Indications for Single Antiplatelet Therapy

Primary Prevention

• The American College of Chest Physicians recommends low-dose aspirin 75-100 mg daily for primary prevention in persons aged 50 years or older without symptomatic cardiovascular disease (Grade 2B) 1
• The benefit of low-dose aspirin is most pronounced when taken over 10 years, with a slight reduction in total mortality regardless of cardiovascular risk profile 1

Established Coronary Artery Disease

• The American College of Chest Physicians recommends long-term SAPT with aspirin 75-100 mg daily or clopidogrel 75 mg daily for patients with established coronary artery disease (Grade 1A) 1, 3
• SAPT is preferred over dual antiplatelet therapy in patients with established coronary artery disease (Grade 2B) 1, 3

Post-Acute Coronary Syndrome and Stent Placement

• The American College of Chest Physicians recommends SAPT over continued dual antiplatelet therapy after the first year of an acute coronary syndrome (Grade 1B) 1, 4
• For patients with bare-metal stents, SAPT is recommended after the first month of dual antiplatelet therapy 1, 4
• For patients with drug-eluting stents, SAPT is recommended after 3-6 months of dual antiplatelet therapy 1, 4

Peripheral Arterial Disease (PAD)

• The American College of Cardiology recommends SAPT to reduce the risk of major adverse cardiovascular events in patients with symptomatic PAD (Grade 1A) 2, 5, 6, 7
• Options for SAPT in symptomatic PAD include clopidogrel 75 mg daily (Grade 1B-R) and aspirin 75-325 mg daily (Grade 1C-LD) 2, 5, 7

Cerebrovascular Disease

• SAPT is indicated for long-term secondary prevention in patients with non-cardioembolic ischemic stroke or TIA who do not require anticoagulation 8
• Options for SAPT in cerebrovascular disease include aspirin 81-325 mg daily, clopidogrel 75 mg daily, or aspirin + dipyridamole 25/200 mg daily 8

Special Considerations

• The American College of Chest Physicians recommends SAPT with clopidogrel for patients with anterior MI and LV thrombus who do not undergo stenting, after 3 months of warfarin plus aspirin, and subsequent dual antiplatelet therapy for up to 12 months 3
• SAPT with clopidogrel has shown improved efficacy compared to aspirin for MACE prevention in PAD patients, with similar bleeding rates 2, 5, 7

Common Pitfalls to Avoid

• Continuing dual antiplatelet therapy beyond 12 months after ACS or stent placement without specific indications increases bleeding risk without additional benefit 1, 4
• Using full-intensity oral anticoagulation in PAD patients without another indication should be avoided as it increases bleeding risk without benefit (Grade 3: Harm, A) 2, 5, 6, 7