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

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.

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.

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.

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.