Abstract
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 μM 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.
Original language | English (US) |
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Pages (from-to) | 1392-1396 |
Number of pages | 5 |
Journal | Journal of the American College of Cardiology |
Volume | 45 |
Issue number | 9 |
DOIs | |
State | Published - May 3 2005 |
Externally published | Yes |
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine