IF02 - Impact Of Grade Of Stenosis On Early And Mid-Term Outcomes Of Carotid Artery Stenting

Objectives: to investigate the impact of grade of stenosis on early and mid-term outcomes of transfemoral carotid artery stenting (CAS), using different stent designs.

Methods: We conducted a single-center retrospective analysis of patients with asymptomatic carotid stenosis >70% undergoing CAS (2012- 2024). Grade of stenosis, plaque length, and Agatston calcification score were assessed on preoperative computed tomography angiogram. Grade of stenosis was classified as Very-high-grade (VHGS) if >85% by NASCET criteria, High-Grade (HGS) if 70-84%. Both dual-layer (DL) and old-generation (OG) open-cell or closed-cell stent designs were used. Endpoints were early (30-days) stroke and 2-years freedom from restenosis, defined by any occlusion, related reintervention, or restenosis >80% of the stented carotid artery.

Results: There were 437 CAS procedures, 54 (12%) with a VHGS and 383 (88%) with a HGS. Comparing VHGS vs HGS, lesion length (1.3±0.8 cm vs 1.4±0.9 cm; P=.399), Agatston score (149±124 vs 169±168; P=.110), and use of DL stent (52% vs 67%; P=.057) were similar. An embolic protection device was successfully used in all cases; VHGS more frequently received pre-dilatation before stent deployment (29% vs 1%; P<.001). Overall postoperative stroke occurred in 2.2% patients (0.5% major stroke rate). Stroke rate was 6% in VHGS and 0.5% in HGS (P=.001). After multiple logistic regression, grade of stenosis>85% (OR 4.44; 95%CI 1.80-9.40; P=.001) and plaque length>15 mm (OR 1.71; 95%CI 1.08-2.58; P=.025) were significantly associated with postoperative stroke. In the subset of VHGS, use of a DL stent (OR 0.05; 95%CI 0.02-0.99; P=.043) and predilatation (OR 0.09; 95%CI 0.06-0.92; P=.011) were protective from stroke. Two-years freedom from restenosis was 94±4% (VHGS:94±2%, HGS:95±2%; P=.532), with a 99±1% freedom ipsilateral stroke. Cox proportional hazards analysis showed that stent design (HR 1.63, 95%CI 0.36-15.44; P=.559) and grade of stenosis (HR 1.86, 95%CI 0.32-7.04; P=.228) were not associated with the risk of restenosis. VHGS with Agatston score >400 had a significantly increased risk of restenosis (HR 2.72, 95%CI 1.92-60.72; P=.014) regardless the type of stent used (HR 0.23, 95%CI 0.07-5.17; P=.364).

Conclusions: Stenting of carotid artery stenosis >85% carry a higher risk of postoperative stroke, especially in case of long plaques>15 mm. Predilatation and use of DL stents may mitigate this risk in case of VHGS. Grade of stenosis by itself was not associated with mid-term outcomes, but heavily calcified stenosis >85% had a higher risk for restenosis, regardless the type of stent used. These findings may help improving patient selection, operative technique, and follow-up protocol.