Association Between Collateral Status, Blood Pressure During Thrombectomy, and Clinical Outcomes in Patients With Basilar Artery Occlusion.

Background And Objectives: We investigated the relationship between intraprocedural blood pressure (BP) and clinical outcomes in patients with basilar artery occlusion (BAO) undergoing endovascular treatment (EVT), exploring whether it is modifiable by collateral status.

Methods: Patient data from the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) randomized trial were analyzed for those with BAO who received EVT. Intraprocedural BP data were extracted, with collateral status assessed using the Basilar Artery on CT Angiography (BATMAN) score (BATMAN score ≥7 favorable collateral status, <7 unfavorable). Associations between BP parameters and outcomes were assessed using multivariable logistic regression and restricted cubic splines. The effect modification was assessed using an interaction term between BP parameters and collateral status. The primary outcome was a favorable outcome defined by a modified Rankin Scale (mRS) score of 0-3 at 90 days.

Results: There were 212 patients included (median age 68 years, 32.1% female). Restricted cubic spline analysis showed that the SDs of systolic BP (SBP) and mean arterial pressure (MAP) had J-shaped relationships with favorable outcome ( for nonlinearity = 0.004 and <0.001, respectively), with inflection points at 12 and 8 mm Hg, respectively. Multivariable logistic regression showed that MAP of 80-110 mm Hg (adjusted odds ratio [aOR] 3.00, 95% CI 1.46-6.35) and MAP SD <8 mm Hg (aOR 2.28, 95% CI 1.24-4.25) were associated with favorable outcome. Significant interactions with collateral status were observed for MAP SD <8 mm Hg, SBP SD <12 mm Hg, MAP drop >20%, and minimum MAP and SBP (all < 0.05). After Holm-Bonferroni correction, only the interaction between collateral status and MAP <80 mm Hg remained significant (corrected = 0.036). In patients with unfavorable collateral status, MAP <80 mm Hg was associated with decreased probability of favorable outcome (aOR 0.04, 95% CI 0.00-0.21) while this association was not observed in patients with favorable collaterals.

Discussion: For patients with BAO undergoing EVT, intraprocedural MAP between 80 and 110 mm Hg was associated with favorable outcome while MAP <80 mm Hg was associated with a lower probability of favorable outcome, especially in patients with unfavorable collateral status.