Background: Increased doses of antiplatelet therapy have been proposed to overcome the variability of response. However, the chronic dose of aspirin after DES remains controversial.
Methods and results: We assessed in a prospective and randomized study the benefit of higher dose of aspirin, in association with clopidogrel, on aspirin response and non COX-specific platelet testing in patients receiving Drug Eluting Stent (DES) for stable angina pectoris. 50 consecutive patients receiving DES for stable angina pectoris were prospectively included. They received loading dose of 250 mg aspirin and 600 mg clopidogrel and antiplatelet response was assessed with Arachidonic Acid-induced aggregation (AA-Ag) and ADP-induced aggregation (ADP-Ag) for aspirin and clopidogrel response respectively. Patients were randomized to either 75 or 160 mg of aspirin with 150 mg clopidogrel and platelet testing were repeated one month after hospital discharge. The two groups (aspirin "75 mg" or "160 mg") had no difference for aspirin response: AA-Ag (5.2 +/- 1.7% vs 6 +/- 2%, p = 0.75) and non COX-specific pathway testing: ADP-Ag (47 +/- 3% vs 49 +/- 4%, p = 0.61).
Conclusion: The present study did not show any benefit of higher dose of aspirin neither on aspirin responsiveness, nor on inhibition of non COX-specific pathway. These data does not support use of higher dose than 75 mg of aspirin in association with clopidogrel in patients receiving DES, especially while higher doses have been associated with increased bleeding risk.