|
|
||||||||||
|
J Am Coll Cardiol, 2008; 51:1066-1072, doi:10.1016/j.jacc.2007.12.013 © 2008 by the American College of Cardiology Foundation |
Department of Medicine, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada.
Manuscript received August 3, 2007; revised manuscript received November 23, 2007, accepted December 2, 2007.
* Reprint requests and correspondence: Dr. Philippe L. LAllier, Department of Medicine, Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec, Canada, H1T 1C8. (Email: philippe.lallier{at}icm-mhi.org).
Objectives: The objective of this study was to compare the level of platelet inhibition achieved by 3 different clopidogrel loading regimens in patients undergoing elective angiography and percutaneous coronary intervention when appropriate.
Background: Optimal platelet inhibition is a key therapeutic goal for patients undergoing percutaneous coronary intervention. Although 600 mg has been described as the maximum absorbed dose when given as a single bolus, the effects of 2 boluses given 24 h apart have not been described.
Methods: Patients (n = 148) were randomly assigned to one of 3 regimens: Group A, clopidogrel 300 mg the day before (
15 h) + 75 mg the morning of the procedure; Group B, clopidogrel 600 mg the morning of the procedure (
2 h); and Group C, clopidogrel 600 mg the day before (
15 h) and 600 mg the morning of the procedure (
2 h). Blood samples were obtained at baseline and immediately before angiography. Peak and late platelet aggregation were measured in platelet rich plasma, with researchers blinded to treatment allocation.
Results: There was a consistent difference favoring Group C in all aggregation parameters. Percent inhibition in Groups A, B, and C was 31.4%, 29.0%, and 49.5%, respectively, for peak aggregation (5 µmol/l adenosine diphosphate; p < 0.0001) and 54.1%, 57.7%, and 81.1%, respectively, for late aggregation (p < 0.0001). Similar striking reductions were observed when 20 µmol/l adenosine diphosphate was used. All comparisons between Group C and the other 2 groups were statistically significant, and those between Groups A and B were not.
Conclusions: Clopidogrel 600-mg double bolus achieves greater platelet inhibition than conventional single loading doses.
| ||||||||
Related articles in JACC:
| HOME | SUBSCRIPTIONS | CURRENT ISSUE | PAST ISSUES | CARDIOSOURCE | SEARCH | HELP | FEEDBACK |