Abstract 4269: Randomized Comparison of Additive Cilostazol and High Maintenance-Dose Clopidogrel in Patients with Poor Response to Clopidogrel
Background - The aim of the study was to compare platelet inhibition by additive cilostazol to dual antiplatelet therapy (triple antiplatelet therapy) and high maintenance-dose (MD) clopidogrel 150mg/d on in patients with poor response to clopidogrel (CR).
Methods and Results - Beginning with 300 mg loading clopidogrel at least 12 h before the procedure, 60 patients undergoing stenting with CR were included. CR was defined with 5 uM ADP-induced maximal platelet aggregation (Aggmax) > 50%. They were randomly assigned to triple therapy (triple group) or high MD clopidogrel (high MD group) for 30 days. Platelet functions were evaluated before the procedure and 30 days after stenting with aggregometry and VerifyNow P2Y12 assay. Baseline platelet measures were similar in 2 groups. Fewer patients in triple group met a criteria of CR than those in high MD group at 30 days (3.3% vs. 26.7%, P = 0.012). Percent inhibitions of 5 and 20 uM ADP-induced Aggmax were greater in triple group (53.0% and 38.8%) than high MD group (28.0% and 20.7%) at 30 days (P < 0.001 and < 0.001, respectively). Percent inhibitions of 5 and 20 uM ADP-induced late platelet aggregation (Agglate) of triple group (72.2% and 64.8%) were also higher than those of high MD group (45.3% and 33.1%) at 30 days (P < 0.001 and < 0.001, respectively). Triple group demonstrated a greater antiplatelet effect with higher percent change of PRU than high MD group at 30days (41.1% vs. 23.3%, P = 0.016).
Conclusion - In patients with CR, additive cilostazol reduces a prevalence of CR and achieves more intensified platelet inhibition than high MD clopidogrel.