Functional Outcomes Improved by Mobile Stroke Units

Heinrich Audebert, MD

Functional outcomes for patients with acute ischemic stroke who are free from contraindications for thrombolysis and thrombectomy were significantly improved by mobile stroke units (MSUs) compared with those who did not have MSU availability, according to data presented at the 2020 International Stroke Congress (ISC).^1-2

Investigators documented higher thrombolysis rates in patients with MSU availability versus without (60% vs. 48%; standardized mean difference, 0.24; P <.001), as well as faster median alarm to treatment times (50 min [interquartile range (IQR), 43—64] vs. 70 min [IQR, 59–85]; standardized mean difference, 0.59; P <.001).

Patients treatment times were shortened by 20 minutes when a MSU was dispatched. Notably, at 3-months post admission, the likelihood and severity of disability and death was reduced by 26%.

“While we had anticipated better outcomes in the patients treated in the mobile stroke units, we are amazed by the magnitude of the effects. It is obvious that clot-busting treatment is most effective if it is applied in the ultra-early phase of stroke—ideally within the first or ‘golden hour’ of symptom onset,” said lead study author Heinrich Audebert, MD, professor of neurology, Center for Stroke Research, Charité Universitätsmediz, said in a statement.

READ MORE: Poststroke Seizures Associated With Increased Risk for Functional Disability, Death

The prospective, quasi-randomized trial included 1543 patients, aged 18 years or older with acute cerebral ischemia, who requested medical dispatch. Investigators compared primary and co-primary outcomes of each patient who were transferred to a hospital with and without a MSU.

Patients included in the study had code strokes with onset-to-alarm <4 hours at the dispatch center and emergency calls within an MSU catchment area. Those excluded from the trial had symptom resolution before ambulance arrival, as well as patients with simultaneous absolute contraindications for both thrombectomy and thrombolysis.

Using the modified Rankin Score (mRS), patients’ primary outcomes were scored on a 0-6 scale, with ‘0’ indicating no neurologic deficits, and 6 indicating death at 3-month after index-event. The additional co-primary outcome classified patients into 3 categories following their departure of hospitalized care. Those who had mRS scores between 0-3 were labeled with a ‘1’, indicating able to ambulate. Patients classified with ‘2’ indicated severe disability (mRS 4-5) or living in institutional care, and a ‘3’ for those who died following care.

Of the 1543 patients (mean age [SD]: 74 years [13]), 1338 (87%) participated in primary outcome assessment and 1506 (98%) had co-primary outcomes assessed. In the primary outcome, the odds ratio of disability and death at 3 months was significantly reduced by MSU availability. On the other hand, MSU availability did not reduce the odds ratio of disability and death in the co-primary outcome (0.80; 95%- CI, 0.61-1.06).

“Stroke treatment is more effective the earlier it starts,” Audebert said. “Just waiting until the patient arrives at the hospital is not enough anymore.”

For more coverage of ISC 2020, click here.

REFERENCES

1. Effects of pre-hospital acute stroke treatment as measured with modified rankin scale; the Berlin — prehospital or usual care delivery (B_PROUD) trial. Presented at: 2020 International Stroke Conference. February 19-21, 2020; Los Angeles, CA. Abstract LB2

2. Fast treatment via mobile stroke unit reduced survivor disability. Published February 20, 2020. newsroom.heart.org/news/fast-treatment-via-mobile-stroke-unit-reduced-survivor-disability. Accessed February 20, 2020.