Abstract Body: Background: The deleterious effects of intensive blood pressure (BP) lowering in patients who achieved successful reperfusion may result from high BP variability (BPV). However, there is still uncertainty regarding whether the association between high BPV and poor outcomes indicates a causal relationship or if high BPV is merely a bystander or consequence of various factors associated with poor outcomes. We investigated whether the association between intensive BP management after endovascular therapy (EVT) and unfavorable functional outcomes is mediated by BPV.

Methods: This is a secondary analysis of OPTIMAL-BP (The Outcome in Patients Treated with Intra-Arterial Thrombectomy-Optimal Blood Pressure Control), comparing intensive and conventional systolic BP (SBP) management for functional outcomes in patients with successful reperfusion post-EVT. Multivariable logistic regression analysis was conducted for the association between BPV and outcomes including 90-day modified Rankin Scale (mRS), symptomatic intracranial hemorrhage (sICH), and final infarction volume. Mediation analysis was performed to evaluate the causal inference whether the relationship between intensive BP management and the 90-day mRS is mediated by BPV.

Results: The 24-hour time rate (TR) of SBP was significantly higher in the intensive BP management group. Higher TR was significantly associated with an unfavorable ordinal shift of the 90-day mRS (adjusted OR [aOR] 1.19, 95% CI 1.06–1.33, P=0.003). High TR significantly increased the final infarction volume (coefficient 24.03, 95% CI 6.50–41.56, P=0.007), but did not increase the risk of sICH. TR fully mediated the association between intensive BP management and functional outcomes. The proportions of the association explained by TR was 32.15%.

Conclusions: TR mediated the association of intensive BP management for 24 hours and poor functional outcome in successfully reperfused ischemic stroke patients. Efforts to modulate BPV after EVT may be helpful in improving clinical outcomes.