Comparison of Low vs Moderate Dose of Atorvastatin in Clopidogrel Resistance After Coronary Stenting in Korean Patients With Acute Coronary Syndrome

Background: The effect of atorvastatin 10 mg vs 40 mg in clopidogrel resistance and clinical events after coronary stenting was compared in patients with acute coronary syndrome (ACS). Methods and Results: Platelet aggregation was measured before clopidogrel administration and 4h, 24h, 5 days, and 8 months later in 130 ACS patients. Stented patients were randomly assigned to atorvastatin either 10 mg (n=65) or 40 mg (n=65), and received an oral loading dose of 300 mg of clopidogrel followed by 75 mg/day for 8 months. Measurement of platelet aggregation was done by the turbimetric method. The mean % changes in inhibition of platelet aggregation were 35.5 +/- 8.3, 50.9 +/- 10.1, 38.3 +/- 8.3, 40.0 +/- 6.8 in the Atorvastatin 10 mg Group and 31.0 +/- 7.6, 43.7 +/- 9.8, 45.0 +/- 10.3, 43.5 +/- 7.8 (4h, 24h, 5 days, and 8 months, respectively, after 300 mg of clopidogrel pretreatment) in the Atorvastatin 40 mg Group with no significant differences between the 2 groups. Cardiovascular events showed no significant differences during the follow-up. Conclusions: Atorvastatin 10 mg or 40 mg co-administered with clopidogrel for 8 months did not affect the antiplatelet potency of clopidogrel and showed no significant differences in the clinical events in ACS patients. (Circ J 2009; 73: 1111-1118)