Overcoming Clopidogrel Resistance in Carotid Artery Stenting: Experience with Ticagrelor and Ticlopidine

Objectives: The goal of this study is to establish the incidence of high on-treatment platelet reactivity (HTPR) to aspirin and clopidogrel in patients undergoing carotid stenting and to evaluate the efficacy of ticagrelor and ticlopidine in patients with HTPR to clopidogrel. Methods: In a single institutional setting spanning eight years, every consecutive patient who underwent carotid artery stenting was incorporated into a study. Subsequently, a retrospective analysis of their platelet function was executed. Prevalence of high on-treatment reactivity to aspirin, clopidogrel, ticlopidine and ticagrelor was assessed. Platelet function testing was conducted by light transmission aggregometry and Multiplate^®. Results: A total of 216 patients were tested for antiplatelet therapy efficacy. The high on-treatment reactivity to clopidogrel was observed in 68 patients (31.4%). No patients with high on-treatment reactivity to ticagrelor or ticlopidine were observed. There was a significant reduction in platelet reactivity with ticagrelor (p < 0.000) and ticlopidine (p < 0.000) in patients with HTPR to clopidogrel. Conclusions: High on-treatment platelet reactivity to clopidogrel is common in patients undergoing carotid artery stenting. Ticagrelor is a viable alternative to overcome HTPR to clopidogrel. These findings suggest that platelet function testing can identify patients who may benefit from tailored antiplatelet therapy in reducing thromboembolic complications after carotid stenting.