Long-term changes after carotid stenting assessed by intravascular ultrasound and near-infrared spectroscopy

Abstract

Background: Long-term effect of carotid stenting (CAS) on the stabilization of the plaque is almost unrecognized. Vascular healing and remodeling might seal the atherosclerotic plaque with neointimal hyperplasia decreasing the vulnerability. We aimed to assess long-term change in the lipid signal, stent and luminal dimensions and restenosis after CAS with the intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) imaging.Methods: We performed follow-up angiography and NIRS-IVUS imaging of 58 carotid stents in 52 patients. Median time from CAS to the follow-up examination was 31 months (range, 5-56). The lipid signal of the stented segment was calculated from a NIRS-derived chemogram (a spectroscopic map) as the lipid core burden index (LCBI, a dimensionless number from 0 to 1,000). Planimetric and volumetric measurements from IVUS were performed to assess change in minimal stent area (MSA), minimal luminal area (MLA), stent and luminal volume, late stent expansion and percentage in-stent restenosis (ISR) volume.Results: During the follow-up period, the mean (±SD) LCBI significantly decreased from 32±56 to 17±27 (P=0.002). The mean stent volume significantly increased from 717±302 to 1,019±429 mm 3 (P<0.001) with mean stent expansion 43%±24%. The mean luminal volume increased from 717±302 to 760±359 mm 3 (P=0.025) due to ISR encroaching 26%±15% of the stent volume.Conclusions: Lipid signal decreased during the follow-up period suggesting stabilization of the plaque.Late stent expansion was balanced with neointimal hyperplasia.Trial registration: The trial is registered under clinicaltrials.gov NCT03141580.

Imaging modality-dependent carotid stenosis severity variations against intravascular ultrasound as a reference: Carotid Artery intravasculaR Ultrasound Study (CARUS)

“…Despite accumulating evidence for the role of carotid plaque morphology in relation to the risk of carotid-related cerebral injury and stroke [ 1 – 10 ], current guidelines continue to recommend using stenosis severity thresholds (usually 50% and 70% in symptomatic patients and 60% and 80% in asymptomatic subjects) as the principal parameter in clinical decision-making that includes revascularization by surgical or endovascular route [ 2 , 3 , 11 – 13 ].…”

“…Despite growing understanding of the role of plaque morphology [ 1 – 10 ], stenosis severity remains the fundamental factor in clinical decision-making with regard to recommending medical or interventional therapy to symptomatic and asymptomatic patients with internal carotid artery (CA) atherosclerosis [ 2 , 3 , 11 – 13 ].…”