Can flow cytometry detect successful ticlopidine treatment in patients with VVI pacemakers?

An increased platelet activation status is present in patients with VVI pac emakers. With platelet activation, there is modulation of platelet surface molecule expression. In the current study, the expression of platelet surfa ce markers in WI patients before and after ticlopidine treatment and contro l subjects was investigated by means of flow cytometry. The study group con sisted of 25 patients with WI pacemaker, and 15 control subjects. CD42b, CD 61, and CD62p expression were significantly increased in WI patients compar ed with control subjects (CD42b p < 0.001, CD61 p < 0.005 and CD62p p < 0.0 01). In addition, after ticlopidine treatment, platelets showed a significa nt fall in expression of all these markers in VVI patients (CD42b p < 0.001 , CD61 p < 0.005 and CD62p p < 0.001). Our data suggest an increase of the surface expression of all these markers on platelets and demonstrate the ef ficacy of ticlopidine in reducing them.