Plaque morphology in acute symptomatic intracranial atherosclerotic disease

Abstract

BackgroundIntracranial atherosclerotic disease (ICAD) is globally a major ischaemic stroke subtype with high recurrence. Understanding the morphology of symptomatic ICAD plaques, largely unknown by far, may help identify vulnerable lesions prone to relapse.MethodsWe prospectively recruited patients with acute ischaemic stroke or transient ischaemic attack attributed to high-grade ICAD (60%–99% stenosis). Plaque morphological parameters were assessed in three-dimensional rotational angiography, including surface contour, luminal stenosis, plaque length/thickness, upstream shoulder angulation, axial/longitudinal plaque distribution and presence of adjoining branch atheromatous disease (BAD). We compared morphological features of smooth, irregular and ulcerative plaques and correlated them with cerebral ischaemic lesion load downstream in MRI.ResultsAmong 180 recruited patients (median age=60 years; 63.3% male; median stenosis=75%), plaque contour was smooth (51 (28.3%)), irregular (101 (56.1%)) or ulcerative (28 (15.6%)). Surface ulcers were mostly at proximal (46.4%) and middle one-third (35.7%) of the lesions. Most (84.4%) plaques were eccentric, and half had their maximum thickness over the distal end. Ulcerative lesions were thicker (medians 1.6 vs 1.3 mm; p=0.003), had steeper upstream shoulder angulation (56.2° vs 31.0°; p<0.001) and more adjoining BAD (83.3% vs 57.0%; p=0.033) than non-ulcerative plaques. Ulcerative plaques were significantly associated with coexisting acute and chronic infarcts downstream (35.7% vs 12.5%; adjusted OR 4.29, 95% CI 1.65 to 11.14, p=0.003). Sensitivity analyses in patients with anterior-circulation ICAD lesions showed similar results in the associations between the plaque types and infarct load.ConclusionsUlcerative intracranial atherosclerotic plaques were associated with vulnerable morphological features and had a higher cumulative infarct load downstream.

Intracranial Arterial Calcification and Intracranial Atherosclerosis: Close but Different

“…Similar findings were found in intracranial arteries. Most of the progressive ICAD presented eccentric plaques (84.4%) ( 22 ), which was much more prevalent than other kinds of vasculopathy ( 23 ). However, discrepancies exist.…”

Association of Plaque Morphology With Stroke Mechanism in Patients With Symptomatic Posterior Circulation ICAD

“… 22 , 23 However, with the recent advances in neuroimaging technology, some factors have been both verified and shown to be at least equally (if not more) effective in the evaluation of ischemic stroke than the older methods. 24 , 25 The vessel wall imaging using HRMRI is sensitive enough to enable the delineation of vessel wall changes caused by intracranial atherosclerosis or other etiology, such as vasculitis or dissection. For stroke patients with intracranial atherosclerosis, adding a group of measurable morphological features (e.g., plaque burden, plaque length, lesion eccentricity, and remodeling ratio) to the time-tested lumen stenosis identification may improve clinician's ability to detect the presence of ICAD in the posterior circulation, categorize symptomatic plaque, and quantitatively assess the degree of stroke risk and/or recovery potential.…”

Risk stratification in symptomatic intracranial atherosclerotic disease with conventional vascular risk factors and cerebral haemodynamics

“…These are technical limitations of CFD modelling in ICAS that need to be improved in future studies. Last but not least, there are other factors that may affect stroke risk in sICAS, such as positive/negative remodeling32 and the plaque characteristics (plaque ulceration, morphology and components) 33 34. These all need to be separately or simultaneously considered in future studies developing risk prediction tools in sICAS.…”