Genotype Guided Antiplatelet Therapy In Ischemic Stroke
Singapore350 participantsStarted 2023-04-24
Plain-language summary
A fifth of ischemic stroke or transient ischemic attack (TIA) patients will have recurrent events within the first 3 months \[Refs 1-3\] despite aggressive medical therapy with antiplatelets and risk factor control.
Clopidogrel is one of the mainstays of antiplatelet secondary prevention therapy in patients with ischemic stroke. CYP2C19 loss of function (LOF) mutations impair the effectiveness of clopidogrel \[Ref 4\]. The prevalence of LOF mutations is approximately 60% in the local population \[Ref 5\], rendering the effectiveness of empiric clopidogrel treatment doubtful. For patients who have LOF mutations, other treatment options for secondary prevention of ischemic stroke need to be tested. This study aims to determine the feasibility and clinical impact of genetic testing guided antiplatelet therapy in ischemic stroke patients on the prevention of major adverse cardiovascular or cerebrovascular events.
Clopidogrel naive ischemic stroke or TIA patients aged 21 years and above will be randomised to genetic testing guided antiplatelet therapy or standard medical therapy within 7 days of their index event. Patients allocated to testing group will have blood sample drawn for diagnosis of CYP2C19 LOF mutations. Patients who test positive for an LOF mutation (intermediate and poor metabolisers) will be offered alternative antiplatelet therapy in the form of aspirn (for those who need monotherapy) or aspirin plus ticagrelor or dipyridamole (for those who need dual antiplatelet therapy) to be decided by the managing physician. Patients who test negative for LOF mutation will continue on clopidogrel. Platelet reactivity index (enables the identification of patients with an inadequate response to antiplatelet agents) will be measured at baseline.
Who can participate
Age range
21 Years – 100 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Patients diagnosed with acute ischemic stroke or transient ischemic attack.
* Age 21 years to 100 years.
* Can be randomised within 7 days of onset of index event \[Refer to footnote 1\].
* Clopidogrel naive immediately prior to index event \[Refer to footnote 2\].
Footnote 1: Date of index event to be taken as Day 1. This means that randomisation must be done by Day 7. For unknown onset or wake-up stroke where the last seen well and symptoms discovery are on different days, Day 1 is taken to be the date of symptoms discovery. Footnote 2: Patients who were on short-term antiplatelets which included clopidogrel but are no longer on clopidogrel prior to stroke would fulfil for this inclusion criteria. In this context, short-term antiplatelets are defined as 21 days for minor stroke TIA and 3 months for large vessel disease.
Exclusion Criteria:
* Known diagnosis of dementia \[Refer to footnote 3\].
* Known diagnosis of a life limiting illness with life expectancy of less than 1 year.
* Known cardioembolism or prothrombotic state necessitating the use of anticoagulation, or having a contraindication to clopidogrel.
Footnote 3: "Known diagnosis of dementia" will be defined as clinical diagnosis of dementia prior to the index stroke event as indicated in the patient's medical records.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Major adverse cardiovascular or cerebrovascular events (MACCE) over 12 months following the index stroke