Association between occlusion site and clinical outcomes in patients with acute basilar artery occlusion

PURPOSE: This study aimed to analyze the association between different occlusion sites and clinical outcomes in acute basilar artery occlusion (ABAO) patients. PATIENTS AND METHODS: This study recruited ABAO patients from the BASILAR registry to evaluate outcomes by occlusion sites (distal, middle and proximal ABAO) and treatment modality. Primary effectiveness outcome was assessed by the modified Rankin Scale (mRS) score 0-3 and secondary effectiveness outcomes were mRS 0-2 and 0-1. Safety outcomes included the mortality at 90 days and the occurrence of symptomatic intracranial hemorrhage (sICH) within 48 h. RESULTS: In endovascular treatment (EVT) group, after multivariable regression analysis, compared to distal occlusions, middle occlusions were significantly and negatively associated with clinical outcomes (mRS 0-3, adjusted odds ratio (aOR) 0.36, 95 % confidence interval (CI) 0.20-0.63, P < 0.001; mRS 0-2, aOR 0.51, 95 % CI 0.29-0.91, P = 0.023). However, mortality and sICH did not differ significantly between groups. Additionally, compared to standard medical therapy (SMT), patients following EVT significantly improved favorable outcomes (mRS 0-3) among 3 occlusion sites: distal (aOR 5.56, 95 % CI 1.74-17.79, P = 0.004), middle (aOR 5.06, 95 % CI 1.88-13.63, P = 0.001), and proximal (aOR 3.92, 95 % CI 0.94-24.05, P = 0.14). Similarly, the results of propensity score matching (PSM) were consistent with the above trends. CONCLUSION: In patients treated with EVT, our findings showed that clinical outcomes significantly differed by occlusion site. Additionally, EVT demonstrated superior clinical effectiveness among 3 occlusion sites compared to SMT. These findings support occlusion site-specific EVT prioritization in ABAO management. This study was registered with the Chinese Clinical Trial Registry (ChiCTR1800014759).