What is the recommended antiplatelet therapy for patients with coronary artery disease who are not candidates for revascularization?

Antiplatelet Therapy for Coronary Artery Disease Without Revascularization

For patients with acute coronary syndrome (ACS) managed without revascularization, dual antiplatelet therapy (DAPT) with aspirin 81 mg daily plus either clopidogrel 75 mg daily or ticagrelor 90 mg twice daily should be continued for at least 12 months. 1

Clinical Presentation Determines Strategy

Acute Coronary Syndrome (ACS) Without Revascularization

Dual antiplatelet therapy is mandatory for at least 12 months:

• Aspirin 81 mg daily (range 75-100 mg) combined with a P2Y12 inhibitor 1
• P2Y12 inhibitor options:
  • Ticagrelor 90 mg twice daily (preferred for NSTE-ACS based on Class IIa recommendation) 1
  • Clopidogrel 75 mg daily (acceptable alternative) 1

The ACC/AHA guidelines provide Class I, Level of Evidence B-R recommendation that P2Y12 inhibitor therapy (clopidogrel or ticagrelor) should be continued for at least 12 months in ACS patients managed with medical therapy alone. 1 This recommendation is based on the CURE trial, which demonstrated a 2.1% absolute reduction in ischemic events with clopidogrel added to aspirin, though with a 1.0% absolute increase in major bleeding. 1

Ticagrelor is reasonable to prefer over clopidogrel in NSTE-ACS patients managed medically, based on Class IIa evidence from the PLATO trial. 1

Stable Ischemic Heart Disease (SIHD) Without Recent ACS

Single antiplatelet therapy is appropriate:

• Aspirin 75-100 mg daily as monotherapy 1
• Clopidogrel 75 mg daily is an acceptable alternative if aspirin is contraindicated or not tolerated 1

The 2011 AHA/ACCF guidelines recommend aspirin 75-162 mg daily in all patients with coronary artery disease unless contraindicated, with clopidogrel as an alternative for aspirin-intolerant patients. 1 The 2012 ACCP guidelines support long-term single antiplatelet therapy with aspirin 75-100 mg daily or clopidogrel 75 mg daily for established CAD patients beyond one year post-ACS. 1

Duration Beyond 12 Months

Extended DAPT beyond 12 months may be reasonable (Class IIb) in ACS patients who:

• Have tolerated DAPT without bleeding complications
• Are not at high bleeding risk (no prior bleeding on DAPT, no coagulopathy, no oral anticoagulant use) 1

This represents a weaker recommendation reflecting the balance between continued ischemic protection and increased bleeding risk with prolonged therapy.

Critical Pitfalls to Avoid

Do not use prasugrel in medically managed ACS patients without PCI - the evidence for prasugrel is specific to patients undergoing percutaneous coronary intervention, and it carries a Class III (Harm) recommendation in patients with prior stroke or TIA. 1

Do not continue dual antiplatelet therapy indefinitely in stable CAD - after the initial 12-month period post-ACS, transition to single antiplatelet therapy unless there are compelling reasons to continue DAPT based on individual bleeding and ischemic risk assessment. 1

Bleeding risk assessment is mandatory - patients requiring oral anticoagulation, those with history of gastrointestinal bleeding, or those with coagulopathy require careful consideration and potentially shorter DAPT duration or single antiplatelet therapy. 1

Special Considerations

STEMI patients treated with fibrinolytic therapy require clopidogrel 75 mg daily for a minimum of 14 days (Class I, Level A) and ideally at least 12 months when combined with aspirin. 1

Aspirin dosing matters - the recommended dose is 81 mg daily (range 75-100 mg) when used in DAPT, as higher doses increase bleeding risk without additional efficacy. 1