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

Prehospital Initiation of Reperfusion Therapy for Acute Ischemic Stroke: Randomized Medico-economic Evaluation of a Mobile Stroke Unit.

ASPHALT is an academic-driven open-label randomized controlled trial of Mobile Stroke Unit (MSU) deployment versus standard care in France, with blinded assessment of efficacy endpoints. 450 patients with confirmed acute ischemic stroke will be recruited over a 3-year period, with 3-month follow-up.

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.

Mobile Stroke Unit, MSU, Intravenous thrombolysis, Emergency Medical Service, Mechanical thrombectomy, Cost-utility, Cost-effectiveness

Deployment of an MSU + conventional ambulance, allowing prehospital CT-scan imaging with intracranial CT angiography. This will allow prehospital intravenous thrombolysis and optimal triage (i.e. accurate identification of patients with large vessel occlusion, who are eligible for mechanical thrombectomy).

ICUR in the lifetime horizon, based on extrapolated results of the Modified Rankin Scale (mRS) at 3 months and incremental costs prospectively collected during the first 3 months

Modified Rankin scale, assessed in a blinded fashion (range, 0 to 6, with 0 indicating no disability, 3 indicating moderate disability, and 6 indicating death)

Incremental Cost-Utility Ratio based on results of the Modified Rankin Scale (mRS) at 3 months and incremental costs prospectively collected during the first 3 months

Incremental Cost-Utility Ratio based on extrapolated results of the Modified Rankin Scale (mRS) at 3 months and incremental costs prospectively collected during the first 3 months

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

Individual participant data (IPD) could be available to other researcher aiming to conduct an IPD-meta analysis of studies of MSU vs. usual care (please see access criteria below).

Data sharing must be accepted by the sponsor and the PI based on a scientific project and scientific involvement of the PI team. Collaboration will be fostered. Data sharing must respect the agreements made with funders. Teams wishing to obtain IPD must meet the sponsor and PI team to present scientific (and commercial) purpose, IPD needed, format of data transmission, and time frame. Technical feasibility and financial support will be discussed before mandatory contractual agreement. Processing of shared data must comply with European General Data Protection Regulation (GDPR).

Turc G, Hadziahmetovic M, Walter S, Churilov L, Larsen K, Grotta JC, Yamal JM, Bowry R, Katsanos AH, Zhao H, Donnan G, Davis SM, Hussain MS, Uchino K, Helwig SA, Johns H, Weber JE, Nolte CH, Kunz A, Steiner T, Sacco S, Ebinger M, Tsivgoulis G, Fassbender K, Audebert HJ. Comparison of Mobile Stroke Unit With Usual Care for Acute Ischemic Stroke Management: A Systematic Review and Meta-analysis. JAMA Neurol. 2022 Mar 1;79(3):281-290. doi: 10.1001/jamaneurol.2021.5321.