22 Dec Hemodynamic Imaging Helps Predict Stroke Risk in Posterior Circulation Stroke
MedicalResearch.com Interview with:
Sepideh Amin-Hanjani, MD FAANS FACS FAHA
Professor & Program Director
Co-Director, Neurovascular Surgery
Department of Neurosurgery
University of Illinois at Chicago
Past Chair, AANS/CNS Cerebrovascular Section
Medical Research: What is the background for this study? What are the main findings?
Dr. Amin-Hanjani: Posterior circulation strokes account for up to 30% of all ischemic strokes, and atherosclerotic occlusive disease of the vertebrobasilar (VB) is responsible for approximately one third of these cases. Symptomatic atherosclerotic VB occlusive disease is associated with a high risk of recurrent stroke despite medical therapy, in the range of 10-15% within 2 years. There have been advances in treatment options, particularly endovascular angioplasty and stenting, aimed at reverting the blockage; however these procedures themselves carry risks, and are likely to benefit only selected patients who are at highest risk without intervention. Our study, VERiTAS, aimed to determine if measurement of blood flow in the posterior circulation vessels could identify the high risk patients. Flow measurements were performed using the technique of quantitative magnetic resonance angiography (QMRA) relying on standard MR sequences and the commercial software NOVA. These flow measurements were used to designate patients presenting with symptomatic vertebrobasilar disease as flow compromised or not, and patients were then followed for a median of 23 months in a blinded fashion to determine the risk of subsequent strokes. We found that among 72 such patients, only one quarter (18 patients) demonstrated flow compromise on QMRA, but that this group had a significantly higher risk of subsequent stroke at one year, 22% vs only 4% in the other group. The hazard ratio for subsequent stroke was markedly elevated at 11.5 even after adjusting for age and other stroke risk factors.
Medical Research: What should clinicians and patients take away from your report?
Dr. Amin-Hanjani: Clinicians and patients should know that assessment of the hemodynamic effect of vertebrobasilar occlusive disease is feasible and easily performed using a noninvasive imaging modality, the quantitative MRA (QMRA NOVA) technique which provides measurement of blood flow in cerebral vessels. Furthermore, these measurements provide a method for risk stratification for subsequent stroke in patients with symptomatic vertebrobasilar disease; this has important implications for patient management including identification of high risk patients for potential interventions, but also identification of low risk patients who would be unsuitable for potentially risky procedures.
Medical Research: What recommendations do you have for future research as a result of this study?
R Dr. Amin-Hanjani: The VERiTAS study has established a robust imaging biomarker for future stroke risk in verebrobasilar disease. This information can be used in future research looking at interventions aimed at restoring blood flow, such as endovascular angioplasty, by identifying the suitable high risk subgroup of flow compromised patients who are most likely to benefit from the treatment.
Amin-Hanjani S, Pandey DK, Rose-Finnell L, et al. Effect of Hemodynamics on Stroke Risk in Symptomatic Atherosclerotic Vertebrobasilar Occlusive Disease. JAMA Neurol. Published online December 21, 2015. doi:10.1001/jamaneurol.2015.3772.
Sepideh Amin-Hanjani, MD FAANS FACS FAHA (2015). Hemodynamic Imaging Helps Predict Stroke Risk in Posterior Circulation Strokes