CINCINNATI—Stroke is the third leading cause of death and the leading cause of major disability in the United States. Successfully treating ischemic stroke is dependent on how quickly treatment is given to break up the blood clots that clog key vessels and cause this type of disease.
University of Cincinnati (UC) neurologist Pooja Khatri, MD, says that as new treatment methods have become available, little data has been gathered about how long these treatments can be used after stroke onset to produce good outcomes.
UC’s neurology department has been involved in developing stroke treatment since the early studies of tissue plasminogen activator (t-PA), the only Food and Drug Administration-approved treatment for acute ischemic stroke. Intravenous t-PA has been found to be effective if administered within three hours of stroke onset, and more effective if given sooner. But how the timing of starting this medicine in a stroke patient relates to the timing of when the blood vessel is actually opened has not been known.
In recent years, physicians have started investigating methods for directly dissolving or removing blood clots using a catheter in brain vessels, called the intra-arterial approach. Evidence has suggested that this method may be more effective than intravenous t-PA, but no data was previously available on how much time matters in this setting.
Khatri, an assistant professor of neurology and member of the Neuroscience Institute at UC and University Hospital, had concerns that, at later treatment times, the brain may become irreversibly damaged, and the risks of the procedure would outweigh any benefit of restoring blood flow.
She and a team of researchers analyzed data from a multicenter international stroke trial coordinated by UC, which was testing the safety of low-dose intravenous t-PA followed by intra-arterial treatments. They analyzed how the timing of when blood flow was restored affected the chance of a good recovery.
Khatri’s team found that the chance of a good outcome after opening a blood vessel became progressively less over time, and by about seven hours after stroke onset, the chance for a good outcome approached that of someone who had received no treatment at all.
“This is the first clear evidence that time is a strong determinant of outcome, even if a blood vessel is successfully opened,” says Khatri. “It reinforces the notion that stroke treatments and stroke health care delivery must emphasize speed.”
Results of their study were presented today at the annual International Stroke Conference in New Orleans. For her work, Khatri was presented with the Robert G. Siekert New Investigator Award.
The Siekert Award is presented annually in honor of Robert Siekert, founding chairman of the American Heart Association’s International Conference on Stroke and Cerebral Circulation. The award encourages new investigators to undertake or continue stroke-related research.
She is the second UC investigator to receive this award. Dan Woo, MD, associate professor of neurology, received the honor in 2004.
Coauthors for Khatri’s study include Todd Abruzzo, MD, radiology, Joseph Broderick, MD, neurology, and Thomas Tomsick, MD, radiology, all from UC, and Sharon Yeatts, PhD, from the Medical University of South Carolina.
The Neuroscience Institute is a collaborative effort of nine academic departments at the UC College of Medicine, the University Hospital and independent physician practice groups. The institute is dedicated to patient care, research, education and the development of new medical technologies.