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Positive Data Salvaged for Thrombectomy on Basilar Strokes

— BEST, BASICS trials not wholly negative, group finds

MedpageToday

Some patients with basilar artery occlusion strokes could benefit from endovascular therapy (EVT) after all, according to a closer look at the BEST and BASICS trials.

Among the pooled target population, the 351 stroke patients with baseline NIH Stroke Scale (NIHSS) scores of ≥10, EVT was associated with better odds of zero-to-moderate disability (modified Rankin Scale [mRS] 0-3) at 90 days compared with best medical management (38.7% vs 26.5%, adjusted OR 1.94, 95% CI 1.06-3.54) on adjusted intention-to-treat analysis.

Mortality rates numerically favored the EVT group over controls (40.3% vs 48.2%, adjusted OR 0.75, 95% CI 0.43-1.31) despite a jump in symptomatic intracranial hemorrhage (sICH; 5.0% vs 0.6%, adjusted OR 15.06, 95% CI 1.23-183.91), reported Raul Nogueira, MD, of Grady Memorial Hospital and Emory University School of Medicine in Atlanta, and colleagues in the VERITAS group, at the American Stroke Association virtual International Stroke Conference.

Subgroup analysis of the pooled patient-level data from BEST and BASICS suggested that older patients tended to have especially good outcomes with EVT.

Based on the study, it does appear "that some patients with basilar artery occlusion strokes benefit from mechanical thrombectomy," commented Steven Hetts, MD, of UCSF Mission Bay Hospitals in San Francisco.

"The trends do appear to be toward favoring EVT in selected patients, which is consistent with our earlier experience in anterior circulation large vessel occlusion [LVO] strokes," he noted.

Posterior circulation LVO strokes are hard to study given their rarity. These strokes are also characterized by complex symptoms and severity.

and both failed to show a benefit to EVT over medical management in vertebrobasilar occlusion strokes.

Nogueira noted that these two randomized trials had suffered from poor recruitment, crossovers, and selection issues, resulting in both being underpowered. Furthermore, the BASICS trial had undergone a protocol modification to allow recruitment of people with milder strokes (NIHSS <10), potentially diluting the treatment effect.

Indeed, a pooling of all 431 people in BEST and BASICS resulted in median baseline NIHSS dropping from 30 to 23.

In this larger population, there was no difference between groups achieving mRS 0-3 (43.6% vs 36.0%, adjusted OR 1.55, 95% CI 0.92-2.63) but a consistent increase in sICH after EVT (5.5% vs 0.5%, adjusted OR 19.16, 95% CI 1.72-212.95).

VERITAS investigators reported that the overall study cohort had a median age of about 68, and nearly a third of participants were women.

Importantly, underlying atrial fibrillation was more prevalent at baseline among the EVT arm compared with controls.

This implies "that their basilar occlusions may more likely have been from embolization of a clot from the heart to an otherwise normal basilar artery," according to Hetts. "I would expect that those patients would do better clinically than patients with underlying atherosclerotic disease in the basilar artery itself that leads to basilar artery occlusion."

There are three ongoing trials on EVT for basilar artery occlusion strokes in China, according to Nogueira.

  • author['full_name']

    Nicole Lou is a reporter for ľֱ, where she covers cardiology news and other developments in medicine.

Disclosures

Nogueira disclosed relevant relationships with Anaconda, Biogen, Cerenovus, Genentech, Imperative Care, Medtronic, Phenox, Prolong Pharmaceuticals, Stryker Neurovascular, Astrocyte, Brainomix, Cerebrotech, Ceretrieve, Corindus Vascular Robotics, Vesalio, Viz-AI, and Perfuze.

Primary Source

International Stroke Conference

Nogueira RG, et al "Vertebrobasilar occlusion randomization to endovascular reperfusion versus intravenous thrombolysis or medical treatment alone systematic evaluation (VERITAS) collaboration" ISC 2021; Abstract LB 11.