Abstract: Objective To investigate aspirin resistance (AR) in the aspirin-treated patients with coronary artery disease, and further to evaluate the clinical characteristics of them.Methods We prospectively enrolled 102 patients with coronary artery disease on aspirin ( 100 mg/d for ≥2 weeks ) with no other anti-platelet agents. We tested for AR by optical platelet aggregation (PAG) using ADP and AA plasma and urine thromboxane B₂ (TXB₂) concentration were measured by TXB₂ kits. AR was defined as a most PAG of ≥50% with ADP and ≥30% with AA.Results Of the patients studied, 13 (12.7%) were AR. The PAG of AR group was higher than AS group (P<0.01). Urine TXB₂ of AR group was higher than AS group. Plasma TXB₂ was no statistical diversity between groups. The hs-CRP of group with high TXB₂ is higher than the hs-CRP of group with low TXB₂.Conclusion This study detect 12.7% AR in 102 cases aspirin-treated patients with coronary artery disease.

Key words: coronary artery disease, aspirin resistance, platelet aggregation, thromboxane B_ 2