Dual Antiplatelet Therapy in NSTEMI

Introduction to Dual Antiplatelet Therapy

• The American College of Cardiology recommends aspirin administration as a Class I recommendation for all NSTEMI patients without contraindications as soon as possible after presentation, with a loading dose of 162-325 mg of non-enteric-coated, chewable aspirin, followed by a maintenance dose of 81-325 mg daily 1, 2
• The American College of Cardiology recommends clopidogrel initiation immediately in addition to aspirin for NSTEMI patients, regardless of whether an invasive or conservative strategy is planned, with a loading dose of 300-600 mg, and 600 mg providing more rapid and reliable platelet inhibition, followed by 75 mg daily maintenance 1, 3, 4

Dosing and Duration

• The American Heart Association suggests a loading dose of aspirin as 162-325 mg non-enteric-coated, chewable immediately, then 81 mg daily maintenance 1, 2
• The American College of Cardiology recommends a loading dose of clopidogrel as 600 mg (preferred over 300 mg for faster onset), then 75 mg daily 1, 5
• The American College of Cardiology recommends continuing dual antiplatelet therapy for at least 12 months unless bleeding risk outweighs benefit 1, 4

Special Considerations

• The American College of Cardiology states that sepsis itself is not listed as a contraindication to antiplatelet therapy in NSTEMI guidelines, and the thrombotic risk from NSTEMI must be weighed against bleeding risk 6, 1, 7, 2
• The American Heart Association suggests that if platelet count drops below 50,000/μL, the risk-benefit calculation changes significantly, though this is not explicitly addressed in guidelines, and consultation with hematology may be warranted 4
• The American College of Cardiology recommends that GP IIb/IIIa inhibitors (eptifibatide or tirofiban) may be added for high-risk features, though this further increases bleeding risk and should be used cautiously with thrombocytopenia 6, 1, 4
• The American College of Cardiology states that ticagrelor (180 mg loading, 90 mg twice daily) is preferred over clopidogrel in current guidelines for NSTEMI when available, though bleeding risk is similar 1, 5, 2