NICE approves genomic test to prevent secondary strokes
We report on a new test that will help clinicians determine when clopidogrel may harm instead of help
The National Institute for Health and Care Excellence (NICE) has published guidance for the use of a genomic test to determine whether the antiplatelet drug clopidogrel should be used following a stroke. Testing can either be performed in a traditional laboratory, or by a rapid point of care test (POCT). The non-invasive POCT, which can be performed at the bedside where necessary, will identify those with a gene variant that puts them at higher risk of having another stroke if treated with the drug.
NICE is working with NHS England, who will initially deliver a national pilot to inform future implementation of the guidance.
What is clopidogrel?
Stroke affects around 100,000 people in the UK each year. It is the fourth most common cause of death and the leading cause of disability. There are two types of strokes: ischaemic, where blood supply is stopped because of a blood clot; and haemorrhagic, caused by a weakened, burst blood vessel. A related condition, transient ischaemic attack (TIA), is caused by a temporary interruption to the brain’s blood supply.
Clopidogrel is an antiplatelet medication that is often recommended to prevent the risk of future strokes. It slows the blood’s clotting action by making platelets less sticky, which prevents clots from forming. It is used to help prevent ischaemic strokes and TIA.
Around 32% of people in the UK, however, have a variant in the CYP2C19 gene that makes the drug far less effective. Current evidence also suggests that people with this gene variant who take clopidogrel are 46% more likely to have another stroke. Knowing whether an individual has this gene variant, then, can be instrumental in guiding their care and mitigating risk.
An issue of scale
There is great potential for genomic testing to limit the damage caused by stroke in the UK. University of Manchester NIHR doctoral research fellow and clinical genetics specialty registrar Dr John McDermott explains: “Over 100,000 patients a year are affected by stroke, so [the new test] will fundamentally change the landscape of pharmacogenomics in this country. There are some really exciting things to think about – how do we do that? How do we test that many people that quickly? Because we just don’t do that at the moment.”
- Learn more: Pharmacogenomics GeNotes
As part of its guidance, NICE has proposed a way forward to help limit the strain on services while testing capacity is increased over time. A phased rollout is suggested, with tests offered to those at higher risk of stroke recurrence, or point-of-care testing within the community “as an alternative if laboratory-based testing is not feasible at this scale, or while capacity for laboratory-based testing is increased”.
Exploring rapid testing
NICE recommends laboratory testing where possible, but is also supportive of a POCT that Dr McDermott and his team have been involved in developing that could help the NHS implement this new guidance more quickly.
“[Our group has] been involved in the development and validation of different rapid point-of-care tests,” Dr McDermott explains. “With a company called Genedrive, here in Manchester, we’ve developed a test where you take a cheek swab and put it into a machine and it will produce a result to help guide anti-platelet therapy within an hour. It’s a really exciting development that we’ve just finished validating and the results are extremely impressive.”
Such rapid testing has many advantages, including being able to offer alternative treatments to patients much sooner and easing pressures on the wider healthcare system.
“[It is estimated that patients who have adverse drug reactions] take up around 8,000 hospital beds at any one time and the costs to the NHS are measured in billions. So even small improvements in the safety and effectiveness of medicines could have a significant impact on the healthcare system as a whole. Medicines working well are good for patients, but also good for health systems since it means people get better quicker and can potentially be discharged quicker.”
- Read next: Three experts explore ‘our genomic future’
More information about this story can be found in our related articles from June 2023 and April 2024. Follow this blog for further updates as they become available.
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