Intraplaque Hemorrhage and Plaque Ulceration Are More Likely in Patients with Symptomatic Mild-to-Moderate Carotid Artery Stenosis than in Symptomatic and Asymptomatic High-Grade Stenosis: A Retrospective Cohort Study

Objective: To compare a cohort of symptomatic patients with mild- to moderate (<70%) carotid artery stenosis with those patients with high-grade (≥70%) carotid artery stenosis (symptomatic and asymptomatic) to assess for markers that places them at a higher risk for stroke.

Methods: A propensity score matched cohort study design for all patients who underwent carotid revascularization between 2015 to 2024 was utilized to compare the high-grade (≥70%) symptomatic and asymptomatic carotid stenosis groups against the mild to moderate (<70%) symptomatic carotid stenosis group. Matched variables included age, sex, and atrial fibrillation. Vulnerable plaque was defined as the presence of intraplaque hemorrhage, ulceration, lipid necrotic core and inflammation on cross-sectional imaging. Images assessed included computed tomography angiography (CTA) and magnetic resonance angiography (MRA) with vessel wall imaging (VWI). Odds ratios (OR) were then calculated to assess for risk of vulnerable features present on cross-sectional imaging prior to carotid intervention.

Results: There were 58 patients in each cohort matched and analyzed. In our cohort of interest, there were fewer patients with diabetes and higher proportion of hyperlipidemia compared to those patients who were symptomatic with ≥70% carotid artery stenosis. Further, there were fewer patients with diabetes and none on dialysis compared to our asymptomatic high-grade stenosis group. The OR of presenting with vulnerable features in our mild- to moderate stenosis symptomatic group was 5.85 (95% CI 1.74-19.60, p=0.002) compared to the high-grade asymptomatic stenosis patients and 7.52 (95% CI 3.22-17.66, p<0.001) compared to the high-grade symptomatic stenosis patients. Additionally, the symptomatic <70% stenosis group had higher odds of intraplaque hemorrhage (OR 4.91, 95% CI 1.80-13.78, p<0.001) and ulcerated plaque (OR 8.93, 95% CI 2.47-32.82, p<0.001) compared to the asymptomatic ≥70% group, as well as increased odds of intraplaque hemorrhage (OR 4.14, 95% CI 1.59-10.74, p=0.002) and ulcerated plaque (OR 5.16, 95% CI 1.77-15.03, p=0.001) compared to the symptomatic ≥70% group. Composite outcomes of stroke, myocardial infarction and death were no different in 30-days and on mid-term follow-up.

Conclusion: High-risk plaque features on cross-sectional imaging studies may justify a short-term more aggressive medical management and/or early intervention in patients with mild to moderate carotid artery stenosis, even when luminal narrowing alone would not typically warrant such measures. As such, use of advanced imaging to assess for plaque characteristics may allow for improved risk stratification and guide earlier management of this patient population.