Inflammatory Mediators and Cerebral Embolism in Carotid Stenting: New Markers of Risk

Abstract

To investigate serological predictors of risk for cerebral embolism after carotid artery stenting (CAS). Twenty consecutive symptomatic and asymptomatic patients (13 men; mean age 74 years) with carotid artery stenosis undergoing standardized filter-protected CAS (Wallstent) were preoperatively evaluated to identify unstable plaque (duplex ultrasound), complicated aortic plaque (transesophageal echocardiography), and inflammatory status [high-sensitivity C-reactive protein (hs-CRP) and serum amyloid-A protein (SAA) serum levels]. Aortic arch type, carotid tortuosity, and complexity of the procedure were considered. Cerebral embolism was evaluated by comparing the number, volume, and side (ipsilateral and non-ipsilateral) of preoperative and postoperative cerebral lesions detected on diffusion-weighted resonance magnetic imaging (DW-MRI) and through light and scanning electron microscopy analysis of cerebral protection filters obtained from CAS. All CAS procedures were completed with no complications. All patients had a negative preoperative DW-MRI, but at least 1 asymptomatic cerebral lesion appeared on DW-MRI after the procedure in 18 (90%) patients. Female gender was associated with a higher number of cerebral lesions (18.2±10.9 vs. 8.3±8.8 for men, p=0.03). Carotid plaque morphology, supra-aortic vessel anatomy, and procedure complexity did not correlate with number or volume of new cerebral lesions. Complicated aortic plaque was associated with a higher volume of non-ipsilateral cerebral lesions than uncomplicated plaque (235.0±259.3 vs. 63.6±63.2 mm(3), respectively; p=0.02). Hs-CRP ≥5 mg/L and SAA ≥10 mg/L were significantly associated with a higher number of new cerebral lesions [16.2±10.7 vs. 4.3±3.4 for hs-CRP <5 mg/L (p=0.02) and 14.8±10.3 vs. 2.8±3.4 for SAA <10 mg/L (p=0.006), respectively]. Hs-CRP ≥5 mg/L and SAA ≥10 mg/L also correlated with greater surface involvement by embolic materials in the protection filters at microscopic analysis [37.0% (5.1%) vs. 26.9% (2.5%) for hs-CRP <5 mg/L, p=0.004; 35.9% (13.5%) vs. 22.2% (6.9%) for SAA <10 mg/L, p=0.02]. In addition to female gender and the presence of complicated aortic plaque, inflammatory status can be a predictor of cerebral embolism in CAS.