Results stemming from a pilot study involving 11 hospitals in four different regions have shown that a portable medical device using a portion of the same technology that tracks a smart phone user’s movement can be utilized by emergency medical technicians in the field to detect a major stroke, with performance characteristics possibly superior to currently used prehospital detection methods.
Wayne State University School of Medicine Associate Professor of Emergency Medicine James Paxton, M.D., M.B.A., leads the research, with the support of 18 sub-investigators throughout the country. He summarized the results of an initial pilot study, "hEad Pulse for Ischemic StrOke DEtection Prehospital Study During the COVID-19 Pandemic,” or EPISODE-PS-COVID, during a plenary session of the American College of Emergency Physicians Research Forum, held Oct. 9-12 in Philadelphia. Of 448 abstracts reviewed by judges, his tied first for Best in Show at the meeting.
“Doctors have known for a long time that we need a good way to diagnose strokes quickly before the patient gets to the hospital so that we can treat them rapidly after they arrive to the hospital. At present, we use ‘clinical stroke scales,’ which are based mostly upon clinical findings like weakness of the arms, legs and face, or speech changes,” Dr. Paxton said. “The problem is that no existing clinical stroke scales are both highly sensitive and specific, so you always have a trade-off between being really good at detecting strokes and being right when the test is positive.”
Often debilitating, large vessel occlusion ischemic strokes represent only one-third of acute ischemic strokes in the United States, yet are associated with two-thirds of post-stroke dependence and greater than 90% of post-stroke mortality.
Over a 21-month period during the COVID-19 pandemic, 594 patients in Detroit, Kalamazoo, Saginaw and San Francisco received HarmonyTM 5000 device placement by pre-hospital EMS personnel, of which 158 provided informed consent to move forward in the study.
“Our results show that the HarmonyTM 5000 device seems to have a much higher sensitivity than one of the clinical stroke scales that lots of people use, with similar specificity for LVO stroke,” Dr. Paxton said. “If that is true, this device will probably be better at correctly identifying LVO stroke than the clinical tests that people are currently using to detect these major strokes in the field. That could dramatically change how quickly LVO stroke victims can get thrombectomy, because it would allow ambulance crews to take people straight to thrombectomy-capable centers instead of taking them to other hospitals. It might also let the ambulance team call ahead to the hospital and tell them that an LVO patient is on the way, so that they can start preparing for the patient’s arrival quicker.”
An endovascular thrombectomy – pulling the clot out of the brain with a thin tube inserted into the groin and advanced up into the brain – is now the standard of care treatment for LVO stroke, and it seems to work a lot better than thrombolytic therapy alone, Dr. Paxton said.
“The problem is that the benefits of thrombectomy are very dependent on how quickly the clot is removed, and patients who have a long delay from the time of clot formation to thrombectomy don’t do as well as patients who get thrombectomy right away. It is very important that patients with LVO stroke get thrombectomy as soon as possible. As they say, ‘time lost is brain lost,’” he added.
The HarmonyTM 5000 device is an investigational device invented by MindRhythm Inc., based in Cupertino, Calif. The device incorporates accelerometers into a headset placed on the patient’s head. It measures a patient’s head pulse – tiny movements blood makes through the brain’s blood vessels while the heart beats. Dr. Paxton compared the technology to checking a wrist pulse, but in greater detail.
“Of course, I am excited to receive this award from what is arguably the pre-eminent scientific conference in emergency medicine. Clinical researchers can work their entire career without winning an award like this. But the truth is, we are doing world-class research like this every day at WSU, especially in the Department of Emergency Medicine,” Dr. Paxton said. “I think the award is a reflection of the importance of this breakthrough device, and the huge scale on which we were able to operate. As far as I know, this is the largest pre-hospital stroke detection device trial that has ever been attempted, and is the first ever study evaluating the clinical use of a cranial accelerometry device for LVO stroke detection in the pre-hospital environment.”
His collaborators include WSU School of Medicine’s Associate Professor Howard Klausner, M.D.. Assistant Professor of Emergency Medicine John Wilburn, M.D; and Assistant Professor Stefanie Wise, M.D.; Western Michigan University Homer Stryker, M.D. School of Medicine Radiologist K. Derek Kreitel, M.D., and Clinical Assistant Professor of Medicine Larry Morgan, D.O.; University of California at San Francisco Associate Professor of Emergency Medicine Debbie Madhok, M.D.; California Pacific Medical Center Department of Neurology’s Nobl Barazangi, M.D.; Ascension St. Mary’s of Saginaw, Mich., Department of Emergency Medicine Steven McLean, M.D.; and WSU Associate Professor Robert Dunne, M.D.
The research team led by Dr. Paxton is now completing a second, larger study, called EPISODE-Verification (EPISODE-VS), adding four more geographical regions to the initial pilot areas, including Indianapolis, Salt Lake City, Naples, Fla., and Memphis, Tenn. “This will give us a wider range of patients and hopefully validate our findings in the pilot trial,” he said. “The real heroes of this study are the ambulance crews who enrolled the patients and the research associates who collected the data and followed up on the patients after they arrived at the hospital. Literally hundreds of people from dozens of organizations carried the burden of completing this study on their shoulders for almost two years, and we made it across the finish line with outstanding results. I couldn’t be prouder of how we all pulled together to get this project completed. The best part of my experience as principal investigator of this study was seeing what amazing things we can all do when we work together to help improve patient care. I really gained a deep appreciation for the work that my colleagues in the pre-hospital and in-hospital environments do every day to advance our field.”