Background: Triple antiplatelet therapy may have a beneficial effect on prevention of thrombotic complication in patients undergoing coronary stenting. We investigated the prevalence of aspirin and clopidogrel resistance in patients treated with dual and triple antiplatelet regimen after percutaneous coronary intervention (PCI) with drug-eluting stents (DES).
Methods: A total of 400 consecutive patients underwent successful PCI with DES were randomly assigned to therapy with dual antiplatelet regimens (aspirin plus clopidogrel, Group I, n = 200) and triple antiplatelet regimens (aspirin plus clopidogrel plus cilostazol, Group II, n = 200) At two weeks after PCI, aspirin and clopidogrel resistance were assayed in 379 patients (Group I, n = 186; Group II, n = 193) by using the VerifyNow System.
Results: In Group I, 21 (11.3%) patients had aspirin resistance and 74 (40.0%) had clopidogrel resistance. In Group II, 19 (9.8%) were resistant to aspirin and 38 (19.7%) to clopidogrel. The aspirin reaction unit (ARU) was not significantly different between groups (448+/-67 vs. 439+/-64, P = 0.200), but the percent inhibition of clopidogrel was higher in Group II (41.4+/-24.3%,) comparing with that of Group I (26.5+/-18.7%, P < 0.001).
Conclusion: With triple antiplatelet therapy, the prevalence of clopidogrel resistance can be attenuated in patients undergoing PCI with DES.