• Posted May 20, 2024

New Blood Test Could Spot Dangerous Type of Stroke

MONDAY, May 20, 2024 -- When a stroke hits, "time is brain," doctors say, with neurons beginning to die off in minutes.

Quickly figuring out which type of stroke a patient has been hit with is crucial. Now, an experimental blood test might speed that process along.

A team from Brigham and Women's Hospital in Boston report their test can determine with high accuracy whether or not a patient has suffered a highly lethal type of stroke called large vessel occlusion (LVO).

Once that determination is made, the test gives doctors the green light to use a surgical technique called mechanical thrombectomy to quickly retrieve the LVO clot from any large artery feeding the brain.

“Mechanical thrombectomy has allowed people that otherwise would have died or become significantly disabled be completely restored, as if their stroke never happened,” senior study author Dr. Joshua Bernstock explained in a hospital news release.

“The earlier this intervention is enacted, the better the patient's outcome is going to be," added Bernstock, a clinical fellow in the hospital's department of neurosurgery. "This exciting new technology has the potential to allow more people globally to get this treatment faster.” 

Bernstock's team already knew that different types of strokes produce different "biomarkers" in blood as they occur.

They looked at two proteins in particular: One called glial fibrillary acidic protein (GFAP), which has long been linked to brain bleeds and traumatic brain injury; and one called D-dimer.

Blood tests that measure those proteins help rule out a bleeding stroke, the symptoms of which can be easily confused with an LVO.

Adding the blood test results to what's known as a "field assessment stroke triage for emergency destination" (FAST-ED) score might work together to quickly diagnose an LVO in a patient, Bernstock's group said.

The team tested the theory using data from 323 people who were treated for stroke in Florida in 2021 and 2022.

"Combining the levels of the [blood] biomarkers GFAP and D-dimer with FAST-ED data less than six hours from the onset of symptoms allowed the test to detect LVO strokes with 93 percent specificity and 81 percent sensitivity," the researchers reported.

Ninety-three percent specificity means the diagnostic tool was correct 93% of the time in finding that the stroke was not an LVO, while 81% sensitivity means it correctly spotted an actual LVO 81% of the time.

The new diagnostic strategy may be "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," Bernstock said.

His team believes the test might also help spot or rule out brain bleeds in emergency situations. It might be especially useful in poorer countries where high-tech diagnostic scans might not be available.

The findings were published May 17 in the journal Stroke: Vascular and Interventional Neurology.

The researchers now plan to gauge the effectiveness of the new test in ambulances.

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

More information

Find out more about the different types of stroke at the American Stroke Association.

SOURCE: Brigham and Women's Hospital, news release, May 17, 2024