Objective: To study platelet reactivity at different times while on dual antiplatelet therapy
(DAPT) with aspirin (ASA) and clopidogrel in patients treated with bioactive stents (TITAN2
everolimus-coated stents (XIENCE V®) and one month after clopidogrel cessation.
Background: Coronary intervention damages the endothelium and causes platelet response leading to
thrombotic occlusion, which is prevented with DAPT.
Methods: We studied 20 patients with bioactive stent and stable ischemia (BAS-SI group); 31 patients
with bioactive stent and acute coronary syndrome (BAS-ACS group) and 31 patients with stable
ischemia and everolimus-coated stent (EVE group). DAPT was administered (ASA 100 mg/day and
clopidogrel 75 mg/day) for one year in BAS-ACS and EVE groups and for 1 month in BAS-SI group.
Platelet aggregation induced by different agonists and platelet recruitment was analyzed at different
times of DAPT and 1 month after clopidogrel cessation.
Results: After one month of DAPT, platelet aggregation showed no difference between groups; at 12
months of DAPT, the response to collagen and ADP increased in EVE group. Platelet recruitment at 1
month was higher in the BAS-ACS than the other groups; after 12 months, recruitment increased in the
EVE group with respect to BAS-ACS. Platelet aggregation and recruitment in diabetics were significantly
higher in all situations than in non-diabetic patients. Clopidogrel withdrawal increased ADPinduced
aggregation and collagen-induced aggregation and recruitment.
Conclusion: Platelet reactivity in patients with DAPT varies with time, depending on the subset of patients,
the type of the stent implanted and the time after implantation.