Prevalence of ipsilateral “vulnerable carotid plaques with <50 % stenosis” on CT angiography in embolic stroke of undetermined source

Background

Carotid plaques may be an important etiology in ischemic stroke. We aimed to assess carotid plaque characteristics ipsilateral and contralateral to the ischemic stroke and assessed the prevalence of “vulnerable carotid plaques with <50% stenosis” based on different imaging-based definitions in patients with large vessel occlusion and source of embolic stroke of undetermined source (ESUS) on CT Angiography (CTA).

Methods

Data are from the ESCAPE-NA1 trial (Efficacy and safety of nerinetide for the treatment of acute ischemic stroke), a multicenter, randomized study that included anterior circulation large vessel occlusion patients undergoing thrombectomy. Various CTA features of plaque vulnerability were combined to define “vulnerable carotid plaques” in different ways. Within ESUS patients, prevalence of vulnerable plaques ipsilateral vs. contralateral to the intracranial occlusion was compared.

Results

We analyzed 132 patients whose ischemic stroke mechanism was determined to be ESUS. Plaques causing 30–50 % stenosis (as compared to no stenosis) and plaque surface irregularity were significantly more common in ipsilateral carotid arteries (37[28.0 %] vs. 18[13.6 %]; p < 0.001 and 102[77.3 %] vs. 78[59.1 %]; p = 0.002). The prevalence of ipsilateral “vulnerable carotid plaques” varied depending on imaging definition used for such plaques between 55 and 74 %, but irrespective of the definition used, the prevalence of “vulnerable carotid plaques” was consistently higher in ipsilateral carotid arteries compared to contralateral carotid arteries.

Conclusions

In ESUS patients undergoing thrombectomy for anterior circulation large vessel occlusion, vulnerable carotid plaques are more prevalent ipsilateral to the intracranial occlusion. Irregular plaque surface, and a higher degree of stenosis were the most common vulnerable plaque features.