Real-world effectiveness of thrombectomy for basilar artery occlusion: lessons beyond the ATTENTION and BAOCHE trials

Abstract Background The ATTENTION (0–12 hours) and BAOCHE (6–24 hours) trials demonstrated the efficacy of endovascular treatment (EVT) for basilar artery occlusion (BAO) in highly selected populations, but real-world generalizability remains uncertain. Patients and methods We analyzed patients with acute BAO presenting within 24 hours of last known well from a nationwide, multicenter, prospective stroke registry. Patients were categorised as ATTENTION-eligible, BAOCHE-eligible, and ineligible based on clinical and neuroimaging criteria from both trials. The primary outcome was the distribution of 3-month modified Rankin Scale (mRS). Secondary outcomes included 3-month mRS of 0–3 and 0–2, 90-day mortality, and symptomatic hemorrhagic transformation. Inverse probability of treatment weighting was applied to adjust for baseline differences. Results Among 49,471 patients with acute ischemic stroke, 2.0% (n = 1012) had BAO. Of these, 24% met ATTENTION-criteria, 6% met BAOCHE-criteria, and 72% were ineligible for both. Endovascular treatment was performed in 75%, 59%, and 43% of these groups, respectively. In ATTENTION-eligible patients, EVT was associated with more favourable mRS distribution (cOR, 1.73; 95% CI, 1.03–2.93) and lower 3-month mortality (RR, 0.52; 95% CI, 0.33–0.80). In BAOCHE-eligible patients, adjusted models did not reach statistical significance due to limited sample size. Among ineligible patients, EVT was associated with lower mortality (RR, 0.77; 95% CI, 0.60–0.99). Symptomatic haemorrhage rates did not differ across groups. Conclusion Most BAO patients were ineligible for pivotal EVT trials, and eligibility for the more stringent BAOCHE criteria was particularly rare in real-world practice. Endovascular treatment was associated with reduced mortality even in ineligible patients. These findings highlight the practical limitations of current trial-based selection criteria and support broader application of EVT for BAO.