New blood test to detect stroke combines biomarkers with clinical assessment

Stroke is the world's leading cause of disability and the second leading cause of death, but early intervention can prevent serious consequences. A new study by Brigham and Women's Hospital researchers and their colleagues describes the development of a new test that combines blood biomarkers with clinical assessment to accurately identify patients experiencing stroke with occlusion large vessels (LVO).

The results were published in the journal Stroke: Vascular and Interventional Neurology.

"We have developed a revolutionary, accessible tool that can help ensure that more people suffering from stroke are in the right place at the right time to receive critical, life-restoring care," said lead author Joshua Bernstock, MD, Ph. D., MPH, is a clinical fellow in the Department of Neurosurgery at Brigham and Women's Hospital.

Most strokes are ischemic, in which blood flow to the brain is blocked. LVO strokes are an aggressive type of ischemic stroke that occurs when a large artery in the brain is blocked. When the blood supply to the brain is disrupted, the lack of oxygen and nutrients causes brain cells to die within minutes. LVO strokes are serious medical emergencies and require urgent treatment using mechanical thrombectomy, a surgical procedure that removes the blockage.

"Mechanical thrombectomy has allowed people who would otherwise have died or become significantly disabled to fully recover as if the stroke had never occurred," Bernstock said. "The earlier this intervention is performed, the better the outcome for the patient. This exciting new technology has the potential to allow more people around the world to receive this treatment faster."

The research team previously targeted two specific proteins found in capillary blood: one called glial fibrillary acidic protein (GFAP), which is also associated with brain hemorrhages and traumatic brain injury; and the other is called D-dimer.

In this study, they showed that blood levels of these biomarkers combined with the FAST-ED score for in-situ stroke triage could identify LVO ischemic strokes, excluding other conditions such as hemorrhages into the brain. Hemorrhages cause similar symptoms to LVO stroke, making them difficult to distinguish in the field, although treatment for each is significantly different.

In this prospective observational study of diagnostic accuracy, researchers examined data from a cohort of 323 patients admitted with a stroke code in Florida between May 2021 and August 2022. They found that combining GFAP and D-dimer biomarker levels with FAST-ED data less than six hours after symptom onset allowed the test to detect LVO strokes with 93% specificity and 81% sensitivity. Other results included that the test excluded all patients with cerebral hemorrhages, signaling that the technology could also be used to detect intracerebral hemorrhages in the field.

Bernstock's team also sees a promising future use of this affordable diagnostic tool in low- and middle-income countries where advanced imaging techniques are not always available. It may also be useful in the evaluation of patients with traumatic brain injury. Next, they will conduct another prospective trial to measure the test's effectiveness when used in an ambulance. They also developed an intervention trial that uses technology to speed up triage of stroke patients, allowing them to bypass standard imaging and go directly to intervention.

"In stroke treatment, time is the brain," Bernstock said. "The sooner a patient gets on the right path to treatment, the better their outcome will be. Whether that means ruling out hemorrhage or confirming something that requires intervention, being able to do this in a pre-hospital setting with the technology we've developed will be an improvement." truly transformative."