Objectives The object of this study was to determine the effect of pre -treatm ent with clopidogrel in patients undergoing elective stent implantation. Backgro und The treatment of patients with adenosine diphosphate receptor blockers after percutaneous coronary intervention (PCI) with stent implantation has been shown to decrease the incidence of subacute stent thrombosis. Furthermore, non-ra-n domized studies on pre-treatment with clopidogrel among patients undergoing ste nt implantation have suggested a reduction in myocardial damage and clinical eve nts. The effect of pre-treatment with clopidogrel has been studied in only a fe w randomized trials. Methods In a randomized trial, three days of pre-treatment with clopidogrel was compared with standard post-procedural treatment in 203 p atients undergoing elective stent implantation. The primary end point was a rise in troponin I or creatine kinase-MB fraction (CKMB) serum levels at 6 to 8 and 16 to 24 h after PCI. Secondary end points were death, stroke, myocardial infar ction, coronary bypass grafting, repeated PCI, and subacute stent thrombosis at one and six months after PCI. Results No difference was found between non-pre- treated and pre-treated patients in the postprocedural elevation of troponin I (42<<43.3%>> vs. 48 <<51.1%>>, respectively, p=0.31) or CK-MB (6 <<6.3%>> vs. 7 <<7 .4%>>, respectively, p=0.78). Adjustment for possible confounding factors did no t change these findings. Patient follow-up at one and six months showed no sign ificant difference between the treatment groups in death, stroke, myocardial inf arction, coronary artery bypass grafting, repeated PCI, or subacute stent thromb osis. Conclusions In this randomized study, no beneficial effect of pre-treatme nt with clopidogrel on post-procedural elevation of troponin I and CK-MB or on clinical events after one and sixth months could be demonstrated. The study sug gests that among patients with stable coronary syndromes in whom coronary stent implantation is planned, pre-trea-tment may not be beneficial in reducing earl y myocardial damage. Objectives The object of this study was to determine the effect of pre -tm ent with clopidogrel in patients undergoing elective stent implantation. Backgro und The treatment of patients with adenosine diphosphate receptor blockers after percutaneous coronary intervention (PCI) with stent implantation has been shown to decrease the incidence of subacute stent thrombosis. Furthermore, non-ra-n domized studies on pre-treatment with clopidogrel among patients undergoing ste nt implantation have suggested a reduction in myocardial damage and clinical events. The effect of pre-treatment with clopidogrel has The studied end of a randomized trial. Three times in pre-treatment with clopidogrel was compared with standard post-procedural treatment in 203 p atients undergoing elective stent implantation. The primary end point was a rise in troponin I or creatine kinase-MB fraction (CKMB) serum levels at 6 to 8 and 16 to 24 h after PCI. Secondary end point s were death, stroke, myocardial infarction, coronary bypass grafting, repeated PCI, and subacute stent thrombosis at one and six months after PCI. Results No difference was found between non-pre- treated and pre-treated patients in the postprocedural elevation of troponin I (42 << 43.3% >> vs. 48 << 51.1% >>, respectively, p = 0.31) or CK-MB (6 << 6.3% >> vs. 7 << 7 .4% >>, respectively, p = 0.78). Adjustment for possible confounding factors did no t change these findings. Patient follow-up at one and six months showed no significific difference between the treatment groups in death, stroke, myocardial infarction, coronary artery bypass grafting , repeated PCI, or subacute stent thrombosis. Conclusions In this randomized study, no beneficial effect of pre-treatme nt with clopidogrel on post-procedural elevation of troponin I and CK-MB or on clinical events after one and sixth months could be demonstrated The study sug gests that among patients with stable coronary syndromes in coronary CORPnt implantation is planned, pre-treatment may not be beneficial in reducing earl y myocardial damage.