The natural history of vertebral artery origin stenosis

We sought to determine the long-term survival and natural history of vertebral artery origin stenosis (VAOS) as it relates to stroke.

We retrospectively reviewed clinical data on patients admitted at a single institution for possible stroke between 2004 and 2007 and selected subjects who underwent angiography of the neck. We classified VAOS subjects as having "moderate" to "severe" (≥50%) occlusion. Age-, sex-, and race-matched control subjects with no evidence of VAOS on angiography were selected from our study population. Long-term follow-up data were collected and death certificates were searched for comparison among cases and controls. A Kaplan-Meier curve was plotted based on time to event (stroke or death).

Fifty-eight of the 358 subjects were found to have VAOS (16.2%). Four subjects were excluded because of stenting; therefore, 54 cases and 54 matched controls were included for long-term follow-up analysis. In our study population, we calculated that the relative risk of having a stroke or dying in patients with VAOS was 6 times that of patients without VAOS (P < .02). The observed 5-year survival rate for patients with VAOS was 67% (36/54) compared to 89% (48/54) in control subjects (P < .01).

Patients with VAOS are at a significantly higher risk of having a stroke or dying. Subsequent prospective, multicenter studies are needed to validate our results.