Platelet activation in patients who underwent carotid versus coronary stent revascularization

Background. Platelet activation occurs in coronary and carotid artery stenting as a result of vessel wall damage. Whether differences exist in the degree of platelet activation among stent-treated coronary and carotid vessel is not known. Aim. To compare platelet activation in patients who underwent carotid versus coronary revascularization. Methods. 20 patients with carotid stenosis and 20 stable angina patients who underwent BMS implantation were studied. Platelet activation markers (PAC1, CD62 and Tissue Factor [TF] and the % of monocyte-platelet aggregates [MPA]) were assessed by whole blood flow cytometry in resting conditions and upon in vitro ADP stimulation 1 month (T1) after stenting procedure and 2 months after thienopyridine discontinuation (T2). Results. At T1, CD62 and PAC1 positive (+) platelets were comparable in carotid and coronary-treated patients. By contrast, TF+ platelets as well as TF+ MPA were 3 fold higher in coronary vs carotid-treated patients, both under resting conditions and upon ADP stimulation (p<0.001). At T2 the platelet activation profile was comparable to that observed at T1, with TF+ platelets and TF+ MPA being still significantly higher (2-3 fold) in coronary vs carotid-treated patients, both under resting conditions and upon ADP stimulation (p<0.01). Conclusions. Significant higher levels of TF+ platelets and TF+ MPA were observed in coronary patients who underwent revascularization with stent implantation compared to patients with carotid artery stenting, both 1 month after stenting and 2 months after thienopyridine discontinuation. This prothrombotic platelet phenotype may have implications for thrombotic complications in coronary patients.