A new study published in the New England Journal of Medicine demonstrates both the importance and the challenge of treating people who are at high risk of a stroke.

In the study, led by Dr. Clay Johnston, a neurologist and stroke specialist who serves as dean of the Dell Medical School at The University of Texas at Austin, a team of researchers studied the effects of the drug ticagrelor on people who have suffered a minor ischemic stroke or what is known as a transient ischemic attack, or TIA.

The study, which looked at more than 13,000 patients in 33 countries, did not find that ticagrelor was better than aspirin, the current standard, in reducing the risk of stroke, heart attack, or death in patients presenting with TIA or minor stroke. About 6.8 percent of patients in the study who were taking ticagrelor suffered a stroke, heart attack or death within 90 days of the initial attack, versus about 7.5 percent of patients who were taking aspirin. It also demonstrated that ticagrelor is about as safe as aspirin even though it works in the body in a completely different way. The European biopharmaceutical company AstraZeneca sponsored the study.

"There are still too many strokes afflicting patients with TIA and minor stroke, whether they are taking ticagrelor or aspirin," Johnston said. "While this study doesn't necessarily show that we can prevent strokes among this group any better with this one drug, it does open the possibility that combinations of drugs could reduce the risks that these vulnerable patients face."

Minor strokes account for about a third of total strokes, and TIAs are about as frequent - about 250,000 TIAs and about 200,000 minor strokes are diagnosed each year in the United States. Both involve a blockage in a blood vessel, leading to stroke symptoms that either resolve or become permanent. Without treatment, roughly 10 percent of patients who experience TIA or minor stroke suffer a stroke just weeks or months after the initial attack, Johnston said.

Johnston is scheduled to discuss the study at the European Stroke Organisation Conference 2016 this week in Barcelona, Spain.

Stroke prevention and treatment is a growing focus of the Seton-Dell Medical School Stroke Institute, a collaboration with the Seton Healthcare Family meant to transform care in Central Texas and catalyze research on treating and preventing stroke.

Seton is working with Dell Medical School to provide specialized stroke in-patient units at the new Dell Seton Medical Center at The University of Texas, which opens in 2017.

"Getting evaluated by a stroke subspecialist here in our community will get a patient the most appropriate treatment more quickly - and it will lead to better outcomes for stroke patients," said Dr. Steve Warach, director of the Stroke Institute, who also is slated to address the conference in Barcelona. "We also want to develop therapies for stroke situations that now don't have any therapies. Working with other U.S. researchers, we must discover and develop ways to effectively treat stroke patients of all kinds across the region."

Ticagrelor versus Aspirin in Acute Stroke or Transient Ischemic Attack. S. Claiborne Johnston, M.D., Ph.D., Pierre Amarenco, M.D., Gregory W. Albers, M.D., Hans Denison, M.D., Ph.D., J. Donald Easton, M.D., Scott R. Evans, Ph.D., Peter Held, M.D., Ph.D., Jenny Jonasson, Ph.D., Kazuo Minematsu, M.D., Ph.D., Carlos A. Molina, M.D., Yongjun Wang, M.D., and K.S. Lawrence Wong, M.D., for the SOCRATES Steering Committee and Investigators. New England Journal of Medicine. DOI:10.1056/NEJMoa1603060. Published online May 10, 2016.