The relation of dosing to clopidogrel responsiveness and the incidence of high post-treatment platelet aggregation in patients undergoing coronary stenting.

Journal Article (Clinical Trial;Journal Article)

OBJECTIVES: We determined the effect of clopidogrel dosing on the incidence of nonresponsiveness (NR) and high post-treatment platelet aggregation (post-PA). BACKGROUND: We have reported NR after a 300-mg loading dose. Limited information is available on the comparative effect of a 600-mg loading dose on the incidence of NR and high post-PA. METHODS: Clopidogrel responsiveness and post-PA were measured in patients undergoing stenting (n = 190) randomly treated with either a 300-mg or a 600-mg clopidogrel load. Nonresponsiveness was defined as <10% absolute change in platelet aggregation, and high post-PA was defined as >75th percentile aggregation after 300 mg clopidogrel. RESULTS: Nonresponsiveness was lower after 600 mg compared to the 300-mg dose (8% vs. 28% and 8% vs. 32% with 5 and 20 microM ADP, respectively, p < 0.001). Among the patients with high post-PA after 300 mg clopidogrel, 62% to 65% had NR, whereas after the 600-mg dose, all of the patients with high post-PA had NR. CONCLUSIONS: A 600-mg clopidogrel loading dose reduces the incidence of NR and high post-PA as compared to a 300-mg dose. Higher dosing strategies and methods to confirm platelet inhibition should be further investigated in order to optimally use clopidogrel in patients undergoing stenting.

Full Text

Duke Authors

Cited Authors

  • Gurbel, PA; Bliden, KP; Hayes, KM; Yoho, JA; Herzog, WR; Tantry, US

Published Date

  • May 3, 2005

Published In

Volume / Issue

  • 45 / 9

Start / End Page

  • 1392 - 1396

PubMed ID

  • 15862408

International Standard Serial Number (ISSN)

  • 0735-1097

Digital Object Identifier (DOI)

  • 10.1016/j.jacc.2005.01.030


  • eng

Conference Location

  • United States