Imaging signs of vulnerability, neurological events and cognitive impairment in asymptomatic carotid artery stenosis: results from the Carotid Artery Multi-modality imaging Prognostic (CAMP) study

Abstract

Abstract Background Carotid artery plaques with imaging signs of vulnerability, such as ulceration, intraplaque haemorrhage (IPH) or a lipid-rich necrotic core (LRNC), are associated with a high risk of ischemic stroke, and are reported to be considered for invasive treatment if % diameter stenoses ≥60. Little is known about their fate in patients with <60% stenoses. Purpose To evaluate the prevalence of ulceration, IPH and LRNC and their characteristics in patients with asymptomatic, non-significant (<60%) carotid artery stenoses. Methods One hundred and twenty-one patients with asymptomatic, unilateral, mild/moderate (40-60%) carotid artery stenoses at Doppler ultrasound (DUS), were prospectively evaluated with computed tomography angiography (CTA), magnetic resonance angiography (MRA) and brain magnetic resonance imaging (MRI). IPH and LRNC were defined at MRA, while ulceration was defined at CTA. Verbal and memory skills were tested by the Fifteen Reye’s Words and other standardized tests. Results At least one sign of vulnerability (IPH, LRNC or ulceration) was detected in 51.6% patients. Signs of vulnerability were more frequent in patients with ≥50% stenoses compared with those with <50% at DUS (62.5% vs 27.6%, p=0.002). No difference in the prevalence of cardiovascular risk factors was present in those with and without signs of vulnerability (Table). An ulceration at CTA was significantly associated with presence of IPH or LRNC even after adjustment for the degree of stenosis (OR 4.2, 95% CI 1.3-13.2; OR 4.0, 95% CI 1.4-11.2). Subclinical embolic brain infarctions were found in 10% of patients. A higher prevalence of LRNC was found in patients with brain infarctions (50% vs 17%, p<0.05). Patients with either IPH or LRNC performed worse at standardized tests of cognitive impairment (score 1.6±1.1 vs 2.2±1.4, p<0.05). Conclusions Imaging signs of vulnerability are highly prevalent in patients with asymptomatic intermediate carotid artery stenosis, and can be detected in more than one fourth of patients with a non-significant plaque in terms of degree of stenosis. Plaque ulceration at CTA is independently associated with LRNC and IPH at MRA, independent of the degree of stenosis. Plaques with LRNC are associated with subclinical embolic brain infarcts and a worse cognitive performance.TableFigure