Stenting vs. medical treatment in patients with symptomatic vertebral artery stenosis: a randomized open-label phase 2 trial
The VAST trial randomized patients suffering a minor stroke or transient ischemic attack due to >50% vertebral artery stenosis to medical therapy versus vertebral artery stenting. It enrolled 115 patients and was halted prematurely due to insufficient funding. The primary combined outcome measure of recurrent stroke, myocardial infarction or death was statistically equivalent across both treatment groups. The trial’s early termination unfortunately limits statistical power, with non-inferiority an unsurprising result. Other severe limitations include: The interventional arm was open label, and included both intracranial and extracranial lesions. These anatomic targets carry dramatically different risk profiles and endovascular techniques. Moreover, consideration was not given to patients’ collateral circulation adequacy and need for revascularization.
Overall, the VAST trial fails to establish a benefit to vertebral artery stenting, but carries lessons in its design that may inform future studies for optimal patient selection, uniformity of devices and anatomic location.