personalized antiplatelet secondary stroke prevention

Conditions: Ischemic Stroke; TIA

Summary: this is a descriptive study designed to evaluate the safety and feasibility of a precision medicine approach to antiplatelet selection for secondary stroke prevention.

subjects meeting inclusion/exclusion criteria will be randomly assigned to: (1) the treatment group where antiplatelet medications will be selected using platelet function phenotype and/or key pharmacogene genotypes (2) the control group where participants will receive standard care for antiplatelet therapy (without knowledge of phenotype or genotype).

Eligibility criteria:
inclusion criteria: * provide signed and dated informed consent form. * willing to comply with all study procedures and be available for the duration of the study. * meet criteria for a mild or moderate ischemic stroke or high-risk tia * ability to randomize within 30 hours of stroke symptom onset/last seen normal time exclusion criteria: * evidence of new or prior non-traumatic intracerebral hemorrhage, subarachnoid hemorrhage, or subdural hemorrhage on initial head ct * evidence of a central nervous system tumor, abscess, intracranial aneurysm or vascular/structural malformation, or any neuro-inflammatory, neuro-infectious, or neurodegenerative disorder on neuroimaging or exam that could confound a participant's functional outcome * isolated or pure sensory symptoms (e.g., numbness), visual changes, or "dizziness"/vertigo without evidence of acute ischemic stroke on baseline head ct or mri. * qualifying ischemic event is believed to be iatrogenic or procedure related * required to take a specific antiplatelet medication for an indication other than ischemic stroke during the study period that would prevent the investigator from following the study algorithm * etiology of qualifying ischemic event is known to be cardioembolic * high likelihood that anticoagulation will be needed during the study period. * high likelihood that carotid endarterectomy or carotid stenting will occur during the period of the study. * pre-stroke modified rankin scale (mrs) score ≥ 3 * evidence of frailty * contraindication to aspirin, clopidogrel, aggrenox®, or ticagrelor * known allergy or hypersensitivity that would prevent the investigator from following the study algorithm * any history of moderate to severe drug-induced adverse events * renal insufficiency or history of kidney transplant * hepatic impairment, international normalized ratio (inr) \> 1.5, physical manifestations of liver disease, or history of liver transplant * class ii, iii, or iv new york heart association (nyha) functional heart failure * any history of bradycardia without pacemaker placement * active obstructive lung disease * any active hematologic disorder * active bleeding diathesis * any systemic hemorrhage or gi bleed in the 3 months prior to the qualifying stroke * active peptic ulcer disease * women who self-report that they are pregnant or breastfeeding * active alcohol or substance abuse or dependence * inability or failure to provide informed consent. * inability of the patient to adhere to study procedures and/or follow-up, in the opinion of the investigative team * inability to swallow oral medications * not willing or able to discontinue prohibited concomitant medications * ongoing participation in another non-observational clinical study * life expectancy \< 1 year, in the opinion of the investigative team