Interview with two of the study authors Professor Heinrich Audebert (Charité-Universitätsmedizin Berlin, Germany) and Professor Martin Ebinger (Charité-Universitätsmedizin Berlin and Medical Park Berlin Humboldtmühle, Germany)
1. WHAT DID YOU SET OUT TO STUDY?
We have known from several studies initially by the Saarland University (Homburg/Germany) group and later on from Berlin that Mobile Stroke Units shorten treatment times to thrombolysis in acute ischemic stroke. What was lacking was the evidence for improved functional outcome – as measured with the modified Rankin Scale after three months.
2. WHY THIS TOPIC?
The association between shorter onset-to-needle times and better outcomes has become common knowledge in the stroke community and beyond. Nevertheless, whether or not the resources going into setting up and running a Mobile Stroke Unit system are a wise investment has been questioned. Definite answers to these questions require the proof of improved outcomes. This will allow for more comprehensive cost effectiveness analyses with fewer assumptions.
3. WHAT WERE THE KEY FINDINGS?
The B_PROUD study, short for Berlin Prehospital Or Usual Delivery of stroke care, showed higher rates of thrombolysis, shorter times from onset to thrombolysis and clearly better functional outcomes after three months for stroke patients for whom an Mobile Stroke Unit was dispatched as compared to patients for whom no Mobile Stroke Unit was available at time of dispatch.
4. WHY IS IT IMPORTANT? Or HOW MIGHT THESE RESULTS IMPACT CLINICAL PRACTICE?
Our results suggest that at least in metropolitan areas, the use of Mobile Stroke Units will improve outcomes. This should give momentum to pending decisions regarding integration of Mobile Stroke Units in the emergency system of other cities. We hope that the results of our study stimulate the teams around the world who are working on improving acute stroke care, especially in the prehospital setting. Those centers who operate Mobile Stroke Units have joined an international organisation called PRESTO, which has regular meetings and established a great collaboration with many scientific activities. Most recently, for example, we were all very excited to hear that our Australian partners received a $40 million grant for their Stroke Golden Hour project based on air ambulances with brain scanners. All these global activities together with thorough cost-effectiveness analyses will help to ease the global burden of stroke.
5. WHAT SURPRISED YOU MOST?
The most surprising finding was that our research revealed a logistic shortcoming in Berlin. We had expected that the CT angio aboard our Mobile Stroke Units together with prenotification of the receiving cath lab would shorten onset to time of groin puncture. We expected that this would add extra benefit in cases of large vessel occlusion. However, it turned out that many interventional radiologists were hesitant to use CT-angios from the Mobile Stroke Units as there was no imaging of the aortic arch included. So, time was lost by a repeat scan in some of these centers before they were rushed to the cath lab. In the meantime, most interventionalist got used to do without it. But this was one lesson from our study we had to learn the hard way.
6. WHAT’S NEXT FOR THIS RESEARCH?
We are eagerly awaiting further studies, ideally randomized, such as the one by James Grotta and colleagues from Houston, Texas, USA, to corroborate our findings. Furthermore, there is urgent need to see what Mobile Stroke Units can achieve in different settings than a city like Berlin, Germany. What could be the impact in rural areas? Will regions like the north of Norway with fjords cutting into the landscape need different – air-bound – approaches? Will traffic in Singapore allow for time savings with a Mobile Stroke Unit? Will new and cheaper technical innovations enable pre-hospital stroke care in developing countries including Africa? Will some Latin American countries prefer telemedicine in Mobile Stroke Units in order to staff Mobile Stroke Units with less medical personnel that is needed in hospitals as well? For all these questions, further research will provide answers.
7. IS THERE ANYTHING YOU’D LIKE TO ADD?
As always, this was a huge team approach. We thank the Berlin Fire Brigade, who runs the entire EMS of the city, and we thank all team members on each of the three Mobile Stroke Units in Berlin for their ongoing efforts to improve outcomes of stroke patients day in, day out.
Prof Audebert- coordinates the prehospital stroke research in Berlin/Germany. HJA reports lecture honoraria received by Boehringer Ingelheim