Diabetes mellitus and carotid artery plaques exhibiting high-intensity signals on MR angiography are related to increased platelet reactivity after carotid artery stenting.

Abstract

Increased platelet reactivity after carotid artery stenting (CAS) may cause thromboembolic complications. This study aimed to investigate the incidence of increased platelet reactivity after CAS and to determine the factors related to it. Patients who underwent CAS were recruited prospectively. They received pre-procedural antiplatelet therapy comprising some combination of aspirin (100 mg/day), clopidogrel (75 mg/day), and/or cilostazol (200 mg/day) for a minimum of 7 days. ADP- and collagen-induced platelet aggregation were measured before and 4 days after CAS. Changes in platelet reactivity were reported as changes in the categorized platelet reactivity grade based on the effective dose 50%. Clinical characteristics of patients with and without increased platelet reactivity were compared. Among 38 consecutive patients who underwent CAS, 18 (47%) exhibited increased platelet reactivity. Diabetes mellitus (OR 15.0; 95% CI 2.1 to 106.5; p=0.007) and carotid artery plaques exhibiting high-intensity signals (HIS) on time-of-flight MR angiography (TOF-MRA) (OR 25.2; 95% CI 2.0 to 316.2; p=0.013) were independently associated with increased platelet reactivity in a multivariate analysis. Increased platelet reactivity occurred in nearly half of the studied patients subjected to CAS and was independently associated with diabetes mellitus and carotid artery plaques exhibiting HIS on TOF-MRA.