LOS ANGELES—Specialized mobile stroke unit ambulances outfitted with CT machines appear to make a difference in how well patients recover from stroke, researchers reported here at the American Heart Association/American Stroke Association International Stroke Conference 2020.
Heinrich Audebert, MD, professor of neurology at the Center for Stroke Research at Charité-Universitätsmedizin in Berlin and the senior author of the Berlin Prehospital Or Usual Delivery trial, reported that 63 percent of patients treated in the mobile stroke unit were discharged with a modified Rankin Scale score of 0–2 compared with 57 percent of the patients who were treated with usual care, but not in a stroke unit vehicle. That translated to a 26 percent reduction in disability among those patients, which was statistically significant (p=0.003).
In the study, 749 patients were assigned to treatment based on the availability of three mobile stroke units in the metropolitan area of Berlin, and their outcomes were compared with 794 patients who received conventional care.
The mobile stroke units in Berlin are staffed with emergency medicine neurologists and equipped with a CT scanner and a lab designed to enable specific stroke treatment at the scene.
Dr. Audebert said 60 percent of patients assigned to the mobile stroke unit received clot-busting treatment with alteplase if a mobile stroke unit was available, compared with 48 percent of patients who received conventional treatment in the hospital; the time to treatment was shortened by an average of 20 minutes when a mobile stroke unit was dispatched; and the use of a mobile stroke unit reduced the likelihood and severity of disability and death at three months by 26 percent.
The difference between standard care and the mobile stroke units was not statistically significant, however, for the co-primary endpoint—that is, that patients required aid in getting around or were confined to long-term nursing care or had scores of 4–5 on the modified Rankin Scale. Dr. Audebert reported that 12.6 percent of the patients treated in the mobile stroke unit met the endpoint compared with 13.3 percent of the patients who received usual care (p=0.057).
The researchers reported that 7.1 percent of the patients who were in the mobile stroke unit died compared with 8.9 percent of the patients in the usual care group.
"While we had anticipated better outcomes in the patients treated in the mobile stroke units, we are amazed by the magnitude of the effects," Dr. Audebert said. "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."
Since treatment within the first hour of symptom-onset happens rarely in conventional care, Dr. Audebert said health care providers should consider ways to optimize treatment so it can begin while in route to the hospital.
"Stroke treatment is more effective the earlier it starts," he said. "Just waiting until the patient arrives at the hospital is not enough anymore."
Commenting on the study, Mitchell S. Elkind, MD, MS, FAAN, professor of neurology at Columbia University and president-elect of the American Heart Association, told Neurology Today At the Meetings, "This was one of the most exciting studies that were presented at the meeting because it has the potential to really change how we arrange our systems of care."
However, Dr. Elkind said that those changes are not just as simple as retrofitting ambulances. "You really can't just put a CT scanner in an ambulance. You have to design a vehicle from the ground up and it may not be necessary that all ambulances have these capabilities."
"While the results of the study were impressive, this still was done in just one city in Germany, and how it would work in the United States or other parts of the world remain a question. Whether it can work in urban, suburban, or in rural areas are things that have to be worked out. There are also questions about cost-effectiveness. These are not cheap vehicles; they will cost in the neighborhood of $1 million each, plus there is the cost of staffing them. We have to show that it is cost-effective if we are going to implement the use of these vehicles widely."
"We now have three mobile stroke units at New York Presbyterian Hospital, one on the east side of New York City, one on the west side, and one in Queens. I am not sure that we have proven yet that they can operate without philanthropy," he said.
Dr. Elkind said that the failure of the trial to show a significant impact in case of very devastating strokes was somewhat expected. "We saw in this trial that the mobile stroke unit decreased the time to getting thrombolysis by 20 minutes and increased the number of patients who received thrombolysis by 12 percent, but in a very devastating stroke—the modified Rankin Scale scores of 4–5—those differences in time shift may not be enough to make a difference in these individuals," he said.
The study was funded by the German Research Foundation and the Ministry of Education and Research. Dr. Audebert disclosed he has received research grants from Pfizer and honoraria from Pfizer, Bristol Myers Squibb, Bayer Vital, Boehringer Ingelheim, Takeda, and Novo-Nordisk. He has also receive research grants from Stiftung Deutsche Schlaganfall-Hilfe, Bundesministerium für Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft, and Innovationsfonds des Gemeinsamen Bundesausschusses. Dr. Jessup had no disclosures.
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ISC Abstract LB5: Ebinger M, Siegerink B, Kunz A, et al. Effects of pre-hospital acute stroke treatment as measured with the modified Rankin Scale; the Berline Pre-hospital Or Usual care Delivery (B_Proud) trial.