A finger-prick blood test to diagnose the deadliest form of stroke might be twice as effective at spotting it than using a patient’s symptoms alone.
The test, which works similarly to a lateral flow test used to detect Covid, is being piloted by ambulance crews in Cambridgeshire.
The blood tests have been designed to detect if someone has suffered a large vessel occlusion (LVO), where a blood clot blocks a major artery in the brain.
This type of blood clot is responsible for about a third of strokes but causes about 95 per cent of disabilities and deaths.
A stroke is a very serious condition where the blood supply to part of your brain is cut off, and every minute a stroke is left untreated some 1.9 million brain cells die, increasing the risk of serious long-term disability and death, according to the Stroke Association.
However, speedy treatment for a stroke can dramatically increase a patient’s chances of recovery. This includes a thrombectomy procedure to remove the blood clot within a few hours of any symptoms appearing.
However, only 24 hospitals in the UK can provide thrombectomy treatment, and LVO is tricky to diagnose without a brain scan because it has similar symptoms to other conditions.
Due to a combination of NHS pressures and workforce shortages, these timeframes are often missed and only 3.9 per cent of eligible stroke patients had a thrombectomy in 2023/24 – against NHS England’s target of 10 per cent by 2027/28.
In addition, only 46 per cent were admitted to a stroke unit within four hours of arriving at a hospital, which further reduces the treatment window and the patient’s chances of recovery, the Stroke Association added.
As a result, unless a patient is lucky enough to live near a specialist centre, in most cases they will be taken to a general hospital. From there, it can take an average of three hours to be moved to a thrombectomy centre. However, these new finger-prick blood tests help diagnose LVOs faster and get patients the treatment they need.
The test, developed by the Cambridge-based firm UpFront Diagnostics, consists of two lateral flow cartridges and can detect two molecules in the blood.
One is a protein called D-dimer, which is associated with blood clots, and the other, called GFAP, is associated with bleeding in the brain. The absence of GFAP helps to rule out a haemorrhagic stroke where a blood vessel ruptures and bleeds, The Guardian reported.
These tests can detect LVOs with about 90 per cent accuracy within 15 minutes – which is more than double the accuracy of just checking symptoms, Gonzalo Ladreda, UpFront’s chief executive officer, told the newspaper.
Dr Louise Flanagan, the head of research for the Stroke Association, which helps fund the early development of the LVOne test, told The Independent: “When the NHS is under huge pressure and its workforce is in crisis, a simple finger prick test to help diagnose stroke could be revolutionary.
“The LVOne test could potentially diagnose stroke faster and much more affordably than the only current alternative, which is a brain scan. It could also help to identify the type of stroke a person is having, which is vital to ensure the right treatment is given.
“LVOne could help make it easier to decide whether someone is having a stroke that could be treated with a thrombectomy, saving the NHS time and money and, importantly, helping more people live well after stroke.”
The Stroke Association is calling for improvements in stroke care as part of the 10-year health plan – to help meet the government’s own target to reduce stroke disability and death by 25 per cent by 2035.
A Department of Health and Social Care spokesperson said: “This government is taking action to tackle the biggest killers like heart disease and strokes.
“We have introduced health checks in workplaces and blood pressure checks on high streets to help catch illness earlier, and we are acting to prevent strokes in the first place by tackling smoking and obesity.
“We are committed to improving stroke prevention, treatment, and recovery through our 10-year health plan, which will emphasise prevention and make better use of innovative technology like prehospital video triage as we shift the NHS from analogue to digital.”
There are 1.3 million stroke survivors in the UK, and 100,000 people have strokes every year. But 90 per cent of these are preventable, the charity said. Lifestyle factors such as obesity, smoking, alcohol intake and exercise levels can have a significant effect on a person’s stroke risk.
