Illustration of a person holding their head in their hand with the brain highlighted in red and showing signs of ischemic stroke
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Brigham and Women’s Hospital researchers say they have developed a test that combines a new blood-based test with a clinical score that can significantly shorten the time to stroke detection. The new test, described today in the journal Stroke: Vascular and Interventional Neurology, will help doctors diagnose a type of stroke called large vessel occlusion (LVO), an often life-threatening blockage of a major artery to the brain.

“We have developed a game-changing, accessible tool that could help ensure that more people suffering from stroke are in the right place at the right time to receive critical, life-restoring care,” said senior author Joshua Bernstock, MD, PhD, a clinical fellow in the department of neurosurgery at Brigham and Women’s Hospital.

While most strokes are ischemic, characterized by an obstruction of blood to the brain, LVO strokes are an aggressive form of the condition that blocks a much larger volume of blood to the brain and can result in the death of vital brain cells within minutes. Properly identifying LVOs, which are major medical emergencies, can provide swift treatment with a surgical procedure called a mechanical thrombectomy that relieves the arterial blockage.

“Mechanical thrombectomy has allowed people that otherwise would have died or become significantly disabled be completely restored, as if their stroke never happened,” said Bernstock. “The earlier this intervention is enacted, the better the patient’s outcome is going to be. This exciting new technology has the potential to allow more people globally to get this treatment faster.”

The key to the new diagnostic technique for stroke detection was the identification of two proteins found in capillary blood. One, called glial fibrillary acidic protein (GFAP), is also associated with brain bleeds and traumatic brain injury (TBI). The second is D-dimer, which is a small protein fragment present in the blood after a blood clot has degraded. This protein is already used in diagnostic testing for conditions such as venous thromboembolism.

The investigators discovered testing for these protein biomarkers and combining results with field assessment stroke triage for emergency destination (FAST-ED) scores—a method of scoring stroke severity prior to a patient arriving at the hospital—could identify LVO ischemic strokes while ruling out other conditions such as bleeding in the brain. LVOs and brain bleeds often exhibit similar symptoms making them hard to distinguish, while the treatments of each very different from one another.

The prospective study of combining the two diagnostics techniques, used the data of 323 patients that were coded for stroke in Florida between May 2021 and August 2022. When applying this new diagnostic approach for patients within six hours of less than six hours after first onset of symptoms, the method exhibited 93% specificity and 81% sensitivity in identifying LVOs. Further, the test ruled out all patients with brain bleeds indicating that is could eventually be deployed for field testing of intracerebral hemorrhage.

One potential benefit of the new diagnostic technique is the potential to eliminate the need for advanced imaging, something that could make it a valuable tool in middle- and low-income countries lacking these technologies. The team also noted the potential for the test to be used to diagnose TBIs.

“In stroke care, time is brain,” Bernstock said. “The sooner a patient is put on the right care pathway, the better they are going to do. Whether that means ruling out bleeds or ruling in something that needs an intervention, being able to do this in a prehospital setting with the technology that we built is going to be truly transformative.”

With this in mind, the team is now conducting a prospective trial to assess the performance of the stroke detection test when used in the ambulance while a patient is in transport to a hospital. The team has also designed an interventional trial to determine if the test can allow patients to bypass imagining and move directly to interventional care.

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