WSO - April 2023 - 416

1111898
WSO
International Journal of StrokeMicieli et al.
Research
Cost-effectiveness of testing for
CYP2C19 loss-of-function carriers
following transient ischemic attack/
minor stroke: A Canadian perspective
Andrew Micieli1 , Nishita Singh1, Beate Jahn2, Uwe Siebert2,3,4,
Bijoy K Menon1,5 and Andrew M Demchuk1
Abstract
Background: The CHANCE-2 study compared 3 weeks of aspirin-ticagrelor to aspirin-clopidogrel in CYP2C19 lossof-function
(LOF) allele carriers following a transient ischemic attack (TIA)/minor stroke and demonstrated a modestly
lower risk of stroke recurrence with aspirin-ticagrelor. This stroke protection was largely for minor stroke and came at an
increased risk of bleeding. The cost-effectiveness of implementing testing for LOF allele status to personalize antiplatelet
regimen for secondary stroke prevention after a TIA/minor stroke in the Canadian health care context is unknown.
Methods: Cost-effectiveness analysis using a decision-analytic Markov cohort model with a lifetime horizon was performed
to determine the costs and health benefits of testing for LOF allele status compared with no testing (current
standard of care). The population of interest was patients living in Canada who suffered a TIA/minor stroke. Outcomes of
interest were life-years gained (LYG), quality-adjusted life years (QALY) gained, costs (reported in 2022 Canadian dollars),
and the incremental cost-effectiveness ratio (ICER). We adopted the perspective of the Federal, Provincial, and Territorial
Ministries of Health and used a 1.5% annual discount rate. Sensitivity analyses were performed to assess uncertainty.
Results: Compared to standard of care, LOF allele testing leads to 0.14 LYG (undiscounted), 0.12 QALYs gained (undiscounted),
and additional lifetime costs of CAD$432 (discounted) per patient. The ICER of the LOF allele testing strategy
is CAD$4310 per QALY gained compared with standard of care. The probabilistic sensitivity analyses demonstrated
that LOF allele testing was cost-effective in more than 99.99% of simulations using a willingness-to-pay threshold of
CAD$50,000 per QALY.
Conclusion: Based on available evidence, testing for LOF allele followed by short duration 3 weeks of aspirin-ticagrelor
compared to standard-of-care aspirin-clopidogrel can lead to prolonged life and improved quality of life and can be considered
very cost-effective when compared with other well-accepted technologies in health and medicine.
Keywords
Aspirin, clopidogrel, cost-effectiveness, stroke, ticagrelor, transient ischemic attack
Received: 10 April 2022; accepted: 29 May 2022
1 Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
2 Institute of Public Health, Medical Decision Making and Health Technology Assessment, Department of Public Health, Health Services Research and
Health Technology Assessment, UMIT -University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria
3 Program on Cardiovascular Research, Institute for Technology Assessment and Department of Radiology, Massachusetts General Hospital, Harvard
Medical School, Boston, MA, USA
4 Center for Health Decision Science, Departments of Epidemiology and Health Policy & Management, Harvard T.H. Chan School of Public Health,
Boston, MA, USA
5 Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
Corresponding author:
Andrew Micieli, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Foothills Medical Centre, 1403 29
Street NW, Calgary, AB T2N 2T9, Canada.
Email: andrew.micieli1@ucalgary.ca Twitter: @MicieliA_MD
International Journal of Stroke, 18(4)
International Journal of Stroke
2023, Vol. 18(4) 416 -425
© 2022 World Stroke Organization
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DOI: 10.1177/17474930221111898
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