Antiplatlet effects of a 600 mg loading dose of clopidogrel are not attenuated in patients receiving atorvastatin or simvastatin for at least 4 weeks prior to cononary artery stenting

Aims To test prospectively whether the antiplatelet effect of a 600 mg loading dose of clopidogrel is attenuated in patients receiving atorvastatin and simvastatin for at least 4 weeks prior to coronary artery stenting. Methods and results Blood samples were obtained at least 2 h after receiving 100 mg aspirin and 600 mg clopidogrel. and prior to coronary stenting from 90 patients without statin therapy and 90 patients with statin (atorvastatin and simvastatin) therapy for at least 4 weeks. Maximal. and residual platelet aggregation was evaluated with optical aggregometry in response to ADP (5 and 20 mumol/l). Surface expression of IIb/IIIa (CD61) and P-selectin (CD62) was assessed with whole blood flow-cytometry at base-line and following stimulation (5 and 20 mumol/l ADP). Inhibition of ADP-induced platelet aggregation was not impaired in the presence of concomitant statin therapy. Moreover, patients with and without statin therapy did not differ in respect to all ftow-cytometric parameters obtained. Conclusion The antiplatelet effect of a high, 600 mg loading dose of clopidogrel is not diminished in patients receiving atorvastatin and simvastatin for at least 4 weeks prior to coronary stenting. (C) 2004 Published by Elsevier Ltd on behalf of The European Society of Cardiology.