Real-World Outcomes of Carotid Artery Stenting in Symptomatic and Asymptomatic Patients With Carotid Artery Stenosis

Background The effectiveness and safety of carotid artery stenting (CAS) are comparable to those of carotid endarterectomy in both symptomatic and asymptomatic patients with carotid artery stenosis, but real-world outcomes are not well-known. Objectives The purpose of this study was to investigate the real-world clinical outcomes of CAS in symptomatic and asymptomatic patients with carotid artery stenosis. Methods We conducted a nationwide retrospective registry study of 156 centers between January 2015 and December 2019. We enrolled consecutive patients with CAS managed by certified specialists from the Japanese Society of Neuroendovascular Therapy. Outcomes between symptomatic and asymptomatic patients were compared. The primary outcome was a composite of ischemic stroke and all-cause death at 30 days after CAS. Secondary outcomes were ischemic stroke, all-cause death, intracranial hemorrhage (ICH), and procedural complications. Results We analyzed 9,792 patients (symptomatic, n = 5,351; asymptomatic, n = 4,441). The mean age was 73.5 years, and men were dominant (86.4%). Embolism protection devices were used in 99% of patients. The primary outcome was not significantly different between the symptomatic and asymptomatic groups (120 [2.2%] vs 65 [1.5%]; adjusted OR: 1.30; 95% CI: 0.92-1.83). The incidences of symptomatic ICH, any ICH, acute in-stent occlusion, and hyperperfusion syndrome were significantly more prevalent in the symptomatic group (47 [0.9%] vs 8 [0.2%], aOR: 4.41 [95% CI: 1.68-11.6]; 73 [1.4%] vs 12 [0.3%], aOR: 3.56 [95% CI: 1.71-7.39]; 45 [0.8%] vs 19 [0.4%], aOR: 2.18 [95% CI: 1.08-4.40]; and 102 [1.9%] vs 36 [0.8%], aOR: 1.78 [95% CI: 1.17-2.71], respectively). Other secondary outcomes were not significantly different between the 2 groups. Conclusions The complication rate after specialist-involved CAS at 30 days was low in real-world practice.