Highly-calcific carotid lesions endovascular management in symptomatic and increased-stroke-risk asymptomatic patients using the CGuard™ dual-layer carotid stent system: Analysis from the PARADIGM study

Objectives To assess feasibility, safety, angiographic, and clinical outcome of highly-calcific carotid stenosis (HCCS) endovascular management using CGuard (TM) dual-layer carotid stents. Background HCCS has been a challenge to carotid artery stenting (CAS) using conventional stents. CGuard combines a high-radial-force open-cell frame conformability with MicroNet sealing properties. Methods The PARADIGM study is prospectively assessing routine CGuard use in all-comer carotid revascularization patients; the focus of the present analysis is HCCS versus non-HCCS lesions. Angiographic HCCS (core laboratory evaluation) required calcific segment length to lesion length >= 2/3, minimal calcification thickness >= 3 mm, circularity (>= 3 quadrants), and calcification severity grade >= 3 (carotid calcification severity scoring system [CCSS]; G0-G4). Results One hundred and one consecutive patients (51-86 years, 54.4% symptomatic; 106 lesions) received CAS (16 HCCS and 90 non-HCCS); eight others (two HCCS) were treated surgically. CCSS evaluation was reproducible, with weighted kappa (95% CI) of 0.73 (0.58-0.88) and 0.83 (0.71-0.94) for inter- and intra-observer reproducibility respectively. HCCS postdilatation pressures were higher than those in non-HCCS; 22 (20-24) versus 20 (18-24) atm, p = .028; median (Q1-Q3). Angiography-optimized HCCS-CAS was feasible and free of contrast extravasation or clinical complications. Overall residual diameter stenosis was single-digit but it was higher in HCCS; 9 (4-17) versus 3 (1-7) %, p = .002. At 30 days and 12 months HCCS in-stent velocities were normal and there were no adverse clinical events. Conclusion CGuard HCCS endovascular management was feasible and safe. A novel algorithm to grade carotid artery calcification severity was reproducible and applicable in clinical study setting. Larger HCCS series and longer-term follow-up are warranted.