AbstractBackgroundThis study aimed to investigate the relationship between baseline blood pressure (BP) and clinical outcomes after thrombolysis for acute ischemic stroke (AIS) in different intracranial arterial stenosis subgroups.MethodsAIS patients from multicenter with intravenous thrombolysis were retrospectively enrolled from January 2013 to December 2021. We categorized participants into severe (≥ 70%) and nonsevere (< 70%) stenosis of major intracranial arteries subgroups. The primary outcome was unfavorable functional outcome defined as 3‐month modified Rankin Scale (mRS) ≥2. The association coefficients between baseline BP and functional outcomes were estimated in general linear regression model. The interactive effect was tested to determine the influence of intracranial arterial stenosis on the association between BP and clinical outcomes.ResultsA total of 329 patients were included. Severe subgroup was detected in 151 patients with average age of 70.5. Association between baseline diastolic BP (DBP) and unfavorable functional outcome in intracranial artery stenosis subgroups was significantly different (pfor interaction < .05). In nonsevere subgroup, higher baseline DBP was associated with higher risk of unfavorable outcome (OR 1.11, 95% CI 1.03 to 1.20,p= .009) compared with severe subgroup (OR 1.02, 95% CI 0.97 to 1.08,p= .341). Besides, intracranial artery stenosis also modified association between baseline systolic BP (SBP) and 3‐month death (pfor interaction < .05). In severe subgroup, higher baseline SBP was associated with decreased 3‐month death risk (OR 0.88, 95% CI 0.78 to 1,p= .044) compared with nonsevere subgroup (OR 1, 95% CI 0.93 to 1.07,p= .908).ConclusionsThe major intracranial artery state modulates association between baseline BP and 3‐month clinical outcomes after intravenous thrombolysis.