Stenting for symptomatic vertebral artery stenosis: The Vertebral Artery Ischaemia Stenting Trial

Abstract

Objective: To compare in the Vertebral Artery Ischaemia Stenting Trial (VIST) the risks and benefits of vertebral angioplasty and stenting with best medical treatment (BMT) alone for symptomatic vertebral artery stenosis.

Methods: VIST was a prospective, randomized, open-blinded endpoint clinical trial performed in 14 hospitals in the United Kingdom. Participants with symptomatic vertebral stenosis ≥50% were randomly assigned (1:1) to vertebral angioplasty/stenting plus BMT or to BMT alone with randomization stratified by site of stenosis (extracranial vs intracranial). Because of slow recruitment and cessation of funding, recruitment was stopped after 182 participants. Follow-up was a minimum of ≥1 year for each participant.

Results: Three patients did not contribute any follow-up data and were excluded, leaving 91 patients in the stent group and 88 in the medical group. Mean follow-up was 3.5 (interquartile range 2.1-4.7) years. Of 61 patients who were stented, stenosis was extracranial in 48 (78.7%) and intracranial in 13 (21.3%). No periprocedural complications occurred with extracranial stenting; 2 strokes occurred during intracranial stenting. The primary endpoint of fatal or nonfatal stroke occurred in 5 patients in the stent group vs 12 in the medical group (hazard ratio 0.40, 95% confidence interval 0.14-1.13, p = 0.08), with an absolute risk reduction of 25 strokes per 1,000 person-years. The hazard ratio for stroke or TIA was 0.50 (p = 0.05).

Conclusions: Stenting in extracranial stenosis appears safe with low complication rates. Large phase 3 trials are required to determine whether stenting reduces stroke risk.

Isrctncom identifier: ISRCTN95212240.

Classification of evidence: This study provides Class I evidence that for patients with symptomatic vertebral stenosis, angioplasty with stenting does not reduce the risk of stroke. However, the study lacked the precision to exclude a benefit from stenting.

Figure 1. Trial profile

*Intention-to-treat population.

Figure 2. Kaplan-Meier curves

Kaplan-Meier cures for the cumulative probability of (A) fatal or nonfatal stroke in any arterial territory (primary endpoint), (B) fatal or nonfatal stroke in any arterial territory or TIA, and (C) death resulting from any cause during follow-up, according to treatment group (intention-to-treat population). Log-rank test was used to test the hypothesis that stroke incidence, stroke or TIA incidence, or mortality rate between groups was the same.