The New England Journal of Medicine has published the results of the BEST-MSU study, the most compelling evidence yet that mobile stroke units in fact deliver the benefits their proponents have for years believed they would.
Data from patients treated in the UCHealth Mobile Stroke Treatment Unit (MSTU), just the third mobile stroke unit in the United States when it began making its urgent house calls in January 2016, informed the study; Dr. William Jones, the CU School of Medicine and UCHealth neurologist who championed the MSTU, is a coauthor.
“Time is brain” is the stroke-treatment mantra for a reason. For every second that treatment is delayed, an average of more than 30,000 neurons die. The odds of death or disability rise with each passing minute. Mobile stroke units bring hospital-grade stroke diagnosis and treatment with clot-busting tissue plasminogen activator (tPA) straight to patients, saving precious minutes – an average of 36 minutes, according to the new study, based on data from seven U.S. mobile stroke units.
Big mobile stroke unit study
The UCHealth Mobile Stroke Treatment Unit, which alternates between Aurora and Colorado Springs, contributed data on 100 patients to the new study, 69 of them treated in the MSTU and then the hospital, 31 of them just in the hospital. The overall study included 1,047 patients eligible for tPA (only ischemic strokes, caused by blood clots, are treatable with tPA; hemorrhagic strokes from burst blood vessels are treated differently), of which 617 were treated with tPA in a mobile stroke unit and 430 who were treated in the hospital after an ambulance call.
The most striking result: patients treated with tPA in a mobile stroke unit were nearly two-and-a-half times more likely to have a good outcome – either no lingering symptoms at all or no significant disability despite symptoms – than those rushed by ambulance to a hospital, diagnosed there, and given tPA.
Jones expects the study to reverberate through the world of stroke treatment.
“There are around 20 mobile stroke units in the United States and more worldwide,” Jones said in an email. “It is likely that the growth may accelerate with the publication of this study.”
The UCHealth MSTU looks like an ambulance but is much more. It rolls with a stroke-trained critical care nurse, a paramedic, a CT technologist, and an emergency medical technician. Jones and other expert stroke neurologists connect in via a telehealth robot, assessing the patient as well as CT scans and other data coming over cellular wireless network connections. If it’s an ischemic stroke (that is, caused by blockage), the neurologist can give the go-ahead for administering tPA, and the clinical nurse specialist infuses it as the MSTU heads to the nearest hospital.
David Ornelas, the UCHealth Mobile Stroke Treatment Unit’s nurse manager, says the MTSU has averaged 90 transports a year, of which about one-third involve tPA treatments. Bob Waddell was among them.
‘I’m having a stroke’
In July 2018, the then 59-year-old civil engineer was sitting on the edge of his back deck and hosing off his shoes after pulling weeds in his Colorado Springs backyard when he fell to the ground and couldn’t get up. His left hand had gone numb. He had to fumble for a cell phone in his left pocket with his right hand to call a neighbor. His slurring was such that the neighbor asked him if he’d been drinking.
I’m having a stroke right now, Waddell realized. I’ve gotta call 9-1-1.
Colorado Springs Fire Department paramedics arrived within a couple of minutes and the MSTU pulled into his driveway minutes after that. The radiation technologist did a CT scan and a UCHealth neurologist, assessing the scan and the patient himself via the telehealth robot, gave the go-ahead for tPA. At UCHealth Memorial Hospital Central, an endovascular surgeon considered the results of additional in-hospital CT scans and whisked Waddell into surgery within 35 minutes of his arrival. There, the surgeon snaked a catheter up through Waddell’s femoral artery near the groin to grab and remove a clot too big for tPA to dissolve.
Waddell was back at his job assessing the integrity of dams within weeks; more than two years later, he is as healthy as before the stroke.
“The amount of brain loss that I suffered was minimized tremendously by that mobile stroke unit,” Waddell said. “They were able to diagnose and give me the tPA – without that, the stroke could have killed me. That 10- or 15-minute ride to the hospital – that’s critical time. I would have suffered more brain damage had that mobile stroke unit not been available.”
More to come, backed by mobile stroke unit study
The results published in the New England Journal of Medicine represent a huge step in backing up intuition and anecdotes with hard-earned, evidence-based data regarding the tremendous good mobile stroke units can do. Jones says more data is on the way.
The current study also considered the overall costs of mobile stroke unit patients versus hospital-only treated patients. Jones says that cost data should be ready by the American Heart Association/American Stroke Association International Stroke Conference scheduled for February 2022.
In addition, the UCHealth MSTU team is poised to participate in an international study evaluating the early treatment of patients with hemorrhagic strokes with a clotting agent – essentially, the opposite approach of giving tPA to those with ischemic strokes. The team is also doing a local study analyzing blood samples collected from MSTU patients to look for early biomarkers of stroke. They’re also preparing to add CT angiography on the MSTU, a type of CT scan that can identify and help pinpoint the location of blood clots. That would speed the pace of clot removal for patients like Bob Waddell even further.
Taken together, it’s clear that Jones’s idea back in 2014 to pitch UCHealth on spending a cool $1 million on a juiced-up ambulance for stroke care – and UCHealth’s decision to make it happen – was one that has saved lives and preserved quality of life, and will continue to do so going forward.