When combined with clinical scores, a “game-changing” blood test can expedite the diagnosis and treatment of large vessel occlusion (LVO) stroke, potentially saving many lives, new data suggested.
Using cutoff levels of two blood biomarkers, glial fibrillary acidic protein (GFAP; 213 pg/mL) and D-dimer (600 ng/mL), and the field assessment stroke triage for emergency destination (FAST-ED) (score, > 2), investigators were able to detect LVOs with 81% sensitivity and 93% specificity less than 6 hours from the onset of symptoms.
GFAP has previously been linked to brain bleeds and traumatic brain injury.
The test also ruled out all patients with brain bleeds, and investigators noted that it could also be used to detect intracerebral hemorrhage.
“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,” senior author Joshua Bernstock, MD, PhD, MPH, a clinical fellow in the department of neurosurgery at Brigham and Women’s Hospital in Boston, said in a press release.
The findings were published online on May 17 in Stroke: Vascular and Interventional Neurology.
Early Identification Crucial
Acute LVO stroke is one of the most treatable stroke types because of the availability of endovascular thrombectomy (EVT). However, EVT requires specialized equipment and teams that represent a small subset of accredited stroke centers and an even smaller subset of emergency medical facilities, so early identification of LVO is crucial, the investigators noted.
Dr. Bernstock and his team developed the TIME trial to assess the sensitivity and specificity of the blood biomarkers and scale cutoff values for identifying LVO vs non-LVO stroke.
As part of the observational prospective cohort trial, investigators included consecutive patients admitted to the Brandon Regional Hospital Emergency Department in Brandon, Florida, between May 2021 and August 2022 if they were referred for a suspected stroke and the time from symptom onset was under 18 hours.
Patients were excluded if they received thrombolytic therapy before blood was collected or if it was anticipated that blood collection would be difficult.
Investigators gathered information on patients’ clinical data, hematology results, time since last known well, and imaging findings to construct a clinical diagnosis (LVO, non-LVO, ischemic stroke, hemorrhagic stroke, or transient ischemic attack [TIA]).
In addition to the National Institutes of Health Stroke Scale, patients were assessed with the FAST-ED, the Rapid Arterial oCclusion Evaluation (RACE), the Cincinnati Stroke Triage Assessment Tool, and the Emergency Medical Stroke Assessment.
Of 323 patients in the final study sample, 29 (9%) had LVO ischemic stroke, and 48 (15%) had non-LVO ischemic stroke. Another 13 (4%) had hemorrhagic stroke, 12 had TIA (3.7%), and the largest proportion of patients had stroke mimic (n = 220; 68%), which included encephalopathy, hyperglycemia, hypertensive emergency, migraine, posterior reversible encephalopathy syndrome, and undetermined.
The Case for Biomarkers
When investigators looked at those with LVO ischemic stroke, they found the concentration of plasma D-dimer was significantly higher than that in patients with non-LVO suspected stroke (LVO suspected stroke, 1213 ng/mL; interquartile range [IQR], 733-1609 vs non-LVO suspected stroke, 617 ng/mL; IQR, 377-1345; P < .001).