Symptomatic Nonstenotic Carotids: A Topical Review.

Area of Science:

• Vascular Neurology
• Cardiovascular Medicine
• Interventional Radiology

Background:

• Current carotid artery disease management prioritizes stenosis degree (≥50%) for stroke risk assessment and intervention.
• This approach may overlook vulnerable plaques in nonstenotic (<50%) arteries, contributing to cryptogenic strokes.
• Intraplaque hemorrhage and other plaque features offer superior prognostic value over stenosis alone.

Purpose of the Study:

• To review the historical context of carotid artery disease management.
• To integrate contemporary biomarkers of plaque vulnerability into a mechanistic understanding of thromboembolization.
• To discuss imaging tools, clinical studies, and targeted treatments for symptomatic nonstenotic carotid artery disease.

Main Methods:

• Historical review of carotid artery disease management guidelines.
• Analysis of contemporary biomarkers for plaque vulnerability (e.g., intraplaque hemorrhage, lipid-rich necrotic core, fibrous cap rupture).
• Review of imaging modalities for detecting vulnerable plaque features.
• Synthesis of recent clinical studies on symptomatic nonstenotic carotid disease and its management.

Main Results:

• Accumulating evidence highlights structural and biological plaque features as critical indicators of stroke risk.
• Symptomatic nonstenotic carotid plaques with high-risk features may underlie a subset of embolic strokes of undetermined source.
• Advanced imaging is revealing the prevalence and natural history of this underdiagnosed condition.

Conclusions:

• Reclassifying symptomatic nonstenotic carotid plaques with high-risk features is proposed.
• Targeted treatments for this subgroup could prevent recurrent cerebrovascular events.
• High-level evidence is needed to align clinical practice with contemporary understanding of plaque instability.