Evaluating Stent Placement Benefits for Extracranial Vertebral Artery Stenosis

Background Stent placement is a treatment option 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 ≤ 30 days of the qualifying event of ischemic stroke from two randomized controlled trials evaluating stent placement versus 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 two‐years post‐randomization follow‐up using Kaplan Meier curves. Results Ninety‐four patients (50 randomized to stent placement and 44 to best medical treatment only) were included in the analysis. 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 lower in patients randomized to stent placement after adjustment for age and use of antihypertensive medication at baseline. The estimated proportion of patients with vertebrobasilar arterial distribution ischemic stroke free survival at two years post‐randomization was higher in subjects randomized to stent placement (92% versus 80.9%, log‐rank p‐value=0.06). Conclusions Patients with EVAS can potentially benefit from stent placement ≤ 30 days of an ischemic stroke and should be further evaluated in clinical trials.