High-Resolution MRI-Based Clinical–Radiological Phenotypes of Carotid Vulnerability and Long-Term Outcomes After Carotid Revascularization: A Single-Center Retrospective Cohort Study

Background/Objectives: Patients undergoing carotid revascularization may show distinct patterns of bilateral carotid vulnerability and clinical risk. This study used latent class analysis (LCA) to identify high-resolution magnetic resonance imaging (HR-MRI)-based clinical–radiological phenotypes and evaluate their association with long-term major adverse cardiovascular events (MACE). Methods: This retrospective cohort included 289 patients who underwent carotid endarterectomy (CEA) or carotid artery stenting (CAS) between April 2017 and April 2024 and had preoperative carotid HR-MRI within 90 days. Ipsilateral and contralateral plaque features were assessed on multi-contrast vessel-wall HR-MRI. LCA included five indicators: ipsilateral intraplaque hemorrhage, ipsilateral lipid-rich necrotic core, contralateral intraplaque hemorrhage, cardiovascular disease history, and symptomatic status. MACE comprised cardiovascular death, nonfatal myocardial infarction, coronary revascularization, or stroke. Outcomes were assessed using Kaplan–Meier analysis and multivariable Cox regression. Results: Among 289 patients undergoing carotid revascularization, the mean age was 65.12 ± 9.46 years, and 237 (82.0%) patients were men. LCA identified three phenotypes: Systemic High-Risk (n = 128), Silent High-Risk (n = 37), and Stable/Moderate (n = 124). The Systemic High-Risk phenotype showed high probabilities of symptomatic presentation, cardiovascular disease history, and bilateral carotid vulnerability, whereas the Silent High-Risk phenotype showed marked ipsilateral plaque vulnerability despite lower clinical risk. During a median follow-up of 4.4 years, MACE-free survival differed significantly across phenotypes (log-rank p = 0.043). Compared with the Stable/Moderate phenotype, the Systemic High-Risk and Silent High-Risk phenotypes were both associated with increased MACE risk (HR 1.65, 95% CI 1.15–2.37, p = 0.039; HR 1.43, 95% CI 1.12–2.15, p = 0.034). Conclusions: HR-MRI-based LCA identified clinically meaningful carotid vulnerability phenotypes associated with long-term MACE after carotid revascularization. These findings support integrated assessment of bilateral plaque vulnerability and clinical risk for postoperative cardiovascular risk stratification.