Current Canadian stroke guidelines recommend the use of clopidogrel in combination with aspirin for stroke prevention after a minor ischemic stroke and transient ischemic attack (TIA). Clopidogrel is an oral P2Y12 inhibitor and pro-drug requiring metabolic activation by CYP2C19, a cytochrome P450 enzyme [2]. One-third of the Albertan population are unable to fully activate clopidogrel because they carry loss-of-function alleles (e.g., *2, *3) in their CYP2C19 gene, increasing their risk for subsequent major cardiac or cerebrovascular events (MACCE). Based on the current evidence, the U.S. FDA recommends that physicians “consider use of another platelet P2Y12 inhibitor” (e.g., ticagrelor) for individuals that carry one or more CYP2C19 loss-of-function alleles (i.e., intermediate or poor metabolizers). Moreover, the National Institute for Health and Care Excellence (NICE) in England recommends use of point-of-care CYP2C19 testing in people who have had an ischaemic stroke or TIA, if treatment with clopidogrel is being considered. Unfortunately, an effective strategy for implementing this testing into routine care in Alberta has not been established.


To develop and evaluate a point-of-care CYP2C19 testing implementation strategy that will inform the design of an externally funded, province-wide, hybrid type 3 effectiveness-implementation trial.    


Principal Investigators

Dr. Michael Hill, MD, Professor in the Departments of Clinical Neurosciences, Community Health Sciences, Medicine and Radiology at the University of Calgary

Dr. Chad Bousman, MPH, PhD, Associate Professor, Department of Medical Genetics, University of Calgary 


Dr. Jennifer Terpstra, MPH, PhD, Senior Consultant for Vascular Risk Reduction with the Cardiovascular Health and Stroke SCN and an Adjunct Assistant Professor in the Department of Community Health Sciences, at the University of Calgary.

Dr. Mark Boulos, MD,  Associate Professor, Medicine (Neurology), University of Toronto.


Meagan Shields, MSc, Department of Medical Genetics, University of Calgary 


University of Calgary

Libin Cardiovascular Institute

Alberta Precision Laboratories

Funding Partner


Michael and Terry Wilson Cardiovascular Research Innovation Fund