Posted by Lynn Bronikowski Nov 21 2017
Breakthrough results of an international study could impact tens of thousands of stroke patients in the U.S. who arrive at hospital emergency rooms more than six hours after their stroke symptoms begin.
Current guidelines suggest that after six hours too much time has passed for these patients to be helped by devices that reach into the brain to remove the blood clots cutting off oxygen to the brain.
But a study in the New England Journal of Medicine found that intervening with carefully selected patients could significantly reduce their disability.
“This study emphatically shows that we should not give up on these patients because of arbitrary time guidelines,” said Erol Veznedaroglu, MD, FACS, FAANS, FAHA, chairman of Global Neurosciences Institute, based in Philadelphia, and an investigator of the study.
“In the right patients, we can significantly reduce disability by removing blood clots in the brain even up to 24 hours from the onset of symptoms. This study will force every emergency department in America to rethink the way they treat stroke patients,” said Veznedaroglu said, who also is director of Drexel Neurosciences Institute.
The international, multi-center clinical study, known as the DAWN trial, explored the use of mechanical thrombectomy, which involves a catheter placed in the femoral artery in the leg and threaded up the aorta and into the brain to remove blood clots and restore the blood supply to the brain.
The study examined patients who were known to be well six to 24 hours before treatment. There are many reasons people do not seek immediate medical treatment. Some people do not recognize their symptoms as stroke, are alone and unable to seek help, or are asleep during the stroke.
From September 2014 through February 2017, there were 206 patients enrolled in the trial; 107 were assigned to the thrombectomy group; and 99 to the control group.
About half, or 48 percent, of the patients who had their clot removed showed a considerable decrease in disability. They were independent in their daily lives 90 days after treatment. Just over 13 percent of the medication group had a similar decrease in disability.
The data were so striking the independent Data Safety Monitoring Board overseeing the study recommended the trial be ended early and the results announced. The original aim was to enroll 500 patients.
GNI neurosurgeons were among the first to challenge the treatment window guidelines. In 2015, GNI neurosurgeons, including Mandy J. Binning, MD, found value in clot removal beyond six hours. That study, in the Journal of NeuroInterventional Surgery, found clot removal safe and effective for patients unsure of the onset of symptoms because they were asleep.
“For years we have provided clot retrieval for patients after six hours, and we were often criticized for going against the guidelines. But we did what we believed was best for our patients,” said Dr. Veznedaroglu.
He emphasized that not all patients would be candidates for clot retrieval beyond six hours. Neurosurgeons should intervene when images of the brain, obtained using a specialized CT scan technology, show that salvageable brain exists beyond the clot. Neurosurgeons also must look at the patient’s clinical symptoms.
Each year, some 795,000 Americans experience a stroke. Stroke is the third leading cause of death in the United States. More than 140,000people die each year from stroke, and it’s a leading cause of serious, long-term disability in the United States.
“We desperately need to move forward with innovation and to make sure our clinical guidelines give all our patients the very best shot at returning to the life they had before their stroke,” Dr. Veznedaroglu said.
Global Neurosciences Institute partners with select healthcare systems to provide academic and research leadership in the field of neuroscience.
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