Vulnerable carotid plaque characteristics on magnetic resonance vessel wall imaging: potential predictors for hemodynamic instability during carotid artery stenting

BACKGROUND: This cross-sectional study sought to explore the possible risk factors assessed with magnetic resonance (MR) vessel wall imaging for hemodynamic instability (HI) during carotid artery stenting (CAS). METHODS: Patients with carotid stenosis who were referred for CAS from January 2017 to December 2019 were recruited and underwent carotid MR vessel wall imaging. The vulnerable plaque features, including lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH), fibrous cap rupture, and plaque morphology, were evaluated. The HI was defined as a drop of systolic blood pressure (SBP) of ≥30 mmHg or the lowest SBP measurement of <90 mmHg after stent implantation. The carotid plaque characteristics were compared between the HI and non-HI groups. The association between carotid plaque characteristics and HI was analyzed. RESULTS: A total of 56 participants (mean age 68.7±8.3 years; 44 males) were recruited. Patients in the HI group (n=26, 46%) had a significantly greater wall area [median 43.2 (IQR, 34.9–50.5) vs. 35.9 (IQR, 32.3–39.4) mm(2); P=0.008], total vessel area (79.7±17.2 vs. 69.9±17.3 mm(2); P=0.03), prevalence of IPH (62% vs. 30%; P=0.02), prevalence of vulnerable plaque (77% vs. 43%; P=0.01), and volume of LRNC [median 344.7 (IQR, 155.1–665.7) vs. 103.1 (IQR, 53.9–162.9) mm(3); P=0.001] in carotid plaque compared to those in non-HI group (n=30, 54%). Carotid LRNC volume (OR =1.005, 95% CI: 1.001–1.009; P=0.01) and presence of vulnerable plaque (OR =4.038, 95% CI: 0.955–17.070; P=0.06) were significantly and marginally associated with HI, respectively. CONCLUSIONS: Carotid plaque burden and vulnerable plaque features, particularly a larger LRNC, might be effective predictors for HI during the CAS procedure.