Welcome to the WSC 2021 Interactive Program

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Mobile Stroke Units (MSUs) provide pre-hospital stroke treatment vs EMS transport and subsequent treatment in the ED. BEST-MSU is a prospective trial comparing MSU to EMS management on alternate weeks in patients with suspected acute stroke within 4.5 hrs of onset. Primary outcome was the utility-weighted modified Rankin scale (uw-mRS, range 0 to 1, higher score representing better outcome). The main analysis was of dichotomized uw-mRS >/= 0.91 vs < 0.91 (equivalent to mRS </=1 vs > 1) at 90 days in patients adjudicated tPA-eligible.

We enrolled 1,515 patients at 7 U.S. cities. 617 MSU and 430 EMS patients were tPA-eligible. Median time (min) from stroke onset to tPA was 72 MSU vs 108 EMS; 33% of tPA-eligible MSU pts were treated within 60 min of onset vs 3% EMS. 97% of tPA-eligible MSU patients actually received tPA vs 80% with EMS. Mean 90-day uw-mRS for tPA-eligible patients was 0.72 vs 0.66 for MSU vs EMS (adjusted odds ratio [OR] for MSU vs EMS of uw-mRS >/= 0.91, 2.43; 95% CI, 1.75 to 3.36; p < 0.001). The proportions of tPA-eligible patients achieving mRS of 0 or 1 at 90 days was 55% for MSU vs 44% for EMS. For all enrolled patients mean discharge uw-mRS was 0.57 vs 0.51 for MSU vs EMS (OR, 1.82; 95% CI, 1.39 to 2.37; p< 0.001). All secondary outcomes also favored MSU.

In tPA-eligible acute stroke patients, MSU management resulted in faster and more frequent tPA treatment, and less disability at 90 days.

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Time to treatment is the most powerful modifier for effective recanalizing treatments of acute ischemic stroke. Starting stroke workup already pre-hospital on Mobile Stroke Units (MSU) promises earlier treatment and better triage regarding the most appropriate hospital. The PRE-Hospital Stroke Treatment Organization (PRESTO) is a group of MSU initiatives around the world collaborating in research and further development of pre-hospital stroke care.

After the first description of the MSU concept in 2003, feasibility, safety and effects on shortening time to treatment have been shown in various settings. Recently, two large controlled studies in Germany and the US showed improved functional outcome in patients with acute ischemic stroke by pre-hospital management on MSUs with absolute differences in favorable outcome (mRS≤1) of 9 and 10%. Currently, effects on outcome in patients with intracerebral hemorrhage by earlier blood pressure lowering and anticoagulation reversal are being analyzed. The speed of further MSU implementations in different settings will depend on the results of still ongoing cost-effectiveness evaluations. PRESTO has established common data elements for recording in all MSU programs and is working on the definition of performance benchmarks.

There remain open questions that are currently under investigation: How can the MSU services be reimbursed in different health care settings? Which strategies lead to better stroke recognition and more accurate MSU alerts at dispatch level? Will new stroke treatment innovations be particularly effective when administered in the hyperacute time window on MSUs? Will technological advances help to make pre-hospital stroke (subtype) diagnoses available on normal ambulances?

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Mobile stroke units (MSUs) substantially reduce reperfusion therapy times in acute ischemic stroke (AIS). Phase III trials in the USA and Europe have shown that they improve clinical outcomes, compared with standard of care in emergency departments. MSUs are also an ideal platform for treatment of intracerebral hemorrhage (ICH). The Melbourne MSU has been operational since 2017. In a final diagnosis of stroke, approximately 15% of our cases have intracranial hemorrhages, predominantly ICH, smaller numbers of subarachnoid, subdural and extradural hemorrhages. Around 50% were treated with intravenous anti-hypertensive treatment. Patients were bypassed to a comprehensive stroke centre from the MSU in about one third of cases. Compared to patients with MSU-AIS, patients with ICH had faster onset to emergency call and onset to scene arrival times. We are conducting the STOP-MSU trial which is randomizing patients to tranexamic acid (TXA) versus placebo within 2 hours of the onset of ICH, testing the hypothesis that TXA will reduce ICH growth at 24 hours. This ongoing trial has recruited over 100 patients, about a third from the Melbourne MSU and the remainder from emergency departments in Australia, New Zealand, Taiwan, Vietnam and Finland. MSUs can facilitate ultra-early ICH diagnosis, treatment and triage.