Authors: Alice Weatherston
Research due to be presented next week at the annual meeting of the Radiological Society of North America will suggest that individuals with diabetes may be harboring advanced vascular disease that could increase their risk of stroke. The team of researchers highlight the use of 3-D magnetic resonance imaging (MRI) for arterial imaging as a potential method for identifying stroke risk in diabetics.
Despite narrowing of the carotid arteries being strongly associated with the risk of stroke, little is known about stroke risk in individuals who do not present with these narrowed arteries.
“A recent analysis of multiple studies has shown that people with carotid artery narrowing and intraplaque hemorrhage (IPH) have a five- to six-times higher risk of stroke in the near future compared to people without,” explained study author Tishan Maraj (Sunnybrook Research Institute & University of Toronto; ON, Canada).
The new study therefore searched for evidence of IPH as an indicator of advanced atherosclerotic disease, focusing on individuals with diabetes, a group already known to be at increased risk of stroke and with worse outcomes compared to the non-diabetic population.
Utilizing 3D MRI, data on the prevalence of carotid IPH was collected from 159 asymptomatic type 2 diabetic patients with an average age of 63 years. All were recruited from a previous dietary trial that took place between 2010 and 2013.
Results indicated that 37 patients (23.3%) within the trial had IPH in at least one carotid artery and five of these exhibited IPH in both carotid arteries. These cases of IPH discovered were linked to an increased carotid artery wall volume and were found in the absence of carotid artery stenosis or narrowing.
“It was surprising that so many diabetic patients had this feature,” comented Maraj. “We already knew that people with diabetes face three to five times the risk of stroke, so perhaps IPH is an early indicator of stroke risk that should be followed up.”
Maraj also believes that the use of 3D MRI as opposed to traditional 2D MRI in this study provided the additional power needed to identify IPH within the carotid arteries. “The advantage of 3D MRI is you can image the entire carotid artery and pinpoint the area of interest over a shorter period of time compared with multiple 2D sequences,” he proposed.
The study was not able to provide data on patient outcomes or whether these individuals went on to develop carotid artery blockages more quickly than those with no IPH present. However, given the well known role of blood as a destabilizing factor of plaque, eventually leading to rupture and potentially stroke, IPH is likely to have a role to play.
On the future uses of IPH analysis, Maraj concluded: “Even though you can’t treat IPH, you can monitor patients a lot more closely.”