Stenting for symptomatic vertebral artery stenosis: a preplanned pooled individual patient data analysis.

Abstract

Background: Symptomatic vertebral artery stenosis is associated with a high risk of recurrent stroke, with higher risks for intracranial than for extracranial stenosis. Vertebral artery stenosis can be treated with stenting with good technical results, but whether it results in improved outcome is uncertain. We performed an individual patient pooled analysis of completed randomised controlled trials comparing vertebral stenting with medical treatment for symptomatic vertebral stenosis.

Methods: We analysed individual participant data from 354 individuals from three trials, including 179 patients from VIST (148 extracranial, 31 intracranial), 115 patients from VAST (96 extracranial, 19 intracranial), and 60 intracranial patients from SAMMPRIS (no extracranial). The primary outcome was any fatal or nonfatal stroke. Cox regression analysis was performed stratified by trial.

Findings: 168 subjects (46 intracranial; 122 extracranial) were randomised to medical treatment and 186 to stenting (64 intracranial; 122 extracranial). In those randomised to stenting, the periprocedural stroke or death rate was higher for intracranial stenosis than for extracranial stenosis (10/64(15.6%) v 1/121(0.8%), p=0.00005). During 1,036 years of follow-up, the hazard ratio (HR) for any stroke in the stenting compared with the medical arm was 0.81 (95% confidence interval [CI] 0.45-1.44). For extracranial stenosis alone it was 0.63 (0.27-1.46), and for intracranial stenosis alone 1.06 (0.46-2.42). For patients randomised within 14 days of last symptoms HRs for any stroke were: all 0.65 (0.31-1.39), extracranial 0.56 (0.17-1.87), and intracranial 0.72 (0.27-1.90).

Interpretation: Stenting for vertebral stenosis has a much higher risk for intracranial, compared with extracranial, stenosis. This pooled analysis did not show a statistically significant benefit on preventing stroke for either treatment. There was no evidence of benefit of stenting for intracranial stenosis. Stenting for extracranial stenosis might be beneficial, but further larger trials are required to determine whether there is benefit in this subgroup.