Abstract 15389: High On-Treatment Platelet Reactivity in Clopidogrel-Treated Patients Undergoing Elective Carotid Stenting: Correlation with Previous Cerebrovascular Events
Background: High on-treatment platelet reactivity (HPR) is an established predictor of adverse cardiovascular outcome in patients with coronary artery disease treated with clopidogrel. No data are available on the prognostic value of HPR in patients with cerebrovascular disease. Our aim was to study the response to clopidogrel in patients undergoing carotid artery stenting (CAS).
Methods: Consecutive patients undergoing CAS were enrolled in a prospective study. Clopidogrel, in combination with aspirin, was started before the procedure and continued for at least one month. Platelet reactivity was assessed in 137 patients on the day of the procedure, in 122 after 24 hrs and in 91 after 30 days. Platelet reactivity was assessed by light transmission aggregometry (ADP 5 microM), VerifyNow P2Y12 assay, Multiplate and VASP-P assay. HPR was defined according to cut-off values established by the recent consensus on HPR.
Results: HPR, as detected by two or more tests, was found in 29.9% of clopidogrel-treated patients undergoing CAS. Patients with previous cerebrovascular events [Odds ratio (OR) 2.8; 95% Confidence Intervals (CIs) 1.16-6.94; p=0.030), stroke (OR 2.9; 95% CIs 1.04-8.37; p=0.049) or any ischemic cerebrovascular or cardiac events (2.57; 95% CIs 1.13-5.41;p=0.029) were more likely to show HPR. The association between previous cerebrovascular events and impaired platelet response to clopidogrel was confirmed after adjustment for demographic and clinical variables (multiple logistic regression with forward stepwise selection) (OR 3.5; 95% CIs 1.16-6.94; p=0.009).
Conclusions: Around one-third of clopidogrel-treated patients undergoing CAS present HPR. Among patients undergoing CAS HPR identifies a subgroup at higher cardiovascular risk. Follow-up of this ongoing study will allow to define whether HPR predicts subsequent cardiovascular events.
- © 2012 by American Heart Association, Inc.