I have gone through your history and details. The anticoagulation which is required after valve replacement is in the form of Acitrom or Warfarin. Persantin is added only when there is a thrombosis or embolisation. Now from your description, it is not clear the present status of your valve whether thrombus is still there or not. If your valve is functioning normally and there are no clots and thrombosis then discontinuing Persantin will not harm. Acitrom should be sufficient for anticoagulation. Still you should consult your neurologist and if he insists so, then you can discontinue the Persantin. You should be in regular contact with your cardiologist.