[Relevance of CYP2C19 2 regarding platelet reactivity in patients with acute coronary syndrome treated with clopidogrel].

BACKGROUND AND OBJECTIVE

Previous studies have shown that the metabolism of P2Y12 receptor blockers is influenced not only by CYP2C19 2 but also by PON1-Q192R alelles. We aimed to evaluate the impact of CYP2C19 2 and PON1-Q192R polymorphisms carriage in platelet reactivity and clinical outcome in patients with ischemic heart disease undergoing cardiac catheterization.

PATIENTS AND METHOD

We recruited prospectively patients with acute coronary syndrome undergoing cardiac catheterization (n=247). We evaluated the genotype (CYP2C19 2, CYP2C19 17, PON1-Q192R) with TaqMan(®) assay and platelet aggregometry in all patients. We assessed both in and out-of-hospital events (unstable angina, periprocedural and spontaneous myocardial infarction, myocardial infarction, all-cause death, stent thrombosis and stroke) during follow-up.

RESULTS

Carriers of CYP2C19 2 alleles showed a significant higher residual platelet reactivity (PRU, mean [SD], 252 [76] vs. 287 [74], P=.002). Carriers of PON1-Q192R CT(RQ) and TT(QQ) alleles and CYP2C19 17 did not present a different response to clopidogrel. In a multivariable setting for the prediction of platelet reactivity, the contribution of CYP2C19 2 was modest (Wald=7.5; odds ratio [OR] for ≥ 1 alelle 2=2,786, 95% confidence interval [95% CI] 1,337-5,808). Independent predictors were baseline hemoglobin levels (g/dL, OR .666, 95% CI .555-.801) and the use of statins (OR .376, 95% CI .162-.873). Body mass index was a risk factor (OR 1,074, CI 95% 1,005-1,148). Studied polymorphisms did not predict an adverse outcome.

CONCLUSIONS

CYP2C19 2 polymorphism influenced moderately platelet reactivity but did not show an impact on clinical outcome in patients with acute coronary syndrome. Neither CYP2C19 17 nor PON1-Q192R polymorphisms showed an impact upon platelet reactivity or outcome.