Effect of stenting on the near-infrared spectroscopy-derived lipid core burden index of carotid artery plaque

Thin Calcification Predicts Lipid Component in Carotid Plaque-Relationship Between Lipid Distribution and Thin Calcification

BACKGROUND

Accurately evaluating plaque characteristics is essential because lesions with lipid-rich plaque put patients at risk of thromboembolic complications from carotid artery stenting. Near-infrared spectroscopy (NIRS) is a diagnostic imaging modality that identifies lipid components from the near-infrared absorption pattern but does not reveal the distribution of calcification. The purpose of this study was to investigate the calcification characteristics of unstable carotid plaques, focusing on relationships between the calcification characteristics revealed by computed tomography angiography and the lipid core distribution derived from NIRS.

METHODS

Participants in this retrospective analysis comprised 35 patients (29 men, 6 women; mean age, 76.0 years; range, 52-89 years) who underwent carotid artery stenting in our institute between January 2021 and December 2022. We evaluated the thickness and length of carotid calcifications at the minimal lumen level from preoperative computed tomography angiography and analyzed the relationship with maximum lipid core burden index (max-LCBI) from NIRS.

RESULTS

Strong negative linear correlations were observed between the thickness of calcification and max-LCBI at Area (any segment in a target lesion) (r = -0.795, P < 0.001), max-LCBI at minimal lumen area (r = -0.795, P < 0.001) and lipid core burden index (LCBI) at lesion (rate of LCBI in entire plaque lesion) (r = -0.788, P < 0.001), respectively. Significant negative linear correlations were observed between distribution of calcification length and max-LCBI at area (r = -0.429, P = 0.01), max-LCBI at minimal lumen area (r = -0.373, P = 0.027), and LCBI at lesion (r = -0.443, P = 0.008).

CONCLUSIONS

Thin and ubiquitous carotid calcification was associated with LCBI values derived from NIRS indicative of carotid lipid plaque distribution, implying the possibility of predicting lesion instability.

Dual-layered stents reduce cerebral embolism compared with first-generation stents during carotid stenting of high lipid core plaque lesions

BACKGROUND

Periprocedural lipid core plaque (LCP) has been detected in carotid arteries assessed by catheter-based near-infrared spectroscopy (NIRS). High LCP is associated with cerebral embolism after carotid artery stenting (CAS) using a first-generation stent. We aimed to evaluate whether dual-layered stents reduce embolic infarcts in patients with high LCP and change of lipid signal as assessed by NIRS during CAS.

METHODS

Participants comprised 210 consecutive patients undergoing CAS. The study was divided into two distinct periods, with first-generation closed-cell stents used in the earlier period and dual-layered stents used in the later period. NIRS was performed at baseline, after stent implantation, and after balloon post-dilatation to analyze maximal lipid core burden index at minimal luminal area (max-LCBIMLA).

RESULTS

The ipsilateral cerebral embolism rate was significantly lower with dual-layered stents (9%) than with first-generation stents (33%, p<0.001), particularly with highly lipidic lesions (12% vs 60%, p<0.001). On multivariate logistic regression analysis, high LCP and first-generation stent usage were factors related to ipsilateral cerebral embolism (both p<0.001; OR 8.28 (95% CI 3.49 to 19.64) and OR 8.07 (95% CI 2.33 to 27.93), respectively). Max-LCBIMLA decreased significantly after stenting in both groups (both p<0.01) and max-LCBIMLA after balloon post-dilatation was significantly lower with dual-layered stents (22.4±65.6) than with first-generation stents (124.2±208.2; p=0.006).

CONCLUSIONS

Dual-layered stents reduce embolic infarcts in patients with highly lipidic plaque lesions as assessed by NIRS who undergo CAS. Dual-layered stents significantly reduced NIRS-derived lipid signals after stenting.

Comparison of 30-Day Outcomes after Carotid Artery Stenting in Patients with Near-Occlusion and Severe Stenosis: A Propensity Score Matching Analysis

BACKGROUND AND PURPOSE

Carotid artery near-occlusion is a type of severe stenosis with complete or partial distal luminal collapse and intracranial collaterals. This study aimed to compare 30-day outcomes and 10-year survival in patients undergoing carotid artery stenting for near-occlusion with a control group of patients with severe stenosis.

MATERIALS AND METHODS

We used data from a registry of 639 patients who underwent 789 carotid artery stenting procedures between 2005 and 2021. The primary end point was any stroke or death within 30 days after carotid artery stenting. Patients were matched using propensity scores based on 6 variables.

RESULTS

Propensity score matching yielded 84 subjects in the near-occlusion group matched with 168 subjects in the control group. In the matched cohort, the primary end point occurred in 7 (8.3%) and 11 (6.6%) patients in the near-occlusion and control groups, respectively (P = .611). In the unmatched cohort, the primary end point occurred in 7 (8.3%) and 19 (4.1%) patients (P = .101). Survival in the near-occlusion group versus the control group in the matched cohort at 5 and 10 years was 69.8% (95% CI, 58.0%-78.8%) versus 77.3% (95% CI, 70.0%-83.1%) and 53.3% (95% CI, 39.9%-65.0%) versus 53.3% (95% CI, 44.5%-61.4%) (log-rank, P = .798).

CONCLUSIONS

Carotid stent placement in patients with ICA near-occlusion was not associated with an increased 30-day risk of stroke or death compared with severe stenosis. Survival up to 10 years after carotid artery stenting was similar in both groups.

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

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 mm3 (P<0.001) with mean stent expansion 43%±24%. The mean luminal volume increased from 717±302 to 760±359 mm3 (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.

Near-infrared spectroscopy carotid plaque characteristics and cerebral embolism in carotid artery stenting

BACKGROUND

Perioperative thromboembolism is the main consideration in carotid artery stenting (CAS). Precise evaluation of carotid plaque components is clinically important to reduce ischaemic complications since CAS mechanically pushes plaque outwards, which releases plaque debris into the bloodstream.

AIMS

This study aimed to determine whether high lipid core plaque (LCP) assessed by catheter-based near-infrared spectroscopy (NIRS) is associated with ipsilateral cerebral embolism by diffusion-weighted magnetic resonance imaging during CAS using a first-generation stent.

METHODS

Carotid stenosis magnetic resonance (MR) T1-weighted plaque signal intensity ratio (T1W-SIR) followed by NIRS assessment at the time of CAS (using the carotid artery Wallstent) was performed in 117 consecutive patients.

RESULTS

The maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA; max-LCBIMLA) and the max-LCBI for any 4 mm segment in a target lesion defined as max-LCBIarea were significantly higher for the post-procedural new ipsilateral diffusion-weighted magnetic resonance imaging (DWI)-positive than negative patients (p<0.001 for all). There was a significant linear correlation between max-LCBIarea and the number of new emboli (r=0.544, p<0.0001). We also found that the second quantile (Q2) of T1W-SIRMLA had a significantly higher max-LCBIMLA and a higher incidence of DWI positivity than Q1 and Q3 (p<0.001 for all). Furthermore, max-LCBIMLA appeared to distinguish between patients with and without postoperative new ipsilateral DWI positivity (AUC 0.91, 95% CI: 0.86-0.96; p<0.0001).

CONCLUSIONS

High LCP assessed by NIRS is associated with cerebral embolism by diffusion-weighted imaging in CAS using a first-generation stent.

Long-term survival of carotid stenting patients with regard to single- or double-vessel carotid artery disease: a propensity score matching analysis

INTRODUCTION

There is lack of long-term data outside of controlled clinical trials in carotid artery stenting (CAS). In this study, we compared the short-term outcome, long-term survival, and rate of re-interventions for restenosis in patients after CAS, related to the extent of carotid atherosclerosis classified as single-vessel (unilateral) or double-vessel (bilateral) carotid artery disease.

MATERIAL AND METHODS

We retrospectively evaluated 599 patients with significant carotid artery stenosis, who underwent 763 CAS procedures, and used the propensity score to match 226 pairs (452 patients) in the single- or double-vessel carotid disease.

RESULTS

There was no significant difference in the occurrence of in-hospital major adverse events (3.5% vs. 3.1% of patients in the double-vessel carotid group vs. the single-vessel carotid group; p = 1) The mean follow-up was 6.1 ±4.0 years, and a total of 181 (40%) deaths occurred during 2759 patient-years, which translates into 7.8 and 5.3 deaths per 100 patient-years in the double-vessel carotid group and the single-vessel carotid group, respectively (p < 0.01). The survival in the double-vessel carotid group vs. the single-vessel carotid group at 10 years was 46% (95% CI: 38-54%) vs. 55% (95% CI: 47-63%) (p < 0.01). Twenty-four (11%) patients and 6 (3%) patients underwent re-interventions for restenosis in the double-vessel and the single-vessel carotid disease group, respectively (p < 0.01).

CONCLUSIONS

Patients with CAS and significant double-vessel carotid artery disease had similar peri-procedural risk, but had a worse long-term survival, and a higher rate of re-interventions for restenosis compared to the single-vessel carotid artery disease patients.

Carotid artery plaque composition and distribution: near-infrared spectroscopy and intravascular ultrasound analysis

Most atherosclerotic plaques (APs) form in typical predilection areas of low endothelial shear stress (ESS). On the contrary, previous data hinted that plaques rupture in their proximal parts where accelerated blood flow causes high ESS. It was postulated that high ESS plays an important role in the latter stages of AP formation and in its destabilization. Here, we used near-infrared spectroscopy (NIRS) to analyse the distribution of lipid core based on the presumed exposure to ESS. A total of 117 carotid arteries were evaluated using NIRS and intravascular ultrasound (IVUS) prior to carotid artery stenting. The point of minimal luminal area (MLA) was determined using IVUS. A stepwise analysis of the presence of lipid core was then performed using NIRS. The lipid core presence was quantified as the lipid core burden index (LCBI) within 2 mm wide segments both proximally and distally to the MLA. The analysed vessel was then divided into three 20 mm long thirds (proximal, middle, and distal) for further analysis. The maximal value of LCBI (231.9 ± 245.7) was noted in the segment localized just 2 mm proximally to MLA. The mean LCBI in the middle third was significantly higher than both the proximal (121.4 ± 185.6 vs. 47.0 ± 96.5, P < 0.01) and distal regions (121.4 ± 185.6 vs. 32.4 ± 89.6, P < 0.01). Lipid core was more common in the proximal region when compared with the distal region (mean LCBI 47.0 ± 96.5 vs. 32.4 ± 89.6, P < 0.01).