Abstract DP140: Importance of Intracranial Atherosclerotic Disease in Patients with Extracranial Internal Carotid Artery Stenosis Undergoing Treatment

Background: Concurrent intracranial atherosclerotic disease (IAD) may adversely affect outcomes after carotid revascularization. We assessed the effect of IAD on outcomes in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST). Methods: CREST randomized symptomatic or asymptomatic patients with extracranial internal carotid artery (ICA) stenosis to carotid artery stenting (CAS) or carotid endarterectomy (CEA). The primary endpoint was any stroke, myocardial infarction (MI), or death during the periprocedural period, plus ipsilateral stroke within 4 years. For this analysis, IAD was defined as ipsilateral intracranial stenosis identified on baseline angiographic review (where available). The CREST protocol excluded patients with intracranial stenosis greater in severity than the extracranial target lesion; thus, IAD represented mild–moderate disease. Multivariable Cox models adjusted for age, sex, symptomatic status, treatment type, and extracranial ICA stenosis severity (moderate <70% vs severe ≥70%). Results: Of 2,020 patients with evaluable intracranial imaging, 196 (9.7%) had IAD. Over 4 years, the primary endpoint occurred more often with IAD than without (10.2% vs 6.7%; adjusted hazard ratio HR 1.50, 95% confidence interval CI 1.00–2.26). Ipsilateral stroke occurred more frequently in patients with IAD (7.6% vs 4.5%; adjusted HR 1.73, 95% CI 1.06–2.83). There was no independent difference in periprocedural rates of stroke, MI, or death attributable to IAD (interaction p=0.78), and patterns mirrored the parent trial (higher periprocedural stroke with CAS, higher MI with CEA). Conclusions: In CREST, mild–moderate ipsilateral IAD was associated with increased long-term risk of ipsilateral stroke and the composite endpoint after carotid revascularization, independent of procedure type. Incorporating intracranial imaging into pre-procedural evaluation may improve long-term risk stratification in patients considered for CEA or CAS.