Meta-Analysis: Endovascular Therapy for Vertebrobasilar Occlusion Improves Functional Outcomes
19 Dec, 2024 | 22:56h | UTCBackground: Acute vertebrobasilar artery occlusion (VBAO) is associated with high mortality and severe neurological deficits. Previous randomized trials of endovascular therapy (EVT) for VBAO have shown inconsistent results, leaving uncertainty about its efficacy across different patient subgroups.
Objective: To determine whether EVT confers improved 90-day functional outcomes compared with standard medical therapy alone in patients with acute VBAO and to explore treatment effect heterogeneity in prespecified subgroups.
Methods: This individual patient data meta-analysis included all four major randomized controlled trials (ATTENTION, BAOCHE, BASICS, BEST) that enrolled patients with VBAO treated within 24 hours of estimated onset. Participants received either EVT or best medical therapy. The primary outcome was a favorable functional status at 90 days (modified Rankin Scale [mRS] score 0–3). Secondary outcomes included functional independence (mRS 0–2), distribution of mRS scores (shift analysis), symptomatic intracranial hemorrhage (sICH), and all-cause mortality at 90 days.
Results: Among 988 patients (556 EVT; 432 control), median age 67 years, EVT significantly increased the proportion achieving mRS 0–3 (45% vs 30%; adjusted odds ratio [aOR] 2.41, 95% CI 1.78–3.26) and mRS 0–2 (35% vs 21%; aOR 2.52, 95% CI 1.82–3.48). EVT improved the overall distribution of functional outcomes (aOR for mRS shift 2.09, 95% CI 1.61–2.71) and reduced 90-day mortality (36% vs 45%; aOR 0.60, 95% CI 0.45–0.80). Although sICH was more common with EVT (5% vs <1%; aOR 11.98, 95% CI 2.82–50.81), the net clinical benefit remained strongly in favor of EVT. Subgroup analyses showed broadly consistent benefit, though the advantage was uncertain for patients with mild baseline severity (NIHSS <10).
Conclusions: EVT for acute VBAO significantly improves functional outcomes and reduces mortality despite a higher sICH risk. These results support EVT as a standard consideration in appropriately selected patients with moderate-to-severe VBAO. The benefit’s magnitude is comparable to that seen in anterior circulation large vessel occlusions, although caution is advised in mild cases and those with extensive baseline infarction.
Implications for Practice: Clinicians should consider EVT for most patients presenting with acute VBAO. While sICH risk is increased, the substantial improvements in function and survival justify its use in suitable candidates. Careful imaging and clinical assessment remain critical for optimal patient selection.
Study Strengths and Limitations: Strengths include a pooled individual patient dataset from all major VBAO EVT trials, allowing detailed subgroup analyses. Limitations involve early trial termination, underrepresentation of women, predominance of Asian populations, and exclusion of patients with very mild symptoms or large baseline infarcts, potentially limiting generalizability.
Future Research: Further trials are needed to define EVT’s role in patients with mild symptoms, isolated vertebral occlusion, large infarcts, or those presenting beyond 24 hours. Additional studies should assess real-world applicability and diverse patient populations.