Yes, you should take low-dose aspirin (75-100 mg daily) lifelong if you have evidence of significant obstructive coronary artery disease on imaging, even without prior stenting.
The 2024 ESC guidelines explicitly recommend aspirin 75-100 mg daily lifelong for patients without prior MI or revascularization but with evidence of significant obstructive CAD (Class I, Level B recommendation) 1. This is a clear, guideline-supported indication for aspirin therapy in your situation.
The Evidence-Based Rationale
Primary Guideline Support
The most recent and authoritative guidance comes from the 2024 ESC chronic coronary syndromes guidelines, which place you in a category requiring lifelong aspirin therapy 1. This recommendation recognizes that visible obstructive CAD on imaging represents established atherosclerotic disease requiring secondary prevention, regardless of whether you've had interventional procedures.
The 2011 AHA/ACCF guidelines similarly recommend aspirin 75-162 mg daily for all patients with coronary artery disease unless contraindicated (Class I, Level A) 2. While older, these guidelines align with current ESC recommendations and have stood the test of time.
Why This Matters for You
Your imaging-confirmed CAD places you at elevated risk for:
- Myocardial infarction
- Stroke
- Cardiovascular death
Meta-analysis data demonstrates that low-dose aspirin in stable cardiovascular disease reduces:
- Cardiovascular events by 21%
- Nonfatal MI by 26%
- Stroke by 25%
- All-cause mortality by 13%
Treating 1000 patients for 33 months prevents 33 cardiovascular events, 12 MIs, 25 strokes, and 14 deaths 3.
Practical Implementation
Dosing: Take 75-100 mg (typically 81 mg in North America) once daily 1, 2.
Alternative if aspirin-intolerant: Clopidogrel 75 mg daily is an acceptable substitute if you cannot tolerate aspirin or have a true aspirin allergy 1, 2.
Critical Caveats and Bleeding Risk Assessment
You should NOT take aspirin if you have:
- Active gastrointestinal bleeding or recent major bleeding
- Severe uncontrolled bleeding disorder
- True aspirin allergy (not just intolerance)
Consider gastric protection with a proton pump inhibitor if you have:
- History of GI bleeding or peptic ulcer disease
- Age ≥65-70 years
- Chronic NSAID or steroid use
- High alcohol consumption
- Combination antithrombotic therapy 1
The increased bleeding risk is real but manageable: aspirin causes approximately 9 major bleeding events per 1000 patients treated over 33 months 3. This risk is substantially outweighed by cardiovascular benefit in patients with established CAD.
Common Pitfalls to Avoid
Don't confuse this with primary prevention: Recent trials (ASPREE, ARRIVE, ASCEND) have shown limited or no benefit for aspirin in people without established cardiovascular disease 4. You have documented obstructive CAD—this is secondary prevention, where aspirin's benefit is well-established.
Don't use high-dose aspirin: Doses above 100 mg daily increase bleeding risk without improving efficacy 1, 5. The 75-100 mg range provides optimal benefit-to-risk ratio.
Don't stop aspirin without medical consultation: Discontinuation in patients with established CAD increases cardiovascular event risk.
The Bottom Line
Your imaging-confirmed obstructive CAD qualifies you for lifelong aspirin therapy according to the highest level of guideline recommendations. The cardiovascular protection substantially outweighs bleeding risk in your situation, provided you don't have specific contraindications. Start aspirin 75-100 mg daily and continue indefinitely, adding gastric protection if you have bleeding risk factors 1.