Perfusion Imaging Predicts Favorable Outcomes after Basilar Artery Thrombectomy.

OBJECTIVE Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (Time-to-maximum [Tmax] delay >10 seconds) would have a favorable response to ET compared to patients with more extensive regions involved. METHODS We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We pre-specified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax >10s) in cerebellum (1 point/hemisphere), pons (2 points), midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS≤3) and unfavorable (CAPS>3) groups. The primary outcome was a favorable functional outcome 90-days after ET (modified Rankin Scale [mRS] 0-3). RESULTS 103 patients were included. CAPS≤3 patients (87%) had a lower median NIHSS (12.5 [IQR 7-22]) compared to CAPS>3 patients (13%) (23 [IQR 19-36]; p=0.01). Reperfusion was achieved in 84% of all patients with no difference between CAPS groups (p=0.42). 64% of reperfused CAPS≤3 patients had a favorable outcome compared to 8% of non-reperfused CAPS≤3 patients (OR=21.0 [95% CI 2.6-170]; p 3 patients had a favorable outcome, regardless of reperfusion. In a multivariable regression analysis, CAPS≤3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR 39.25 [95% CI 1.34->999)]; p=0.04). INTERPRETATION BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. This article is protected by copyright. All rights reserved.