The Effective And Safety Of Maintenance Dose Of Clopidogrel For Patients With Acute Coronary Syndrome After Percutaneous Coronary Intervention

Objective:To evaluate the efficacy and safety of a150mg maintenance dose of clopidogrel in patients with an acute coronary syndrome (ACS) undergoing percutaneou coronary intervention(PCI).Methods:Between January2012and July2012, a total of242consecutive ACS patients undergoing PCI were enrolled, patients were randomized to double-dose clopidogrel (a300-mg loading dose on day1, followed by150mg daily for7days and75mg daily thereafter) or standard-dose clopidogrel (a300-mg loading dose and75mg daily thereafter). Record of major adverse cardiac event (MACE)(cardiac death, myocardial infarction and urgent target vessel revascularization),stent thrombosis and major and minor bleeding events in hospital,then followed the events after30days and6months.Results:a total of242consecutive ACS patients undergoing PCI were enrolled,125patients and117patients were enrolled in the standard and high maintenance dose group respectively.The mean age were68.95±10.33ys,147male and95female.①There was no statistically significant difference between groups with baseline characteristic (age,gender,smoking or drinking),history(hypertension, coronary heart disease,diabetes, stroke, Myocardial infarction, or CABG),clinical Biochemical indicators(kidney function, blood lipid levels, blood routine, white blood cells, fiber protease, left atrial and left ventricular end-diastolic diameter and left entricular ejection fraction),Hospital diagnosis and the proportion of patients taking other cardiovascular drugs.②There was no statistically significant difference between groups with angiography features (lesion counts, criminals vessels) and interventional treatment (stent length, diameter and pressure of expansion and stent type)(P>0.05). ③During the period of hospital:The standard-dose clopidogrel group has3cases occurred stent thrombosis (2.4%), a total of6MACE (4.8%), including3cases of myocardial infarction (2.4%),2cases of TVR (1.6%),1cases died (0.8%),respectively. In double-dose clopidogrel group,1case occurred stent thrombosis (0.9%), a total of2MACE (1.7%),1case of myocardial infarction (0.9%),1cases died (0.9%) respectively. Double-dose clopidogrel group has a tendency to reduce MACE and stent thrombosis events,there was no statistically significant difference between groups with MACE(4.8%VS1.7%,P=0.179)and stent thrombosis events (2.4%VS0.9%,P=0.346). In standard-dose clopidogrel group,5cases with minor bleedings (4%), major bleedings occurred in1case (intracerebral hemorrhage)(0.8%), a total of6bleeding events (4.8%). In double-dose clopidogrel group,10patients with minor bleedings (8.5%). Double-dose clopidogrel group has a tendency to increase minor bleedings events.There were no significant differences between groups regarding the risk of bleedings (major bleedings and minor events)(4.8%VS8.5%, P=0.241).④During30days of follow-up:The standard-dose clopidogrel group has1cases occurred stent thrombosis (0.8%),1cases of myocardial infarction (0.8%),1cases of TVR (0.8%),respectively. Double-dose clopidogrel group has a tendency to reduce MACE and stent thrombosis events, there was no statistically significant difference between groups with MACE(1.6%VS0%, P=0.169)and stent thrombosis events (0.8%%VS0.9%,P=0.332). In standard-dose clopidogrel group,2cases with minor bleedings (1.7%), double-dose clopidogrel group with1minor bleedings (0.8%). Double-dose clopidogrel group has a tendency to increase minor bleedings events,there were no significant differences between groups regarding the risk of bleedings (major bleedings and minor events)(0.8%VS1.7%, P=0.523).⑤During6months of follow-up:In standard-dose clopidogrel group,1cases with minor bleedings (0.8%), double-dose clopidogrel group with1minor bleedings (0.9%). There were no significant differences between groups regarding the risk of bleedings (major bleedings and minor events)(0.8%VS0.9%, P=0.963).Conclusion: 1. Double maintenance dose of clopidogrel (150mg/d x7d) has a tendency to reduce MACE and stent thrombosis events, but there was no statistically significant difference between groups.2. Double-dose clopidogrel group has a tendency to increase minor bleedings events,but there was no statistically significant difference between groups. Double maintenance dose of clopidogrel did not increase the incidence of major bleeding events.