Lack of efficacy of clopidogrel pre-treatment in the prevention of myocardial damage after elective stent implantation

OBJECTIVES The object of this study was to determine the effect of pre-treatment with clopidogrel in patients undergoing elective stent implantation. BACKGROUND 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-randomized studies on pretreatment with clopidogrel among patients undergoing stent implantation have suggested a reduction in myocardial damage and clinical events. The effect of pre-treatment with clopidogrel has been studied in only a few randomized trials. METHODS In a randomized trial, three days of pre-treatment with clopidogrel was compared with standard post-procedural treatment in 203 patients undergoing elective stent implantation. The primary end point was a rise in troponin I or creatine kinase-MB fraction (CK-MB) serum levels at 6 to 8 and 16 to 24 h after PCI. Secondary end points 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 post-procedural 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 not change these findings. Patient follow-up at one and six months showed no significant 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-treatment 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 suggests that among patients with stable coronary syndromes in whom coronary stent implantation is planned, pre-treatment may not be beneficial in reducing early myocardial damage. (C) 2004 by the American College of Cardiology Foundation.