Marcia Frellick

November 30, 2015

CHICAGO — Using 3-dimensional MRI to assess the carotid arteries of patients with type 2 diabetes for intraplaque hemorrhage could help determine the risk for stroke, new research suggests.

Intraplaque hemorrhage — an indicator of advanced atherosclerotic disease — was found even in the absence of carotid artery stenosis, Tishan Maraj, MBBS, an imaging analyst at Sunnybrook Research Institute in Toronto, reported here at the Radiological Society of North America 2015 Annual Meeting

In their study, Dr Maraj and his colleagues focused on patients with diabetes because the risk for worse outcome after stroke and the risk for mortality are significantly higher in these patients than in those without diabetes.

Because patients with diabetes place a burden on the healthcare system, there is an urgency to preventing complications, he explained.

The 159 patients involved in the study were part of the Low Glycemic Index for Type 2 Diabetics trial being conducted by David Jenkins, MD, from St. Michael's Hospital in Toronto. Average age of the patients was 63 years.

Low Glycemic Index for Type 2 Diabetics Trial

Intraplaque hemorrhage was detected with 3D MRI in at least one carotid artery in 37 patients, and in five of these patients, it was detected in both arteries.

The investigators were surprised that the rate of intraplaque hemorrhage in at least one carotid artery was as high as 23%, Dr Maraj told Medscape Medical News.

The team then assessed vessel wall volume in patients with intraplaque hemorrhage in one artery, and were taken aback by the correlation. When they compared the two carotid arteries — the one with and the one without intraplaque hemorrhage — the difference in vessel wall volume was significantly different.

Despite the same exposure to factors such as blood sugar and blood pressure, intraplaque hemorrhage was contributing to the greater vessel wall volume.

"This suggested that, despite the same exposure to factors such as blood sugar and blood pressure, intraplaque hemorrhage was contributing to the greater vessel wall volume," Dr Maraj said.

There are no treatments for intraplaque hemorrhage, but therapies such as statins are known to improve vascular health and have been shown to decrease vessel wall thickness.

Because of this association, patients with intraplaque hemorrhage are at increased risk for advanced vascular disease. Therefore, "they should perhaps undergo more intensive monitoring and potentially more intensive standard therapy," Dr Maraj said. "Intervention at this stage of disease may stop the disease progressing."

However, he pointed out, it is too early to recommend that patients with diabetes undergo routine screening for intraplaque hemorrhage.

"Further follow-up of these patients is needed to see if intraplaque hemorrhage at this early stage will lead to accelerated vascular disease resulting in vessel narrowing and/or clinical events," he explained.

3D MRI promises to improve our ability to predict future stroke in patients with carotid atherosclerosis, said Jin-Moo Lee, MD, PhD, from the Stroke and Cerebrovascular Center at Barnes-Jewish Hospital and the Washington University School of Medicine in St. Louis, Missouri.

"For the past 25 years, the only means to stratify stroke risk in patients with carotid artery atherosclerosis was to measure the degree of narrowing in that artery. This new technique adds another characteristic that may help stratify risk by examining bleeding within the plaque," he told Medscape Medical News.

The high proportion of patients with diabetes who had intraplaque hemorrhage could take our understanding of diabetes and stroke risk to another level, he said. But he agrees with Dr Maraj that more studies are necessary.

"It is known that patients with diabetes and narrowing of the carotid arteries have a higher risk of stroke than patients without diabetes," Dr Lee explained. "However, what remains to be seen is whether intraplaque hemorrhage will improve our ability to predict future stroke in diabetic or other populations. That will undoubtedly be one of the next studies that will be performed."

Dr Maraj and Dr Lee have disclosed no relevant financial relationships.

Radiological Society of North America (RSNA) 2015 Annual Meeting: Abstract SSA17-05. Presented November 29, 2015.


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