Computed Tomography Perfusion Parameters: A Potential Tool for Treatment Selection in Basilar Artery Occlusion.

Objective: This study aimed to evaluate the association between computed tomography perfusion (CTP) parameters and outcomes in basilar artery occlusion (BAO), and to select patients with BAO who may benefit from thrombectomy.

Methods: We performed a post-hoc analysis of patients from the ATTENTION trial with available admission CTP data. CTP parameters evaluated included time to maximum (T) >6 s/8 s/10 s, relative cerebral blood flow (rCBF) <20%/30%/34%/38%/50%, Critical Area Perfusion Score (CAPS), and CTP-posterior circulation acute stroke prognosis early computed tomography score (CTP-pc-ASPECTS), pons-midbrain-thalamus (PMT) hypoperfusion. Multivariable Firth logistic regression was used to analyze associations between CTP parameters and outcomes and to explore treatment interactions. The primary outcome was favorable outcome, defined as modified Rankin Scale score of 0-3, at 90 days.

Results: The study included 109 patients (70 thrombectomy, 39 control). Multivariable analysis showed that lower CAPS, smaller rCBF <34% volume, and higher CTP-pc-ASPECTS were associated with favorable outcome. Patients who underwent thrombectomy had a higher likelihood of favorable outcome with increasing CAPS (T > 6 s) compared to control (P = 0.048 for continuous variable). When CAPS (T > 6 s) was treated as a categorical variable, the interaction remained significant (P = 0.03). Similarly, the treatment effect was also modified by PMT hypoperfusion (T >6 s) (P = 0.03). In patients with CAPS (T >6 s) >3 or with PMT hypoperfusion (T >6 s), thrombectomy was associated with favorable outcome.

Interpretation: Higher CAPS correlated with a decrease in the rate of favorable outcomes. However, patients with higher CAPS were more likely to benefit from thrombectomy compared to medical management alone, suggesting that severe hypoperfusion should not preclude endovascular treatment. ANN NEUROL 2025;98:185-196.