In a development that could help hundreds of thousands of patients each year in the U.S. alone, researchers have discovered that doctors may have more than twice as long to diagnose and treat some stroke victims than previously thought.
The new findings, announced Wednesday at the American Heart Association International Stroke Conference in Los Angeles, show that doctors could have as many as 16 hours to remove a major clot blocking blood flow to the brain while still reducing instances of death and disability. The findings are expected to lead to immediate changes to the Heart Association’s guidelines, which now call for treatment to be given within six hours of the onset of a stroke.
“The big news is that we were all wrong in how we were thinking about how strokes evolve,” said Gregory W. Albers, a professor of neurology at Stanford University Medical Center and lead author of the new paper. While some brain tissue dies in a stroke, collateral blood vessels temporarily take over feeding a larger area that is also starved for blood and oxygen, giving doctors many more hours to save that tissue than they previously believed, Albers said.
So the age-old medical belief that “time is brain” — that millions of neurons die each minute after a stroke — must be reconsidered, he said.
It’s estimated that nearly 800,000 people suffer a stroke each year. Strokes were the fifth-leading cause of deaths in the U.S. in 2016, killing more than 140,000 people and leaving many others with longterm disabilities. The results of Albers’s study, called DEFUSE 3, were so remarkable that researchers cut their work short in order to speed up the process of getting the findings to physicians.
The DEFUSE 3 study looked at 182 people in 38 medical centers who suffered the kinds of blockages in brain arteries that cause 50 to 60 percent of deaths and the most severe kinds of disabilities. About half received typical care, involving blood pressure medication, blood thinners and other medical interventions. The other half had images taken and the clot removal procedure, known as a “thrombectomy,” as well as the medications.
Patients who had their clots removed as part of the study showed improved recovery outcomes and had a reduced mortality rate than patients who were part of a control group.
“We are quadrupling the stroke treatment window today,” Albers said. “It’s going to have a massive impact on how stroke is triaged and assessed.”
Walter Koroshetz, director of the National Institute of Neurological Disorders and Stroke, which funded the new study, said in a news release: “These striking results will have an immediate impact and save people from life-long disability or death. I really cannot overstate the size of this effect.”
The study follows another last year called DAWN, which found that doctors could have as many as 24 hours to conduct a thrombectomy. Together, the studies could have significant benefits for people who suffer strokes either far from treatment centers, or while they’re asleep.
Both studies were published in The New England Journal of Medicine.