Abstract 2014: Additive Cilostazol to Dual Antiplatelet Therapy Achieves Greater Inhibition of Platelet Aggregation Compared With High Maintenance-Dose Clopidogrel in Patients With Acute Myocardial Infarction
Objectives The aim of study was to compare platelet inhibition by additive cilostazol to dual antiplatelet therapy (triple antiplatelet therapy) and high maintenance-dose (MD) clopidogrel 150mg/d in patients with acute myocardial infarction (AMI).
Methods AMI patients undergoing successful stenting (n =90) were randomly assigned to 1 of 3 MD regimens: Standard group, clopidogrel 75 mg/d; High MD group, clopidogrel 150 mg/d; Triple group, additive cilostazol 100 mg twice daily. Platelet functions were evaluated before discharge and 30 days after discharge. Percent inhibition (PI) and a rate of poor responder to clopidogrel were assessed, based on maximal and late platelet aggregation (Aggmax and Agglate).
Results Baseline platelet measures were similar in 3 groups. There was more potent and consistent PI by Triple group in all platelet measures. PI of 5 uM ADP-induced Aggmax was 3.5% in Standard group, 22.6% in High MD group, and 44.1% in Triple group (p < 0.001). In addition, PI of 5 uM ADP-induced Agglate was 12.3%, 31.5%, and 65.0% in each group, respectively (p < 0.001). Similar results were demonstrated when 20 uM ADP and 6 ug/ml collagen were used. In terms of poor response to clopidogrel (5 and 20 uM ADP-induced Aggmax > 50%), fewer patients in triple group (4.3% and 23.3%) met a criteria than those in standard group (23.3% and 73.3%) and high MD group (16.7% and 60.0%) at 30 days (p = 0.028 and < 0.001, respectively). All parameter between Triple and High MD groups were significantly different.
Conclusions Triple antiplatelet therapy achieves greater platelet inhibition and lesser rate of poor response to clopidogrel compared with high MD clopidogrel in AMI patients.