You are here
Study Identifies Patients at Higher Risk of Second Stroke
The risk of recurrent stroke is higher in patients who have low blood flow to the back of the brain, a 6-year multicenter trial has found, and the condition can be visualized using specialized software developed at the University of Illinois at Chicago (UIC) College of Medicine that analyzes blood flow using standard magnetic resonance imaging.
Principal investigator Dr. Sepideh Hanjani presented the results of the VERiTAS (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) trial on February 12 at the International Stroke Conference, held in Nashville, Tennessee.
Patients with blockage of the blood vessels that supply blood to the back of the brain –– a condition known as vertebrobasilar disease (VBD) –– are at risk of having a stroke or temporary symptoms of a stroke, known as transient ischemic attack (TIA). These posterior-circulation strokes account for 30% to 40% of all ischemic strokes, or approximately 200,000 cases per year, in the U.S.
The risk of a repeat stroke associated with VBD may be tied to several factors, including the degree to which the blockage reduces the blood flow to the brain, Hanjani says. Patients with VBD can have blockages ranging from partial to complete, which affect blood flow accordingly. Some patients with VBD can also have normal blood flow to the back of the brain.
The trial set out to identify patients with VBD and low blood flow to see whether they had a higher risk of recurrent stroke than had those with normal blood flow to the back of the brain. Of the enrolled patients, 25% were identified as having low posterior blood flow.
“We found that patients with low blood flow had a 22% risk of recurrent stroke in the first 12 months versus a 4% risk for patients whose blood flow was not low,” Hanjani said. At 24 months, the risk for patients with low blood flow was up to 30% compared with 13% for other patients.
“The ultimate goal is to find what treatments might be most effective for each patient,” Hanjani said. “If you can establish that there is a proportion of people who have reduced blood flow, then you can consider them for treatments that might actually increase it –– for example, surgery or stents or other procedures that might open up the blood vessels,” she said.
“Just as importantly, if you find a group of people whose blood flow is not reduced,” Hanjani said, there would be no need to subject them to a procedure and its associated risks.
NOVA technology, a computer-based system used to visualize brain anatomy and to quantify blood flow developed at UIC, made it possible to identify patients with reduced posterior blood flow using standard MRI.
Adult stroke patients were assessed for low posterior blood flow and were followed for 1 to 2 years (average follow-up period: 22 months). All of the patients continued under the care of their neurologists and received standard care for their condition.
Source: EurekAlert; February 12, 2015.