Background : Clopidogrel is a powerful arm to prevent major cardiovascular event in patients undergoing coronary intervention. The platelet responsiveness to clopidogrel is highly variable among individuals and there are many methods to measure the degree of platelet inhibition. The aim of our study was to determine; the degree of clopidogrel responsiveness determined by VerifyNow짰 in patients undergoing percutaneous coronary intervention, the role of clopidogrel resistance on outcome in the follow-up.
Method and Results : From July 2006 to Jan 2007, total 279 patients who underwent percutaneous coronary intervention at our institution were consecutively enrolled. After successful PCI, we measured platelet responsiveness of clopidogrel using VerifyNow P2Y12짰 before discharge and followed up during 6 months at outpatient department and in-hospital center. Absolute PRU values were divided into tertiles and the highst PRU group was defined as the clopidogrel resistance group. Total of 72 patients(25% ) had clopidogrel resistance. The male gender was identified as independent predictor of clopidogrel resistance. (OR 2.46, 95% CI 1.362-34.434, p=0.003) At 6 month follow-up, major adverse cardiovascular events (including death, TLR, TVR, CVA, repeated PCI to other vessel, etc.) was 30 case. (Group 1 = 13 cases, group 2 = 18 cases, p =0.025) Clopidogrel resistance was independent predictor of MACE. (OR 2.593, 95% CI 1.175-5.725, p=0.018)
Conclusion : The clopidogrel resistance was high prevalence in male patients. In the case of high baseline PRU, careful observation should be needed for prevention of major adverse cardiovascular events and we should consider the use additional antiplatelet agents.