Effect of cilostazol addition or clopidogrel doubling on platelet function profiles in diabetic patients undergoing a percutaneous coronary intervention

BackgroundWe investigated the pharmacodynamic effect of cilostazol addition (100 mg twice, Triple) or clopidogrel doubling (150 mg daily, Double) on standard dual antiplatelet therapy in type 2 diabetes mellitus (T2DM) patients with clopidogrel resistance undergoing a percutaneous coronary intervention.Methods and resultsThis was a prospective, randomized, cross-over platelet function study. Percent inhibition less than 20% was used as the cutoff value of clopidogrel resistance. After percutaneous coronary intervention, a total of 50 T2DM patients with clopidogrel resistance were assigned to receive cilostazol 100 mg twice daily or clopidogrel 150 mg daily for 28 days; afterwards, they received cross-over treatment for another 28 days. Eight patients were excluded because of side effects and follow-up loss. The platelet function test using VerifyNow was performed at three time points: at baseline (T0), 28 days after randomization (T1), and 28 days after cross-over treatment (T2).A total of 42 T2DM patients completed the study protocol. The clopidogrel resistance improved significantly following cilostazol addition or clopidogrel doubling treatment compared with baseline (52.927.0 in Triple, 45.4 +/- 16.8% in Double, P<0.001 in both). This effect continued after cross-over treatment (58.1 +/- 26.1 and 41.0 +/- 20.0%, respectively, both P<0.05). A head-to-head comparison between two groups showed a lower P2Y12 reaction unit (PRU) and higher percentage of platelet inhibition in the Triple than those in the Double group (PRU, 138.7 +/- 88.2 vs. 198.8 +/- 19.5, P=0.049; %platelet inhibition, 58.1 +/- 26.1 vs. 40.97 +/- 20.0, P=0.048).ConclusionAdjunctive treatment with cilostazol in T2DM patients on standard dual antiplatelet therapy might be a more effective strategy for overcoming clopidogrel resistance than clopidogrel doubling treatment.