What is the recommended daily dose of aspirin (acetylsalicylic acid) for patients with coronary artery disease (CAD)?

Recommended Daily Aspirin Dose for Coronary Artery Disease

For patients with coronary artery disease (CAD), a daily aspirin dose of 81 mg (range 75-100 mg) is recommended as the optimal maintenance dose. 1

Evidence-Based Rationale

The 2016 ACC/AHA guidelines provide clear recommendations regarding aspirin dosing for patients with CAD:

• Low-dose aspirin (81 mg daily, range 75-100 mg) is consistently recommended across all CAD patient populations 1
• This dosage provides optimal antithrombotic protection while minimizing bleeding risks 1, 2
• Higher doses do not provide additional cardiovascular protection but increase bleeding risk 3, 4

Specific Recommendations by Clinical Scenario

Stable CAD

• Aspirin 81 mg (75-100 mg) daily is recommended for lifelong therapy 1
• For patients intolerant to aspirin, clopidogrel 75 mg daily is recommended as an alternative 1

Post-Myocardial Infarction/ACS

• Aspirin 81 mg (75-100 mg) daily is recommended as part of dual antiplatelet therapy (DAPT) for at least 12 months 1
• After completion of DAPT, aspirin 81 mg should be continued indefinitely 1

Post-PCI with Stent Placement

• Aspirin 81 mg (75-100 mg) daily plus a P2Y12 inhibitor (typically clopidogrel 75 mg daily) for:
  • At least 6 months after drug-eluting stent (DES) for stable CAD 1
  • At least 12 months after stenting for ACS 1
  • After completion of DAPT, aspirin 81 mg should be continued indefinitely 1

Post-CABG

• Aspirin 81 mg (75-100 mg) daily is recommended to be started within 6 hours after surgery 1
• This dosage is effective in reducing saphenous vein graft closure 1

Important Considerations

Bleeding Risk

• Higher aspirin doses (>100 mg) increase bleeding risk without providing additional ischemic protection 3, 4
• In patients requiring triple therapy (aspirin + P2Y12 inhibitor + oral anticoagulant), low-dose aspirin (≤100 mg daily) is particularly important to minimize bleeding risk 1

Special Populations

• Elderly patients (>70 years): Lower aspirin dose (81 mg) is reasonable to minimize bleeding risk while maintaining efficacy 2
• Patients with high bleeding risk: Consider shorter duration of DAPT but maintain the 81 mg aspirin dose 1

Common Pitfalls to Avoid

1. Using higher doses unnecessarily: The CURE study demonstrated that aspirin doses >100 mg increased bleeding without improving efficacy 3
2. Abrupt discontinuation: This can trigger rebound thrombotic events in patients with established CAD 2
3. Failure to use gastroprotection: Consider proton pump inhibitors in patients at high risk for gastrointestinal bleeding 1

Algorithm for Aspirin Dosing in CAD

1. For all CAD patients: Start with aspirin 81 mg daily
2. Assess bleeding risk (prior bleeding, age >70, concomitant anticoagulants)
3. If bleeding occurs or risk is very high: Maintain 81 mg dose but consider shorter DAPT duration
4. If patient is aspirin intolerant: Switch to clopidogrel 75 mg daily

The evidence consistently supports that 81 mg (75-100 mg) daily aspirin provides the optimal balance of antithrombotic efficacy and bleeding risk in patients with CAD.