Symptomatic ≤50% carotid artery stenosis is associated with higher rates of vulnerable plaque features and acceptable revascularization outcomes: A three-stroke-center cohort study.

OBJECTIVE: Current carotid revascularization paradigms are primarily stenosis-based, with optimized medical therapy alone generally recommended for symptomatic patients with (≤50%) mild-to-moderate degree of stenosis (MMDS) and no routine recommendation for revascularization, despite evidence of potentially high-risk plaque features beyond stenosis. We aimed to contrast clinical presentation, prevalence of vulnerable plaque features, and postrevascularization outcomes among symptomatic patients with MMDS and high-degree stenosis (HDS > 50%) across three stroke centers.

METHODS: We performed a retrospective multicenter case-control study of symptomatic patients with MMDS vs HDS who underwent carotid revascularization from January 2016 to February 2026. Carotid revascularization procedures included were endarterectomy, transfemoral stenting, and transcarotid revascularization. MMDS was defined as ≤50% stenosis on all available preoperative cross-sectional imaging using North American Symptomatic Carotid Endarterectomy Trial criteria and the European Society for Vascular Surgery 2023 Clinical Practice Guidelines. Patients with any imaging study showing >50% stenosis were classified as HDS. Baseline characteristics, symptom phenotype, preoperative medications, imaging findings, vulnerable plaque features on magnetic resonance angiography with vessel wall imaging, and 30-day and long-term outcomes were compared. Composite outcomes included ipsilateral stroke, transient ischemic attack, myocardial infarction, and death.

RESULTS: Among 800 symptomatic patients, 87 (10.9%) had MMDS and 713 (89.1%) had HDS. Patients with MMDS were more frequently male (MMDS: 85.1% vs HDS: 68.0%; P < .01) and more commonly presented with cerebral infarction (MMDS: 59.8% vs HDS: 48.4%; P = .04), whereas transient ischemic attack were trending more frequently in patients with HDS (MMDS: 23.0% vs HDS: 33.5%; P = .05). Neurologic severity was similar by the National Institutes of Health Stroke Scale at admission (MMDS: 3.00 ± 3.54 vs HDS: 4.34 ± 5.78; P = .27), National Institutes of Health Stroke Scale at discharge (MMDS: 1.60 ± 2.20 vs HDS: 2.02 ± 3.64; P = .80), modified Rankin Scale at discharge (MMDS: 0.87 ± 1.25 vs HDS: 0.81 ± 1.09; P = .43), and Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes score (MMDS: 3.83 ± 1.53 vs HDS: 3.47 ± 1.43; P = .31). Patients with MMDS had higher rates of intraplaque hemorrhage (MMDS: 64.0% vs HDS: 29.4%; P < .01), ulceration (MMDS: 30.0% vs HDS: 13.0%; P < .01), and overall vulnerable plaque features other than stenosis (MMDS: 80.0% vs HDS: 39.4%; P < .01). Thirty-day composite outcomes were similar (MMDS: 5.7% vs HDS: 3.7%; P = .39), as were long-term (3.3 ± 2.6 years) composite outcomes (MMDS: 17.2% vs HDS: 25.0%; P = .11). In a sensitivity analysis excluding patients with 50% stenosis, the <50% stenosis subgroup (n = 44) demonstrated findings consistent with the primary analysis, presenting significantly more commonly in males [MDS: 84.1% vs moderate-to-high degree stenosis (MHDS): 69.0%; P = .03], with higher rate of cerebral infarction as their presenting symptom (MDS: 65.9% vs MHDS: 48.7%; P = .03), and vulnerable plaque features (MDS: 84.6% vs MHDS: 42.3%; P <.01), without differences in 30-day or long-term outcomes.

CONCLUSIONS: In our series of consecutive revascularized patients with symptomatic carotid disease, compared with HDS, MMDS were more likely to present with cerebral infarction, and had a higher prevalence of vulnerable plaque features on cross-sectional imaging despite lower luminal vessel stenosis. There were similar 30-day and long-term postrevascularization outcomes. In symptomatic patients with MMDS, magnetic resonance angiography with vessel wall imaging plaque characterization may represent an important diagnostic step in the evaluation of patients with higher risk for recurrence of a subsequent neurovascular event. Prospective studies are needed to determine whether vulnerable plaque features, rather than vessel stenosis alone, should guide risk stratification and treatment selection in this population.