Saving Brain: Landmark DAWN Study Improves Stroke Care
Time Is Brain
Doctors who treat strokes use that mantra because every minute – even second — the brain is deprived of blood damages the brain. In fact, for every minute a large vessel ischemic stroke isn’t treated, a patient can lose 1.9 million neurons, 13.8 billion synapses and 7 miles of fibers, on average. The damage can be devastating. Stroke is a leading cause of disability and the No. 5 cause of death in the United States.
That’s why stroke experts stress the importance of recognizing signs of stroke and taking quick action to receive treatment. Time is also the first question asked when a stroke patient arrives in an emergency department. Doctors count down between the time the patient was last seen well and arrival in an emergency department to determine treatment:
Up to 4.5 hours tPA (clot-busting medication)
6 hours tPA or thrombectomy (surgical removal of clot)
After 6 hours Aspirin and bed rest (medical management)
DAWN Stroke Care Trial
In 2017, a large multi-center trial ended up changing treatment recommendations for patients arriving between 6 and 24 hours after the time last seen well. Called the DAWN trial, it compared the benefit of treatment with thrombectomy versus medical management between 6 and 24 hours.
The trial took place in 20 countries and at 40 to 50 sites in the United States, including CHI Health. The plan was to enroll 500 patients. In January 2017, after more than 200 patients had been enrolled, the trial was abruptly stopped. And for good reason.
It was discovered that thrombectomies were working undeniably well. There was such a powerful cause-to-effect that it was determined medical management was simply not the preferred course of treatment for this group of patients. So the trial ended after 206 enrollees, which is far short of the preset safety target of 250. Such overwhelming results are relatively rare. The DAWN trial may have profound implications for treatment of stroke as it will allow many more patients be treated with thrombectomy. Read full information about the DAWN Trial.
See more about how a thrombectomy works. Questions? Contact the CHI Health Neurological Institute.

These blogs were written by the CHI Health Neurology Team.