Pharmacogenomics guided antiplatelet selection strategy prior to intracranial or carotid stenting.

Pharmacogenomics guided antiplatelet selection strategy prior to intracranial or carotid stenting. To determine whether pharmacogenomics testing allows accurate prediction of antiplatelet response prior to neurointerventional procedures. The study will involve one additional blood test to determine the pharmacogenomic profile for clopidogrel metabolism. Based on this patients who are responders will be started on the clopidogrel 75mg daily and those who are not will be started on a second line medication at standard doses ticagrelor 90mg twice daily or prasugrel 10mg daily. These medications are oral and given for a period as clinically indicated by the type and radiological appearances and clinical condition of the patient. This would usually be for a period of 6-12 weeks depending on the stent. Longer term dual antiplatelet therapy may be continued for select cases if there is an ongoing thromboembolic risk due to stent or patient factors. Compliance will be monitored on routine clinical review. Platelet response will be measured with the multiplate assay based on ADP values prior to any procedure.