Endovascular therapy significantly improved survival and functional outcomes for patients with acute vertebrobasilar artery occlusion stroke when performed within 24 hours of estimated onset, according to a comprehensive meta-analysis published in The Lancet.

The VERITAS study analyzed individual patient data from 988 participants across four major randomized trials (ATTENTION, BASICS, BAOCHE, and BEST), representing this treatment's largest analysis to date for posterior circulation strokes.

Results showed 45% of patients receiving endovascular therapy achieved favorable functional outcomes at 90 days versus 30% in the control group. The number needed to treat for one additional favorable outcome was six patients.

The therapy was associated with reduced mortality (36% vs 45%) despite increased rates of symptomatic intracranial hemorrhage (5% vs <1%).

"The magnitude of the treatment effect is similar to that of endovascular therapy for anterior circulation stroke due to large artery occlusion," wrote editorialists Jan K. Ho, MD, and Graeme J. Hankey, MD.

The study included predominantly male patients (69%) with a median age of 67 years. The median National Institutes of Health Stroke Scale score was 22, indicating moderate to severe strokes. More than 90% of patients were randomized within 12 hours of estimated stroke onset.

Of the 4 included trials, 3 were conducted in China, with Chinese patients comprising 70% of the total cohort. The authors noted this could affect generalizability, given higher rates of intracranial atherosclerotic disease in Asian populations.

The benefit remained uncertain for patients with mild symptoms (NIHSS <10) and those with extensive baseline infarcts. Additionally, the study found a substantial under-representation of female participants (31%).

Vertebrobasilar artery occlusion accounts for approximately 1% of all ischemic strokes but can lead to mortality rates exceeding 70-80% without intervention. The results suggested endovascular therapy could substantially improve outcomes for most patients when performed at experienced centers.

The findings may influence clinical practice guidelines regarding emergency management of posterior circulation strokes, though the authors emphasized careful patient selection remains important, particularly regarding stroke severity and extent of baseline infarction.

Further research will be needed to establish the therapy's role in patients with mild symptoms or extensive infarcts, as well as those presenting beyond 24 hours.