Extracranial vertebral artery stenosis patients that may benefit from stent placement: post-hoc analysis from randomized controlled trials

Background Stent placement is a treatment option intended to reduce the risk of ischemic events in patients with extracranial vertebral artery stenosis (EVAS). However, the patient subgroups that can potentially benefit from stent placement are not well defined. Methods We performed an exploratory pooled analysis of patients with EVAS (≥50% in severity) enrolled within 30 days of the qualifying event of ischemic stroke from two randomized controlled trials evaluating stent placement and medical treatment alone. We compared the risk of vertebrobasilar arterial distribution ischemic stroke and/or death (and other endpoints) post-randomization between the two groups using adjusted Cox proportional hazards models and estimated the event-free survival during 2-year post-randomization follow-up using Kaplan–Meier curves. Results A total of 94 patients (50 randomized to stent placement and 44 assigned to best medical treatment only) were included in the analysis. After adjusting for age and use of antihypertensive medication at baseline, the risks of vertebrobasilar arterial distribution ischemic stroke and/or death (hazard ratio [HR]: 0.4, 95% confidence interval [CI]: 0.1–1.1, p = 0.08), any stroke (HR: 0.2, 95% CI: 0.1–0.8, p = 0.02), ischemic stroke (HR 0.1, 95% CI: 0.03, 0.6, p = 0.01), and any stroke and/or death (HR 0.3, 95% 0.1–0.9, p = 0.03) were found to be lower in patients who underwent stent placement. The estimated proportion of patients with vertebrobasilar arterial distribution ischemic stroke-free survival at 2-year post-randomization was higher in patients randomized to stent placement (92% vs. 80.9%, log-rank p -value = 0.06). Conclusion Patients with EVAS can potentially benefit from stent placement within 30 days following an ischemic stroke and should be further evaluated in clinical trials.