Objective: To report the results of clinical follow-up at one year among patients in the BASILAR registry, a prospective registry that consecutively enrolled stroke patients with acute basilar artery occlusion from 47 comprehensive stroke centers in China between January 2014 and May 2019.

Methods: Patients in the BASILAR study received either conventional treatment or endovascular treatment. We assessed clinical outcomes in patients one year after enrolment into the BASILAR registry. The primary outcome was the modified Rankin scale score at one year, assessed as a common odds ratio using ordinal logistic regression shift analysis adjusted for pre-specified prognostic factors. Secondary outcomes included the modified Rankin scale-based outcome group at one year (0 to 1 [excellent outcome], 0 to 2 [good outcome], or 0 to 3 [favorable outcome]) and death from any cause.

Results: Of the 829 patients enrolled in the original BASILAR study, one-year data were available for 785 patients (94.7%). The distribution of outcomes on the modified Rankin scale favored endovascular treatment over conventional treatment (adjusted common odds ratio, 4.50; 95% confidence interval, 2.81 to 7.29; P < 0.001). The cumulative one-year mortality rate was 54.6% in the endovascular treatment group versus 83.5% in the conventional treatment group (adjusted hazard ratio, 4.36; 95% confidence interval, 2.69 to 7.29; P < 0.001).

Conclusions: The beneficial effect of endovascular treatment on functional outcome at one year in patients with acute basilar artery occlusion is similar to that reported at 90 days in the original study.

Clinical trial identifiers Numbers: ChiCTR-180001475