[Relationship between ATP-binding cassette subfamily B member 1 and cytochrome P450 2C19 polymorphisms and the effect of clopidogrel post percutaneous coronary intervention in patients with acute coronary syndrome].

OBJECTIVE: To observe the relationship between ATP-binding cassette subfamily B member 1 (ABCB1) and cytochrome P450 (CYP)2C19 polymorphisms and the effect of clopidogrel post percutaneous coronary intervention in patients with coronary artery disease.

METHODS: A total of 300 consecutive patients with acute coronary syndrome undergoing selected percutaneous coronary intervention in General Hospital of the People's Liberation Army from October 2010 to August 2012 and treated with clopidogrel were enrolled and retrospectively analyzed. Antiplatelet responsiveness of clopidogrel was estimated by thrombelastograph. The patients were divided into 3 groups: remarkable efficacy group (adenosine diphosphate pathway inhibition rate >80%, 105 cases), effective group (adenosine diphosphate pathway inhibition rate of 50%-80%, 100 cases), and poor responsiveness group (adenosine diphosphate pathway inhibition rate <50%, 95 cases). CYP2C19 and ABCB1 polymorphisms were detected by PCR combined with restrictive fragment length polymorphism (PCR-RELP) method in all patients. A total of 200 patients were performed by high performance liquid chromatography with electrospray tandem mass spectrum methods (HTLC-MS/MS), which was applied for determining the plasma concentration level of clopidogrel metabolites between remarkable efficacy group and poor responsiveness group. Major adverse cardiovascular events and bleeding events were observed through follow-up.

RESULTS: (1) There were significantly differences in gender, smoking and alanine transaminase level among 3 groups(P<0.01 or 0.05). (2)There was no significant difference in the ratio of TT, CC and CT genotype of ABCB1 gene among 3 groups(P>0.05). There was significant difference in the ratio of poor, middle and strong metabolizer genotype of CYP2C19 gene (P<0.05). (3)Recurrent angina rates were 8.6%(9/105), 6.0%(6/100) and 18.9%(18/95) (P<0.05), and bleeding events rates were 1.0% (1/105), 1.0%(1/100) and 8.4%(8/95)respectively (P<0.01) in remarkable efficacy group, effective group and poor responsiveness group during the 1 year follow up. There were no significant difference in rates of myocardial infarction, heart failure, ischemic stroke and death among 3 groups (all P>0.05) during follow up. Rates of major adverse cardiovascular events and bleeding events were similar in patients with TT, CC and CT genotype of ABCB1 (14.6%(13/89), 12.8(19/148)and 11.6%(5/43), P>0.05). Rates of major adverse cardiovascular events and bleeding events were 9.5%(2/21), 17.8(27/152) and 7.5%(8/107) in poor, middle and strong metabolizer genotype of CYP2C19 gene patients (P<0.05). (4) Plasma concentration of clopidogrel was significantly lower and relative concentration of acid metabolites was significantly higher in poor responsiveness group than in remarkable efficacy group(P<0.01 or 0.05). There was no significantly different in plasma relative concentration of 2-oxo-clopidogrel between remarkable efficacy group and poor responsiveness group.

CONCLUSION: ABCB1 gene polymorphism is not but CYP2C19 gene polymorphisms is related with antiplatelet responsiveness of clopidogrel and clinical cardiovascular disease events in patients with acute coronary syndrome undergoing selected percutaneous coronary intervention.