Testing Could Help Prevent Further Strokes In People With Gene Variant

People who have had an ischaemic stroke or transient ischaemic attack (TIA) should have a genetic test to find out whether they can be treated with a drug which reduces the risk of further strokes, NICE has said.

New draft guidance from NICE has recommended clinicians offer laboratory-based genotype testing to people if treatment with the drug clopidogrel is being considered.

The genotype test would be used to find out who has these variants so they can be treated with an alternative drug.

There are around 100,000 strokes every year in the UK, of which around 43,000 are recurrent strokes. Each year, 46,000 people in the UK have a TIA for the first time – a warning that they are at risk of stroke.

At present no testing takes place to find out who is suitable for treatment with clopidogrel. An estimated 32% of people in the UK have at least one of the highlighted CYP2C19 gene variants. They are more commonly found 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 around a 46% 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 will be treated with another medicine, which will be more effective at preventing future blood clots.

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

Mark Chapman, interim director of medical technology and digital evaluation, at NICE, said:
“The recommendation is a step forward in ensuring people who have had a stroke receive personalised care thanks to a genetic test run after their DNA is sequenced using their blood or saliva.

“Treatment with clopidogrel is effective in preventing further strokes for the majority of people who don’t have the gene variant. But until now doctors have not known who cannot be treated with clopidogrel until after they’ve had a second stroke or TIA and that could be too late.

“If the CYP2C19 variants are found, other treatment options can be used. This test ensures we’re getting the best care to people quickly, while at the same time ensuring value for money for the taxpayer.”

A consultation has begun on the draft recommendations and consultees can have their say via nice.org.uk until Wednesday, 8 June 2023.