Effect of cytochrome P450 2C19 polymorphism on target lesion outcome after drug-eluting stent implantation in japanese patients receiving clopidogrel.

Background:  Cytochrome P450 (CYP) 2C19 polymorphism is associated with reduced responsiveness to clopidogrel and poor clinical outcome after drug-eluting stent (DES) implantation, but its contribution to lesion outcome after DES implantation is unclear.
Methods and Results:  The study included 160 Japanese patients who received clopidogrel and underwent DES implantation with follow-up angiography. Patients were divided into 3 groups by CYP2C19 polymorphism: extensive metabolizers (EM), intermediate metabolizers (IM), and poor metabolizers (PM). The incidence of major adverse cardiac events (MACE) and target lesion revascularization (TLR) were compared among the 3 groups. Optical coherence tomography (OCT) was performed for 120 patients to evaluate the incidence of intra-stent thrombi. Of the 160 patients, the proportion of EM, IM, and PM was 37.5%, 48.1%, and 14.4%, respectively. The incidence of TLR and MACE was more frequent in IM and PM than EM (TLR: 18.2% and 26.1% vs. 3.3%, P=0.008, MACE: 22.1% and 30.4% vs. 5.0%, P=0.005). Among the 120 patients who underwent follow-up OCT, intra-stent thrombi were more frequently detected in IM and PM than in EM (45.6% and 63.2% vs. 20.5%, P=0.005). The incidence of TLR was significantly higher in patients with than in those without intra-stent thrombi (27.7% vs. 6.8%, P=0.003).
Conclusions:  CYP2C19 loss-of-function polymorphism might be associated with the incidence of MACE and TLR in association with intra-stent thrombi.