BackgroundElevated systolic blood pressure (SBP) in the acute phase after endovascular therapy (EVT) is associated with worse outcome. However, the association between systolic blood pressure reduction (SBPr) and the outcome of EVT is not well understood.ObjectiveTo determine the association between SBPr and clinical outcomes after EVT in a prospective multicenter cohort.MethodsA post hoc analysis of the Blood Pressure after Endovascular Stroke Therapy (BEST) prospective observational cohort study was carried out. SBPr was defined as the absolute difference between admission SBP and mean SBP in the first 24 hours after EVT. Logistic regression was used to assess the association between SBPr and poor functional outcome (modified Rankin Scale score 3–6) at 90 days.ResultsA total of 259/433 (58.5%) patients had poor outcome. SBPr was higher in the poor outcome group than in the good outcome group (26.6±27.4 vs 19.0±22.3 mm Hg; p<0.001). However, in adjusted models, SBPr was not independently associated with poor outcome (OR=1.00 per 1 mm Hg increase, 95% CI 0.99 to 1.01) or death (OR=0.9 per 1 mm Hg increase; 95% CI 0.98 to 1.00). No association remained when SBPr was divided into tertiles. Subgroup analyses based on history of hypertension, revascularization status, and antihypertensive treatment yielded similar results.ConclusionThe reduction in baseline SBP following EVT was not associated with poor functional outcomes. Most of the cohort (88%) achieved successful recanalization, and therefore, these results mainly apply to patients with successful recanalization.