Clinical Impact of CYP2C19 Genotype on Clopidogrel-Based Antiplatelet Therapy After Percutaneous Coronary Intervention.

BACKGROUND: Although there is a growing body of evidence that CYP2C19 genotyping can be beneficial when considering treatment with clopidogrel after percutaneous coronary intervention (PCI), whether a genotype-guided strategy can be generally adopted in routine practice remains unclear among East Asians. OBJECTIVES: This study sought to investigate long-term outcomes of patients undergoing clopidogrel-based antiplatelet therapy after drug-eluting stent (DES) implantation according to CYP2C19 genotypes. METHODS: From the nationwide multicenter PTRG-DES (Platelet function and genoType-Related long-term proGnosis in DES-treated patients) consortium, patients who underwent CYP2C19 genotyping were selected and classified according to CYP2C19 loss-of-function allele: rapid metabolizers (RMs) or normal metabolizers (NMs) vs intermediate metabolizers (IMs) or poor metabolizers (PMs). The primary outcome was a composite of cardiac death, myocardial infarction, and stent thrombosis at 5 years after the index procedure. RESULTS: Of 8,163 patients with CYP2C19 genotyping, 56.7% presented with acute coronary syndrome. There were 3,098 (37.9%) in the RM or NM group, 3,906 (47.9%) in the IM group, and 1,159 (14.2%) in the PM group. IMs or PMs were associated with an increased risk of 5-year primary outcome compared with RMs or NMs (HRadj: 1.42; 95% CI: 1.01-1.98; P = 0.041), and the effect was more pronounced in the first year (HRadj: 1.67; 95% CI: 1.10-2.55; P = 0.016). The prognostic implication of being an IM and PM was significant in acute coronary syndrome patients (HRadj: 1.88; 95% CI: 1.20-2.93; P = 0.005) but not in those with stable angina (HRadj: 0.92; 95% CI: 0.54-1.55; P = 0.751) (interaction P = 0.028). CONCLUSIONS: Among East Asians with clopidogrel-based antiplatelet therapy after DES implantation, CYP2C19 genotyping could stratify patients who were likely to have an increased risk of atherothrombotic events. (Platelet Function and genoType-Related Long-term progGosis in DES-treated Patients: A Consortium From Multi-centered Registries [PTRG-DES]; NCT04734028).