Monitoring of antiplatelet therapy with the PFA-100® in peripheral angioplasty patients

Background: In patients suffering from peripheral arterial occlusive disease (PAOD) the risk of restenosis after percutaneous transluminal angioplasty ( PTA) might be influenced by platelet mediated factors. Objective: To look for a correlation between the effect of antiplatelet therapy and recurrence of disease after PTA by monitoring platelet function in 3-month intervals by the platelet function analyzer system, PFA-100(R), over a period of 1 year. Patients and methods: A group of 98 patients (43 females, 55 males) with PAOD, treated with aspirin (n = 52), thienopyridine (n = 34) or combination therapy of both (n = 12) were followed over a period of 12 months after elective PTA of the lower extremities with regard to occurrence of restenosis or reocclusion at the site of angioplasty, to demonstrate inhibitory effects on platelets, induced by antiplatelet therapy. Results: PFA-100 proved suitable to identify 'non-responders' to antiplatelet therapy, in a 12-month follow-up period. In 'non-responders' to clopidogrel therapy, a higher incidence of restenosis or reocclusion after PTA of the lower limbs was detected compared with 'responders'. Conclusion: PFA-100, upon stimulation with ADP, might predict patients under clopidogrel therapy with elevated risk for the development of complications following PTA of the lower limbs. This could offer the chance to switch to an alternative therapy or adapt the dose.