Is aspirin therapy advisable for patients with minimal coronary artery disease?

Aspirin for Minimal Coronary Artery Disease

Yes, aspirin 75-100 mg daily is recommended for patients with minimal coronary artery disease, defined as significant obstructive CAD on imaging, even without prior myocardial infarction or revascularization. 1

Guideline-Based Recommendation

The 2024 European Society of Cardiology guidelines represent the most current evidence and explicitly state that in patients without prior MI or revascularization but with evidence of significant obstructive CAD, aspirin 75-100 mg daily is recommended lifelong (Class I, Level B). 1 This is a stronger recommendation than previous iterations, which only suggested aspirin "may be considered" in this population. 1

The American College of Chest Physicians similarly recommends long-term low-dose aspirin (75-100 mg/d) for patients with established coronary artery disease, which they define to include coronary stenoses >50% by coronary angiogram, even in patients without prior acute coronary syndrome or revascularization (Grade 1A). 1

Supporting Evidence for Efficacy

A meta-analysis of low-dose aspirin in stable cardiovascular disease demonstrated that treatment of 1000 patients for 33 months would prevent 33 cardiovascular events, 12 nonfatal MIs, 25 nonfatal strokes, and 14 deaths. 2 The therapy showed a 21% reduction in cardiovascular events, 26% reduction in nonfatal MI, and 13% reduction in all-cause mortality. 2

Bleeding Risk Considerations

The primary concern with aspirin is major bleeding, which occurred in approximately 9 additional patients per 1000 treated over 33 months in stable disease. 2 This bleeding risk must be weighed against cardiovascular benefit, but in patients with documented obstructive CAD, the benefit clearly outweighs the risk. 1

Contraindications to aspirin include:

• Active bleeding or bleeding tendency 3
• Aspirin allergy 3
• Concurrent anticoagulant therapy (requires careful consideration) 3
• Recent gastrointestinal bleeding 3
• Uncontrolled hypertension 3

Optimal Dosing

The recommended dose is 75-100 mg daily (81 mg in the US). 1, 3 This low-dose regimen provides maximal cardiovascular protection while minimizing bleeding risk. 1

Alternative for Aspirin Intolerance

Clopidogrel 75 mg daily is recommended as a safe and effective alternative to aspirin monotherapy in patients who cannot tolerate aspirin. 1 This represents a Class I recommendation with Level A evidence. 1

Clinical Pitfalls to Avoid

• Do not withhold aspirin simply because the patient has not had an MI or revascularization—documented obstructive CAD on imaging is sufficient indication. 1
• Do not use higher doses—there is no additional benefit beyond 75-100 mg daily, and bleeding risk increases. 1
• Do not confuse this with primary prevention—patients with documented obstructive CAD have established disease requiring secondary prevention, not primary prevention. 1
• Ensure blood pressure is controlled before initiating aspirin to minimize bleeding risk. 3