The objective of the investigation is to test the hypothesis that the administration of abciximab bolus only plus high loading dose of clopidogrel at 600 mg will provide a non inferior level of inhibition of platelet aggregation 4 hours after administration as compared to abciximab bolus followed by standard infusion in combination with clopidogrel loading dose of 300 mg in patients with normal response to clopidogrel (as evaluated after 14-30 days).