Acute Stroke: Prehospital Versus In-HospitAL Initiation of Recanalization Therapy- ASPHALT

Instead of the traditional approach of waiting until the patient arrives at the hospital to perform brain imaging and start reperfusion therapies, mobile stroke units (MSUs; ambulances equipped with a CT scanner) now allow pre-hospital initiation of intravenous thrombolysis (IVT). Two large non-randomized clinical trials (B_PROUD & BEST-MSU) have recently shown that MSU use leads to improved functional outcomes at 3 months in specific settings. However, MSUs have been criticized because of their cost and a lack of evidence of a significant reduction in the time between symptom onset and mechanical thrombectomy, which is the cornerstone of treatment of patients with large vessel occlusion.

We hypothesized that compared to usual care, the deployment of a MSU would result in an incremental cost-utility ratio ≤50,000 euros per QALY in the lifetime horizon, even in an area with many thrombectomy-capable centers..

Academic-driven open-label randomized controlled trial of Mobile Stroke Unit (MSU) deployment versus standard care in France, with blinded assessment of efficacy endpoints. Randomization will be performed on an individual patient basis (randomization of MSU deployment at dispatch). 450 patients with confirmed acute ischemic stroke (emergency call ≤6 hours after onset) will be recruited over a 3-year period, with 3-month follow-up. Costs and clinical outcomes will be collected prospectively during the study period and used to extrapolate the incremental cost-utility ratio over a lifetime horizon.

Inclusion criteria

• Emergency call to one of the two following emergency medical service (EMS) dispatch centers : SAMU (Service d'Aide Médicale Urgente) or BSPP (Brigade des Sapeurs Pompiers de Paris), between 08:00 and 18:00, 5 days a week (Monday to Friday).
• Suspected acute stroke according to a dispatcher stroke identification algorithm, adapted from the ROSIER scale
• Symptom onset-to-randomization time ≤ 6h
• Patient located within the predefined catchment area of the MSU
• MSU available at the time of the EMS call
• Informed consent (as approved by the ethics committee, informed consent will be obtained after randomization: at the arrival of the MSU (intervention group), or at hospital arrival (control group))

Exclusion criteria

• Patient confined to be more than 50% of waking hours
• Unknown or uncertain onset time (e.g. wake-up stroke)
• Medical history of epilepsy
• Recent epileptic seizure (<12 hrs)
• Suspicion of pregnancy
• Parturient or breastfeeding woman
• Patient already participating in another interventional study, which could influence the mRS at 3 months.
• Patient under guardianship or curatorship
• Patient not affiliated to French Social Security