Association of tirofiban with outcomes in acute basilar artery occlusion: an etiology-stratified post hoc analysis of the ATTENTION trial.

Abstract

Acute basilar artery occlusion (BAO) is a lethal neurovascular emergency where endovascular treatment (EVT) is limited by futile reperfusion. Tirofiban's adjunctive use in BAO yields inconsistent findings, likely due to unaddressed etiological heterogeneity-relevant in Asian populations with high atherosclerotic (AS) prevalence but substantial non-AS subgroups. This pre-specified post hoc ATTENTION trial analysis explored potential etiology-specific associations between tirofiban and BAO-EVT outcomes. We included 221 patients with BAO who underwent EVT in the ATTENTION trial (NCT04751708). Stroke etiology was categorized into AS and non-AS subgroups per the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria. Inverse probability of treatment weighting (IPTW) balanced baseline covariates (standardized mean difference <0.2), with doubly robust estimation to mitigate bias. Primary outcome was 90-day favorable function (modified Rankin Scale (mRS) 0-3). Safety outcomes included intracranial hemorrhage, symptomatic intracranial hemorrhage (sICH) at 24-72 hours, and 90-day mortality. Multivariate logistic regression analyzed outcomes, with pre-specified subgroup and likelihood ratio tests to explore tirofiban-etiology interactions. Overall, tirofiban was not associated with favorable outcomes, mortality, or sICH. A potential interaction between tirofiban and etiology was observed for primary outcome (P=0.006). In non-AS BAO, tirofiban was associated with potentially improved reperfusion (97.1% vs 92.5%, P=0.016), higher favorable outcomes (adjusted OR (aOR) 2.06, 95% CI 1.21 to 3.54, P=0.009), and reduced mortality (P=0.036), with no increased bleeding risk. In AS BAO, no benefits were observed, and tirofiban was associated with increased futile reperfusion (P=0.043; P=0.012 for stroke etiology×tirofiban interaction). Tirofiban may be associated with favorable outcomes in non-AS BAO without increasing hemorrhagic risk, whereas it confers no clear benefit and may elevate futile reperfusion in AS BAO. These findings support the concept of etiology-specific adjunctive therapy in BAO and underscore the need for prospective investigations of tirofiban in non-AS BAO populations.