This is from the website of the American Heart Association
AHA/ACC Guidelines for Secondary Prevention for Patients With Coronary and Other Atherosclerotic Vascular Disease: 2006 Update
ANTIPLATELET AGENTS/ ANTICOAGULANTS: • Start aspirin
75 to 162 mg/d and continue indefinitely in all patients unless contraindicated.
For patients undergoing coronary artery
bypass grafting, aspirin should be started within 48 hours after surgery to reduce saphenous vein graft closure. Dosing
regimens ranging from 100 to 325 mg/d appear to be efficacious. Doses higher than 162 mg/d can be continued for up to 1 year.
Patients who have undergone percutaneous coronary intervention
placement should initially receive higher-dose aspirin at 325 mg/d for 1 month for bare metal stent, 3 months for sirolimus-eluting stent, and 6 months for paclitaxel-eluting stent.