Abstract 16416: Long-term Clopidogrel Therapy Improves Endothelial Function in Stable Coronary Artery Disease
Background: Recent data has shown clopidogrel therapy may be beneficial in reducing cardiovascular adverse events in patients with established atherothrombotic disease. Several studies have suggested that the benefit of clopidogrel may be, in part, due to effects not exclusively related to platelet aggregation. The primary aim of this study was to evaluate the effect of long-term clopidogrel therapy on endothelial function in subjects with stable coronary artery disease (CAD).
Methods: Forty patients with stable CAD on long-term aspirin therapy were randomized to clopidogrel therapy (75mg/daily) or control. Platelet function and endothelial function were assessed at baseline, one week and three months following randomization. Platelet function testing involved whole blood impedance aggregation (ADP 5μmol/L and 20μmol/L) and the Verify-Now point-of-care device (Accumetrics, USA). Endothelial function (via reactive hyperemic index, RHI) was assessed using a peripheral arterial tonometry device (Endo-PAT2000, Itamar Medical, Israel).
Results: The mean age of the cohort was 63.8±1.5 (SE), 88% were male. 95% of patients were on statin therapy and 75% were on an ACE inhibitor. 45% of subjects had had a previous percutaneous coronary intervention, with 38% previous coronary artery bypass grafting. The baseline mean RHI for the cohort was 1.78±0.08. At one week RHI increased by 20±10% in the clopidogrel group; this effect was maintained at three months (21±9% increase from baseline; p<0.01). There was a significant decrease in ADP-induced platelet aggregation in patients on clopidogrel at both concentrations as well as a decrease in P2Y12 reaction units (p<0.01). There was no correlation between baseline RHI and platelet aggregation using either method or between change in endothelial function and change in ADP-induced platelet aggregation at either time points in the clopidogrel arm.
Conclusion: Clopidogrel improves endothelial function in patients with stable CAD. This effect is independent of its effect on platelet aggregation.
- © 2010 by American Heart Association, Inc.