A second consultation on recommendations that clinicians should offer CYP2C19 genotype testing when considering treatment with clopidogrel after an ischaemic stroke or Transient Ischaemic Attack (a “mini stroke”) has begun today, Wednesday 3 April 2024. 

NICE currently recommends clopidogrel as a treatment option for people at risk of a secondary stroke. For some people with certain variations in a gene called CYP2C19 other treatments could work better. The genotype test would identify people who have the gene variants so they can be offered an alternative treatment. 

The draft guidance recommends testing only for people who have very recently had a stroke or TIA. This is because the risk of another event is higher at this time and therefore so is the potential benefit of testing. As the risk of a recurrent stroke or a “mini stroke” reduces over time, so does the benefit of testing.  

For this reason, those people already taking clopidogrel will not be offered retrospective testing.  

People who are currently taking clopidogrel should continue with the treatment until they and their NHS clinician consider it appropriate to stop. 

Laboratory-based CYP2C19 genotype testing was the committee’s preferred option followed by the Genedrive CYP2C19 ID Kit point-of-care test. If neither of the first two options are available, the Genomadix Cube point-of-care test can be used. 

The NICE committee suggested that a phased rollout could be used when introducing laboratory-based testing with testing initially offered to people with a higher risk of stroke recurrence who would benefit most from it, such as people who have had a non-minor stroke. The committee recognised that it will take time to build up the testing capacity as no testing is currently undertaken to find out if clopidogrel is a suitable treatment. 

Around 35,850 people in England, Wales and Northern Ireland have a non-minor stroke each year.  

An estimated 32% of people in the UK have at least one of the highlighted CYP2C19 gene variants. They are more common in people with an Asian family background but can be found in people of any ethnicity. Evidence has suggested that people with these variants have an increased risk of another stroke when taking clopidogrel compared to those without them. 

If the test discovers they have one of the CYP2C19 gene variants, the person can be treated with another medicine to prevent future strokes. 

Around 11 million items of clopidogrel are dispensed each year at a cost of around £16 million to the NHS. 

"Recommending a genetic test that can offer personalised care to thousands of people who have a stroke each year will be a step forward in ensuring people receive the best possible treatment. 

“We recognise that capacity within laboratories will need to increase before everyone who has had a new stroke or ”mini-stroke” can receive testing. While point of care testing is an alternative, our committee has identified that initially those people who could benefit most from laboratory-based testing are those who have had a non-minor stroke. 

“Anyone who is currently being treated with clopidogrel should continue with the treatment. They should only stop after discussing the options with their clinician.” 

"Stroke devastates lives and leaves people with life-long disability. We know that many stroke survivors spend the rest of their lives fearing another stroke, so it's great to see that more people could be given appropriate help to significantly cut their risk of recurrent stroke.

"Getting on the right medication and taking it as advised can really go far to prevent further strokes. If you have been prescribed clopidogrel, you need to keep taking it. If you're worried about your risk of another stroke, you should speak to your doctor."

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