Assessment of platelet function and resistance to aspirin and clopidogrel in patients with peripheral arterial disease undergoing percutaneous transluminal angioplasty

Introduction: Analysis of platelet function, acetylsalicylic acid (ASA) and clopidogrel resistance in patients with peripheral arterial disease (PAD) undergoing percutaneous transluminal angioplasty (PTA), the impact of procedure on this phenomenon, connection with diabetes, hypertension, smoking. Material and methods: The study included 72 patients, with a group of patients taking ASA on a permanent basis and a group of patients in whom treatment was implemented after the procedure. Patients were also divided according to the antiplatelet therapy applied, either double-therapy, or ASA monotherapy. Daily doses were 75 mg. Three methods were used for the evaluation of the platelet function: IVY bleeding time, cytometric evaluation of platelet surface antigen (CD62p and CD63) expression and hemostasis measurement by PFA-200®. Results: In the PFA-200 analysis, ASA resistance was found in 37.8% (64.7% were tobacco smokers) before surgery. Patients not taking ASA before, after PTA and first dose of ASA presented resistance in 63%. The first dose of clopidogrel after surgery was associated with resistance in 73.7%. Significant differences in the expression of CD62p and CD63 markers before and after PTA were observed. According to IVY method, aspirin resistance was found in 40% of patients permanently receiving ASA. Conclusions: Patients with PAD who undergo PTA are resistant to ASA in 40%, smoking is associated with this phenomenon. PTA increases the expression of CD62P and CD63, and thus the platelet activation, which is not adequately prevented by antiplatelet drugs at a dose of 75 mg. Dual antiplatelet therapy reduces the activation of thrombocytes more than the monotherapy of ASA.