Clinical trial seeks to extend stroke treatment time windowDec. 8, 2016, 10:08 AM
The Vanderbilt Stroke Center will participate in a national clinical trial to investigate whether thrombectomies can benefit stroke patients when performed beyond the currently recommended window of time for intervention.
A thrombectomy, which entails threading a catheter with a stent retriever through a main artery and directing it to the brain to remove a blood clot, is most commonly performed up to six hours after the onset of a stroke. DEFUSE 3, a multicenter trial launched this year, seeks to determine if the intervention benefits patients up to 16 hours afterward.
In many cases, such as “wakeup” strokes that actually occur while people are sleeping, the time of symptom onset cannot be determined. Nor can the time be determined when people are found alone.
“What the study is really asking is whether opening a blockage can still be effective for certain people even if the symptoms have been present for an extended period of time,” said Rohan Chitale, M.D.
Chitale, a neurosurgeon, is working closely with Michael Froehler, M.D., Ph.D., a neurologist who is the site principal investigator, other colleagues at the Vanderbilt Stroke Center and imaging specialists to begin enrolling in the trial by Jan. 1, 2017. The trial relies heavily on computed tomography (CT) perfusion imaging to detail what areas of the brain are salvageable.
“We want to find answers to these important questions to advance the way we care for our stroke patients,” said Jessica Collins, manager of Surgical Core of Research Resources.
The multicenter study will randomize up to 476 patients over four years with acute ischemic anterior circulation strokes due to large artery occlusions.
“To be on the brink of new data and understanding of how to treat the most complicated stroke patients is truly remarkable,” said Kiersten Espaillat, DNP, APN, stroke program coordinator.
The first stent retriever for performing thrombectomies was approved by the U.S. Food and Drug Administration in 2004. Since that time the medical devices have improved, and clinical studies have shown that stroke patients benefit from thrombectomies for large vessel occlusions, with or without concomitant administration of intravenous tissue plasminogen activator (tPA).
The DEFUSE 3 study will involve patients discovered six to 16 hours after the stroke occurred.
“Patients who qualify will be randomized to either no interventional treatment as a control group versus interventional treatment to see if extending the window will actually benefit some groups of patients,” Chitale said.
The study will rely on imaging technology instead of blood tests to identify patients who might benefit because there are no known biomarkers to determine when a stroke occurs.
Interim analyses of the multicenter study will be conducted once enrollment reaches 200 and 340 patients.
“In the past, we couldn’t do anything for these kinds of patients,” Chitale said. “They would certainly end up in a nursing home or worse. Now, if there is a significant percentage of patients we could prevent from having that fate, that’s what our goal is.”
Vanderbilt University Medical Center is a Joint Commission-certified Advanced Comprehensive Stroke Center, the highest certification level given. The Vanderbilt Stroke Center rapid response for treating stroke patients has received the American Stroke Association’s Honor Roll-Elite Plus recognition. This designation is given in recognition for performance beyond the requirements for the American Stroke Association’s Gold Plus Quality Achievement Award.