Clopidogrel, an antiplatelet prodrug, is widely used for prevention of the recurrent cardiovascular events. CYP2C19 is one of the crucial enzymes for the activation of clopidogrel. Recent studies, mostly done in cardiovascular patients, showed association of the CYP2C19 genotypes with recurrent cardiovascular events. However, prospective data on the impact of the genetic variants in stroke patients are limited.
Five hundred and eighteen Japanese non-acute stroke patients treated with clopidogrel were registered at 14 institutions. Three CYP2C19 variants (CYP2C19*2, *3, *17) were genotyped and the patients were classified into three clopidogrel metabolizer groups inferred from the CYP2C19 genotypes: extensive (EM: *1/*1), intermediate (IM: *1/*2 or *1/*3), and poor (PM: *2/*2, *2/*3, or *3/*3). The CYP2C19*17 carriers were excluded from the analysis. The antiplatelet effects of clopidogrel were assessed by Adenosine diphosphate (ADP) -induced platelet aggregation and vasodilator-stimulated phosphoprotein (VASP) phosphorylation, expressed as VASP index. The endpoint was the composite incidence of stroke, transient ischemic attack, myocardial infarction, revascularization, other thromboembolic disease, or cardiovascular death during 2 years of follow-up.
- Clopidogrel (Plavix®)Drug
Other Names: Plavix
- Observation: Cohort
- Perspective: Prospective
- Sampling: Probability Sample
Patients were recruited at each institution between October 2009 and March 2012. The investigators enrolled males and females aged 20 years or older who had experienced cerebral infarction or transient ischemic attack (TIA) (except for cardiogenic embolism) in the prior 3 years but not in the last one month, who received long-term clopidogrel therapy (75 mg once a day) for the secondary prevention (for at least one month), and who were willing and able to give written informed consent.
|Type||Measure||Time Frame||Safety Issue|
|Primary||The primary outcome of the study was recurrent cardiovascular event (CVEs), including ischemic stroke, transient ischemic attack (TIA), acute myocardial infarction, urgent revascularization, other thromboembolic disease, and cardiovascular death.||Two Years||Yes|
|Secondary||Secondary outcome was major bleeding (intracranial haemorrhage, documented retroperitoneal bleed, and any red blood cell transfusion rates or proportion with bleeding associated with a ≧2g/dl hemoglobin drop).||two years||Yes|
Biospecimen Retention:Samples With DNA - Genomic DNA was extracted from peripheral blood leukocytes. The genotypes of the CYP2C19*2 (c.681G>A, rs4244285), *3 (c.636G>A, rs4986893), and *17 (c.-806C > T, rs12248560) variants were determined by the TaqMan genotype discrimination method (Applied Biosystems, Foster City, CA, USA) using commercially available primers and probes purchased from the Assay-on-Demand system.