doses (>100 mg) increase gastrointestinal bleeding risk without proportional cardiovascular benefit 1
- 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 1
Acute Coronary Syndrome Exception
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, 3 The loading dose should be chewed (non-enteric coated) to achieve rapid antiplatelet effect. 3
Primary Prevention Context
For primary prevention in high-risk patients (10-year CVD risk ≥10%), the recommended dose is also 75-162 mg daily, though recent evidence suggests the net benefit is small and must be carefully weighed against bleeding risk. 1, 4 For adults ≥60 years, aspirin is not recommended for primary prevention due to bleeding risks outweighing benefits. 4
Bleeding Risk Considerations
Major bleeding occurs at approximately 5 per 1,000 patients per year with aspirin therapy. 1 The risk increases with:
- Doses >100 mg daily 1
- Age >70 years 1
- Uncontrolled hypertension 2
- Concurrent anticoagulation or NSAIDs 2
- History of gastrointestinal bleeding or ulcers 2
Common Pitfalls to Avoid
- Do not use 150 mg routinely - this dose falls outside guideline recommendations and increases bleeding risk without additional cardiovascular benefit 1
- Do not use enteric-coated aspirin for acute loading doses - it delays absorption and antiplatelet effect 3
- Do not prescribe higher doses assuming better efficacy - the dose-response relationship plateaus at 75-100 mg for cardiovascular protection 1
Alternative for Aspirin Allergy
For patients with documented aspirin allergy, substitute clopidogrel 75 mg daily. 1, 2