Carotid plaque echolucency increases the risk of stroke in carotid stenting: The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) study

Abstract

Conclusion: Increased echolucency of carotid artery plaques increases the risk of stroke associated with carotid artery angioplasty and stenting (CAS). Summary: This is a report of 418 cases of CAS derived from the the Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) Registry and collected from 11 international centers. The authors used high-resolution B-mode duplex scanners in conjunction with a computer-assisted index of echogenicity (gray scale median [GSM]) to quantify carotid plaque echolucency. GSMs were classified as <25 or >25. Neurologic deficits during CAS and in the postprocedural period were recorded. Overall, the rate of neurologic complications was 3.6% (major stroke, 1.4%; minor stroke, 2.2%). Eleven strokes occurred in patients whose carotid plaque GSMs were <25 (n = 155, 7.1%), and 4 strokes occurred in patients with GSMs > 25 (n = 263, 1.5%, P = .005). Patients with >85% carotid stenosis had a higher rate of stroke (P = .03). Cerebral protection devices appeared effective in patients with GSMs > 25 (P = .01) but did not appear effective in those with GSMs ≤ 25. Multivariable analysis indicated that GSM (odds ratio [OR], 7.11; P = .002) and severity of stenosis (OR, 5.76; P = .010) were independent predictors of stroke. Comment: The data suggest that patients with more echolucent plaques and with higher degrees of internal carotid artery stenosis are at higher risk of neurologic complications with carotid artery stenting. The embolic potential of soft (echolucent) plaques is obvious to all who have visualized such plaques at the time of carotid endarterectomy. The authors also suggest the higher neurologic complication rate in patients with more severe stenosis may reflect a higher number of embolic particles associated with crossing a tight lesion with an endovascular device.