Is aspirin (acetylsalicylic acid) still prescribed for prophylactic purposes?

Aspirin Prophylaxis in Cardiovascular Disease: Current Recommendations

Aspirin is still prescribed for prophylactic purposes, but its use has become more selective and targeted based on recent evidence that better balances benefits against bleeding risks.

Secondary Prevention: Strong Recommendation

Aspirin remains strongly recommended for secondary prevention in patients with established cardiovascular disease:

• Patients with prior myocardial infarction, stroke, TIA, or established atherosclerotic disease should receive aspirin 75-81 mg daily indefinitely 1
• For acute myocardial infarction, a dose of 150-325 mg daily is recommended 2
• For other secondary prevention indications (stable angina, prior MI, unstable angina), a dose of 75 mg daily is recommended 2, 1

Primary Prevention: More Selective Approach

Recent guidelines have significantly narrowed the indications for primary prevention:

Age-Based Recommendations:

• Ages 40-59 years: Consider aspirin only if 10-year ASCVD risk ≥10% and no increased bleeding risk 2, 3
• Ages ≥60 years: Aspirin is NOT recommended for routine primary prevention 2, 3
• Ages <40 years: Insufficient evidence to recommend aspirin for primary prevention 2

Risk-Based Algorithm:

1. High CV risk + Low bleeding risk: Consider aspirin 75-100mg daily 1

   • Risk factors supporting use: family history of premature MI, inability to achieve lipid/BP/glucose targets, elevated coronary calcium score 2

2. High CV risk + High bleeding risk: Avoid aspirin, focus on other preventive strategies 1

   • Bleeding risk factors: history of GI bleeding/ulcers, age >70, thrombocytopenia, coagulopathy, CKD, concurrent use of NSAIDs/steroids/anticoagulants 2, 1

3. Low CV risk: Avoid aspirin regardless of bleeding risk 1

Dosing Considerations

• For primary prevention: 75-100 mg daily is the optimal dose 1
• Higher doses (>100 mg) increase bleeding risk without additional cardiovascular benefit 1
• In the US, 81 mg is the preferred dose for most indications 1

Common Pitfalls to Avoid

1. Prescribing aspirin for primary prevention in low-risk individuals - benefits rarely outweigh risks 1
2. Continuing aspirin in patients >70 years for primary prevention - bleeding risk increases substantially with age 2, 1
3. Using doses >100mg daily - increases bleeding risk without additional cardiovascular benefit 1
4. Failing to account for bleeding risk factors when making prescribing decisions 2, 1
5. Prescribing aspirin with uncontrolled hypertension, which may attenuate cardiovascular benefits 1

Special Populations

• Diabetes: Adults >50 years with at least one additional major risk factor may be considered for aspirin 75-162mg daily 2, 1
• Patients on anticoagulants: Significantly increased risk (3-6 fold) of GI bleeding when aspirin is combined with anticoagulants 2
• Patients <21 years: Aspirin is contraindicated due to risk of Reye syndrome 1

Risk Mitigation Strategies

• Consider adding proton pump inhibitors for patients at higher risk of GI bleeding 1
• Regular reassessment of cardiovascular and bleeding risk is necessary 1
• Ensure optimal control of other modifiable risk factors (hypertension, lipids, diabetes) 2

The evidence for aspirin in primary prevention has evolved significantly in recent years, with more recent trials showing less overall benefit alongside contemporary preventive treatments like statins and antihypertensives 2. This has led to more cautious recommendations that carefully weigh cardiovascular benefits against bleeding risks.