Aims: Perioperative thromboembolism is the main consideration in carotid artery stenting (CAS). 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 and results: Carotid stenosis magnetic resonance (MR) T1-weighted plaque signal intensity ratio (T1W-SIR) followed by NIRS assessment at the time of CAS (using Carotid Wallstent) was performed in 117 consecutive patients. The maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA; max-LCBIMLA) and 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.