Carotid Calcium Volume and Stenosis after Stent Implantation

Internal carotid artery (ICA) stenosis could be treated with stent placement. It was hypothesized that calcium amount could be predictive of vessel stenosis after stent placement. We utilised computed tomography (CT) angiography to quantify volume of calcium material in bulbar ICA.

28 patients with 31 treated ICA stenosis were collected and analysed using CT angiography-based calcium volume measurement. The Casper stent system (CSS) was used exclusively. Prospective data on emergent carotid stenosis were collected using serial ultrasound controls over a 12-month period.

Median age was 76 years (interquartile range (IQR) 67.5-77.8) and the majority were men (71.4%). Plaque median calcium volume was 0.142 cm3 (IQR 0.030 - 0.227) and median average Hounsfield Units (HU) were 561.0 (414.5-675.0). We detected positive linear relationship between average HU and ICA calcium volume. Furthermore, weak positive correlation was observed between calcium volume and residual stenosis as seen on post-interventional angiography, (correlation coefficient R = 0.38, p=0.035). Stronger positive correlation emerged between plaques' average HU and residual stenosis (R = 0.42, p=0.018). Angiographic stenosis showed univariate association with late stenosis as detected 12 months after CAS.

Calcium burden could be associated with residual stenosis after CSS placement. Larger studies are needed to confirm our preliminary data.