News | Stroke | December 23, 2015

Low Blood Flow in Back of Brain Increases Recurrent Stroke Risk

Advanced MRI analysis identifies patient group at high risk of stroke recurrence who would most benefit from angioplasty

recurrent stroke risk, low blood flow, vertebrobasilar region, NOVA, UIC

December 23, 2015 — Patients who have had a stroke in the back of the brain are at greater risk of having another within two years if blood flow to the region is diminished, according to results of a multicenter study led by researchers at the University of Illinois at Chicago (UIC). These stroke patients are the most likely to benefit from risky intervention to unblock arteries, and they can be identified using a new magnetic resonance imaging (MRI)-based technology developed at UIC. The findings are published in the journal JAMA Neurology.

The vertebrobasilar region in the back of the brain is responsible for locomotion and balance. Vertebrobasilar strokes can be devastating, causing partial or total paralysis. They account for 30 percent to 40 percent of all strokes, or about 200,000 cases per year in the United States.

Stroke patients found to have narrowing of the blood vessels in the back of the brain caused by atherosclerosis can have angioplasty, a procedure to open blocked arteries, but the procedure carries its own risks. And because blockages don’t always correlate to locally reduced blood flow – thought to be the real culprit in raising stroke risk – researchers wanted to better understand the relationship between arterial blockages, blood flow and recurrent strokes.

“Having a blockage present in a blood vessel doesn’t always correlate to low blood flow,” said Sepideh Amin-Hanjani, M.D., professor of neurological surgery at the UIC College of Medicine and principal investigator on the study. “There can be a blockage and flow can be normal, if other nearby blood vessels are able to compensate.”

She and her colleagues wanted to try to identify which stroke patients are at highest risk for further strokes and so might benefit from angioplasty despite the risks of the procedure.

They followed 72 adult patients who had a stroke or temporary symptoms of a stroke, known as a transient ischemic attack, in the back of the brain and who also had at least 50 percent blockage of the arteries in that part of the brain. The patients were followed for an average of 22 months at five academic medical centers as they continued receiving standard care for their condition from their neurologists.

Participants were evaluated for reduced blood flow in the back of the brain using NOVA, or Noninvasive Optimal Vessel Analysis, a software program that can quantify the volume, velocity and direction of blood flowing through any major vessel in the brain using standard MRI equipment. The NOVA software was developed at UIC by Fady Charbel, M.D., professor and head of neurological surgery, who is a co-author of the new study.

One-fourth of the study participants were found to have diminished blood flow in the back of the brain, which turned out to be a significant predictor of subsequent stroke. These patients had 12- and 24-month stroke-free survival rates of 78 percent and 70 percent, respectively, compared to 96 percent and 87 percent for patients with normal blood flow.

“At one year, the risk for patients with low blood flow was about five times as high as risk for patients without low flow in the back of the brain,” Hanjani said. For these patients, the benefits of angioplasty probably outweigh the risks.

“About three-quarters of patients didn’t have low blood flow in the vertebrobasilar region – other arteries are doing the job of ensuring that proper blood flow is reaching that area – and these patients would not benefit from treatments aimed at opening the vessels, such as angioplasty – in fact, the procedure would put these patients at unnecessary risk,” Hanjani said.

The ultimate goal is to find what treatments might be most effective for each patient, Hanjani said.

The UIC Office of Technology Management helped to transfer the NOVA technology to a startup. VasSol Inc. further developed the technology into a product with an improved user interface, adding functionality and applicability.

Hanjani and her colleagues hope that the ease of identifying the high-risk group using NOVA will enable further study of the condition and the evaluation of new therapies to further reduce the risk of recurrent stroke.

The study sites that enrolled patients were UIC; Washington University of St. Louis; the University of California, Los Angeles; Columbia University in New York; and the University of Toronto/Toronto Western Hospital.

The study was funded by the National Institutes of Health/National Institute of Neurological Disorders and Stroke. Additional funding was provided by the Dr. Ralph and Marian Falk Research Trust Foundation. Material research support was provided by VasSol Inc.

For more information: www.chicago.medicine.uic.edu

Related Content

Corindus Announces First Patient Enrolled in PRECISION GRX Registry
News | Robotic Systems| September 18, 2017
September 18, 2017 — Corindus Vascular Robotics Inc.
Two-Year ILLUMENATE Trial Data Demonstrate Efficacy of Stellarex Drug-Coated Balloon
News | Drug-Eluting Balloons| September 18, 2017
Philips announced the two-year results from the ILLUMENATE European randomized clinical trial (EU RCT) demonstrating...
Sentinel Cerebral Protection System Significantly Reduces Stroke and Mortality in TAVR
News | Embolic Protection Devices| September 18, 2017
September 18, 2017 – Claret Medical announced publication of a new study in the...
Marijuana Associated With Three-Fold Risk of Death From Hypertension
News | Hypertension| September 14, 2017
Marijuana use is associated with a three-fold risk of death from hypertension, according to research published recently...
Peter Schneider, M.D. presents late breaking clinical trial results at VIVA 17 in Las Vegas. Panelists (l to r) Krishna Rocha-Singh, M.D., Sean Lyden, M.D., John Kaufman, M.D., Donna Buckley, M.D.

Peter Schneider, M.D. presents late breaking clinical trial results at VIVA 17 in Las Vegas. Panelists (l to r) Krishna Rocha-Singh, M.D., Sean Lyden, M.D., John Kaufman, M.D., Donna Buckley, M.D.

Feature | Cath Lab| September 14, 2017
September 14, 2017 — Here are quick summaries for all the key late-breaking vascular and endovascular clinical trials
Medtronic Announces Japanese Regulatory Approval for In.Pact Admiral Drug-Coated Balloon
News | Drug-Eluting Balloons| September 13, 2017
Medtronic plc announced that the In.Pact Admiral Drug-Coated Balloon (DCB) received approval from the Japanese Ministry...
PQ Bypass Reports Positive Results for Detour System in Patients With Long Femoropopliteal Blockages
News | Peripheral Artery Disease (PAD)| September 13, 2017
A subset analysis of the DETOUR I clinical trial showed promising safety and effectiveness results of PQ Bypass’ Detour...
News | Cardiac Diagnostics| September 12, 2017
Contracting shingles, a reactivation of the chickenpox virus, increases a person’s risk of stroke and heart attack,...
Vascular screening for abdominal aortic aneurysm, peripheral artery disease and hypertension during the VIVA Study in Denmark

Vascular screening for abdominal aortic aneurysm, peripheral artery disease and hypertension during the VIVA Study. Photo credit: Lisbeth Hasager Justesen, Viborg Hospital.

News | Cardiac Diagnostics| September 12, 2017
September 12, 2017 — A new screening program for vascular disease saves one life for every 169 men assessed, accordin
News | Pharmaceuticals| September 12, 2017
September 12, 2017 — Inclisiran lowers low-density lipoprotein (LDL, or “bad”) cholesterol for up to one year in pati
Overlay Init