NEW YORK (Reuters Health) – Compared to the standard 75-mg/d maintenance dose of clopidogrel, 150 mg/d produces greater platelet inhibition, higher flow-mediated vasodilation, and reduced inflammation – all of which may translate into clinical benefit. That’s according to study results presented in the February 15 issue of the Journal of the American College of Cardiology.

“Our study was not powered or intended to evaluate incidence of clinical events,” Dr. Giuseppe Patti, at Campus Bio-Medico University in Rome, Italy, and colleagues explain. Their aim was to explore the effects of 75 mg/d versus 150 mg/d clopidogrel maintenance on platelet function inhibition as well as other biological activities.

The study involved 50 patients who had undergone percutaneous coronary intervention and had been on 75 mg/d clopidogrel for a month. They were then assigned to continue on that dosage or to switch to 150 mg/d for 30 days. At the end of that period, the participants crossed over to the other dosage.

Platelet reactivity (measured by the VerifyNow assay) was significantly lower after the 150 mg/d period (141 units) than the 75 mg/d period (198 units), according to the report.

Furthermore, flow-mediated vasodilation in the brachial artery was improved more with the high dose compared to the standard dose of clopidogrel (16.9% vs 7.9%), and high-sensitivity C-reactive protein levels were lower (3.6 mg/L vs 7.0 mg/L), Dr. Patti and colleagues found.

They conclude that their study “indicates that a high clopidogrel maintenance dose, in addition to a stronger antiplatelet effect, is associated with significant ‘pleiotropic’ effects, which may potentially translate into a significant clinical benefit for patients undergoing PCI.”

Reference:

High Versus Standard Clopidogrel Maintenance Dose After Percutaneous Coronary Intervention and Effects on Platelet Inhibition, Endothelial Function, and Inflammation: Results of the ARMYDA-150 mg (Antiplatelet Therapy for Reduction of Myocardial Damage During Angioplasty) Randomized Study

J Am Coll Cardiol 2011;57:771-778.