Hello. My name is Dr. Mark Alberts, Vice Chair of Clinical Affairs at UT Southwestern Medical Center in Dallas, Texas.
Today I want to talk about a study published in the April 23/30 issue of JAMA. In fact, this issue of JAMA includes several interesting stroke studies, but today I will discuss the STEMO study, which was conducted in Germany.
These investigators converted an ambulance into, essentially, a mobile stroke unit. The ambulance was staffed by a neurologist and included a portable CT scanner and a telemedicine interface. This allowed them to go into the community when there was a call about a stroke; assess the patient in the ambulance; conduct a history, physical, and CT scan; and begin therapy in the ambulance before the patient reached the emergency department. To divide the patients into treatment and control groups, the special ambulance was used during some weeks and the standard ambulance during other weeks. At the end of the day, they had looked at a large cohort of over 6000 patients.
Measuring the Benefits
From my reading of the article, overall about 10% of patients received IV tissue plasminogen activator (TPA), and many of them got it in the field in the ambulance. They found that during the time when they had this mobile stroke unit available, they could give TPA much more rapidly, and in some cases the time from alarm to treatment was only 51 minutes. That is not door-to-needle time; that is symptom onset or when the alarm was first activated to treatment time -- 51 minutes. In general, they saved about 25 minutes when they had the emergency stroke unit available compared with when they did not. Hemorrhage rates did not go up. The percentage of patients treated with TPA did increase and the time to treatment went down.
What about overall outcomes? These were not reported in the study, or at least not yet. What about the cost-effectiveness of this approach? This mobile ambulance and the CT, just the infrastructure, cost well over $1 million. Was it cost-effective to have a neurologist riding around Berlin and other cities? That analysis has yet to be reported.
This is a very interesting concept that clearly can be done in a safe and effective manner. But is it cost-effective across a large population? Would it actually increase the percentage of patients overall who get TPA? Probably yes, by getting to those patients who would be outside the window if they went to the emergency department and had delays there versus having all the workup completed in the ambulance while being transported. Does it make a difference in terms of overall functional outcomes? If we believe that time is brain, the answer is yes, but to date, this study has not proven that. So stay tuned. There is more to come on this exciting aspect.