Abstract 42: CAS versus CEA Treatment Differences in Long-Term Outcomes and Post-Procedural Durability: the Carotid Stenosis Trialist Collaboration (CSTC)

Abstract

Introduction: A 3.4% (95% CI: 2.1% to 4.7%) higher peri-procedural stroke and death risk has been previously documented for those treated with carotid artery stenting (CAS) relative to those treated with carotid endarterectomy (CEA). However, the CAS versus CEA treatment differences in long-term outcomes and the post-procedure durability have not been described. Methods: Data from the 4 largest CAS-versus-CEA randomized trials for treatment of symptomatic carotid atherosclerosis (EVA-3S, SPACE, ICSS, and CREST) were pooled, and treatment differences assessed for the outcome of any stroke or death during a 120-day peri-procedural period, plus ipsilateral stroke afterward. Results: Long-term follow-up was analysed for 4754 patients. Median length of follow-up across the studies ranged from 2.0 to 6.9 years, with 88 peri-procedural and 55 post-procedural events among those CEA-treated, and 169 and 64 for those CAS-treated. After the peri-procedural period, the annual rates of stroke following CAS was 0.6% (95% CI: 0.5 to 0.8) and following CEA 0.6% (95% CI: 0.5 to 0.8), resulting in non-significant durability differences of less than 1% over the period extending up to 9 years (see Table). The previously-documented 3.4% higher peri-procedural event rate in the CAS group contributed to a significant 3.1% (95% CI: 1.6% to 4.7%) treatment difference at 1-year, and the aforementioned similar durability implied that this significant difference remained relatively constant over the period extending up to 9 years (see table). Conclusions: The post-procedure durability of CAS and CEA were similar, both with event rates below 1%. The similarity of post-procedure events rates implies that the previously-documented higher peri-procedural in the CAS group is “carried forward” with a higher risk of outcomes extending to 9-years.