Aspirin Therapy for NSTEMI

Initial and Maintenance Dosing

• The American Heart Association recommends an initial dose of 162-325 mg of aspirin, followed by a maintenance dose of 75-162 mg daily indefinitely for patients with NSTEMI 1, 2, 3
• The American College of Cardiology recommends that after the initial loading dose, maintenance therapy with 75-162 mg daily should be continued indefinitely for patients with NSTEMI 2, 3, 4
• Lower maintenance doses (75-100 mg) are preferred over higher doses due to similar efficacy with lower bleeding risk, according to the American Heart Association 1

Dosing Based on Treatment Strategy

• For medically managed NSTEMI patients, the American Heart Association recommends ASA 75-162 mg daily indefinitely, with a Level of Evidence: A 3, 4
• For NSTEMI treated with bare-metal stent, the American College of Cardiology recommends initial ASA 162-325 mg daily for at least 1 month, then continued indefinitely at 75-162 mg daily 2, 3
• For NSTEMI treated with drug-eluting stent, the American Heart Association recommends initial ASA 162-325 mg daily for at least 3 months after sirolimus-eluting stent or 6 months after paclitaxel-eluting stent, then continued indefinitely at 75-162 mg daily 3, 7

Special Considerations

• For patients with increased bleeding risk, a lower initial ASA dose of 75-162 mg daily after PCI is reasonable, with a Level of Evidence: C, according to the American College of Cardiology 5, 8
• A dose-dependent increase in bleeding has been observed with aspirin, with 2.0% with <100 mg, 2.3% with 100-200 mg, and 4.0% with >200 mg daily, as reported by the American Heart Association 1
• For ASA-allergic patients, the American College of Cardiology recommends using clopidogrel alone or trying ASA desensitization 5, 6