High-risk Plaques Common in Asymptomatic Carotid Stenosis

By Will Boggs, MD

August 17, 2020

NEW YORK (Reuters Health) - High-risk plaques are present in about one in four patients with asymptomatic carotid stenosis and are associated with an increased incidence of cerebrovascular events, according to a new meta-analysis.

"Our results mean that some patients with asymptomatic carotid stenosis have higher risk of stroke than others and may benefit from more aggressive interventions that are yet to be fully defined," Dr. Joseph Kamtchum-Tatuene of the University of Alberta, in Edmonton, Canada, told Reuters Health by email.

Current international guidelines recommend considering revascularization for severe asymptomatic carotid stenosis, but this recommendation is increasingly controversial.

Results from several studies suggest that extending the assessment of the features of carotid plaque beyond the degree of stenosis could improve the selection of patients who have an increased risk of stroke and would benefit from revascularization.

Dr. Kamtchum-Tatuene and colleagues used data from 68 studies enrolling more than 21,000 participants to estimate the prevalence of plaques with high-risk features and the annual incidence of ipsilateral ischemic cerebrovascular events in patients with asymptomatic carotid stenosis.

The pooled prevalence of high-risk plaques was 26.5% among these participants. The most common high-risk features were neovascularization (43.4%), echolucency (42.3%), and lipid-rich necrotic core (36.3%).

The prevalence of high-risk plaques was not associated with demographic characteristics, grade of stenosis, or circumstances of enrollment (i.e., setting and planned endarterectomy).

By comparison, the odds of a high-risk plaque were 3.4-fold higher among patients with symptomatic carotid stenosis.

During a mean follow-up of 2.8 years, the incidence of ipsilateral ischemic events was significantly higher in patients with high-risk features (4.3 events per 100 person-years) than in those without high-risk features (1.2 events per 100 person-years), the researchers report in JAMA Neurology.

Compared with patients without high-risk features, patients with high-risk features had twice the odds of suffering ischemic stroke and 2.4-fold increased odds of transient ischemic attack.

In the subgroup of studies focusing on participants with severe stenosis only, the incidence of ipsilateral ischemic cerebrovascular events was also significantly higher in patients with high-risk features (7.3 events per 100 person-years) than in patients without high-risk features (1.7 events per 100 person-years).

"Our findings mean that it is possible to use the imaging techniques currently available to select patients with a higher risk of stroke and adjust their treatment and follow-up plans accordingly," Dr. Kamtchum-Tatuene said. "In patients with one or more of these high-risk features, medical therapy should be optimized, and surgery should be discussed on a case-by-case basis, ideally in multidisciplinary meetings whenever possible."

"We still need to conduct clinical trial to decide what the best approach is for our patients," he said. "Therefore, we encourage our colleagues to actively enroll patients in ongoing clinical trials."

Dr. Rodolfo Pini of the University of Bologna, in Italy, who recently reviewed outcomes of asymptomatic severe carotid stenosis in the era of best medical therapy, told Reuters Health by email, "Many recent experiences reported an annual incidence of stroke ipsilateral to a carotid artery stenosis around 1%, in particular if associated with best medical therapy (good pressure control, antiplatelet, and statin). Many physicians suggest treating patients with asymptomatic carotid stenosis only with best medical therapy (BMT) and consider carotid endarterectomy (CEA) only in very selected patients."

"Therefore, the annual cerebral ischemic event of 3% is similar to the data reported from the ACST trial, of 20 years ago, that support the benefit of CEA plus BMT compared with BMT alone," said Dr. Pini, who was not involved in the new analysis.

"However, despite the good methodology of the paper and the interesting findings, I think that the debate will still continue," he noted, adding that the low rate of antiplatelet-drug use and the fact that not all studies were recent might make the results somewhat less relevant.

SOURCE: https://bit.ly/31wpSsW JAMA Neurology, online August 3, 2020.