Intracranial carotid artery calcification subtype and collaterals in patients undergoing endovascular thrombectomy

Sven P.R Luijten,Sophie C Van Der Donk,Kars C.J Compagne,Lonneke S.F Yo,Marieke E.S Sprengers,Charles B.L.M Majoie,Yvo B.W.E.M Roos,Wim H Van Zwam,Robert Van Oostenbrugge,Diederik W.J Dippel,Aad Van Der Lugt,Bob Roozenbeek,Daniel Bos

doi:10.1016/j.atherosclerosis.2021.10.005

Abstract

Background and aimsDistinct subtypes of intracranial carotid artery calcification (ICAC) have been found (i.e., medial and intimal), which may differentially be associated with the formation of collaterals. We investigated the association of ICAC subtype with collateral status in patients undergoing endovascular thrombectomy (EVT) for ischemic stroke. We further investigated whether ICAC subtype modified the association between collateral status and functional outcome. MethodsWe used data from 2701 patients with ischemic stroke undergoing EVT. Presence and subtype of ICAC were assessed on baseline non-contrast CT. Collateral status was assessed on baseline CT angiography using a visual scale from 0 (absent) to 3 (good). We investigated the association of ICAC subtype with collateral status using ordinal and binary logistic regression. Next, we assessed whether ICAC subtype modified the association between collateral status and functional outcome (modified Rankin Scale, 0–6). ResultsCompared to patients without ICAC, we found no association of intimal or medial ICAC with collateral status (ordinal variable). When collateral grades were dichotomized (3 versus 0–2), we found that intimal ICAC was significantly associated with good collaterals in comparison to patients without ICAC (aOR, 1.41 [95%CI:1.06–1.89]) or with medial ICAC (aOR, 1.50 [95%CI:1.14–1.97]). The association between higher collateral grade and better functional outcome was significantly modified by ICAC subtype (p for interaction = 0.01). ConclusionsPatients with intimal ICAC are more likely to have good collaterals and benefit more from an extensive collateral circulation in terms of functional outcome after EVT.

Highlights

Distinct subtypes of intracranial carotid artery calcification (ICAC) have recently been found to exist, namely ICAC located predominately in the medial layer of the artery and ICAC located predominately in the intimal layer of the artery [1,2]
Compared to patients without ICAC, we found no association of intimal nor medial ICAC with collateral status (Table 2)
Among patients with ICAC, there was a statistically nonsignificant tendency towards better collateral status in patients with intimal ICAC compared to those with a medial ICAC

Summary

Introduction

Distinct subtypes of intracranial carotid artery calcification (ICAC) have recently been found to exist, namely ICAC located predominately in the medial layer of the artery and ICAC located predominately in the intimal layer of the artery [1,2]. A medial calcification subtype was found to affect the internal elastic lamina, without atherosclerotic changes to the artery [1,2] Against this background, it is conceivable that these different ICAC subtypes exert a differential effect on the formation and development of collateral vessels. Distinct subtypes of intracranial carotid artery calcification (ICAC) have been found (i.e., medial and intimal), which may differentially be associated with the formation of collaterals. We investigated the association of ICAC subtype with collateral status in patients undergoing endovascular thrombectomy (EVT) for ischemic stroke. We further investigated whether ICAC subtype modified the association between collateral status and functional outcome. We assessed whether ICAC subtype modified the association between collateral status and functional outcome (modified Rankin Scale, 0–6).

Methods

Results

Discussion

Conclusion