Sex Differences in Blood Pressure Dynamics and Outcomes After Endovascular Thrombectomy

BACKGROUND AND OBJECTIVES: Optimal blood pressure (BP) management after endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) remains controversial, and whether early BP dynamics differentially affect outcomes among female and male participants is unclear. METHODS: This was an exploratory secondary analysis of ENCHANTED2/MT, a multicenter, open-label, blinded-end point randomized trial conducted in 44 tertiary hospitals in China. Eligible adults had AIS due to large-vessel occlusion, successful reperfusion after EVT, and persistent elevated systolic BP (SBP) within 3 hours after reperfusion. Serial BP measurements obtained during the first 72 hours after randomization were used to estimate patient-specific mean BP trajectories and short-term BP variability with a location-scale mixed-effects modeling approach. Associations of mean BP, BP variability, and randomized intensive vs standard BP lowering strategy with clinical outcomes were examined, with sex being evaluated as an effect modifier. The primary outcome was the 90-day modified Rankin Scale (mRS). RESULTS: Among 816 patients (mean age 67.6 ± 12.0 years; 38% female), intensive BP management was associated with worse 90-day ordinal mRS outcome among male participants (adjusted common odds ratio [acOR] 1.91; 95% CI 1.29-2.83), whereas the corresponding estimate among female participants was closer to null (acOR 0.94; 95% CI 0.56-1.57; ratio of acORs 0.49; 95% CI 0.26-0.94). In separate postrandomization BP exposure models, each 5 mm Hg higher mean SBP was associated with worse 90-day mRS outcome among male participants (acOR 1.11; 95% CI 1.03-1.20), whereas no clear adverse association was observed among female participants (acOR 0.95; 95% CI 0.85-1.05; ratio of acORs 0.85; 95% CI 0.75-0.97). SBP variability showed weaker and less consistent sex differential associations. Findings across secondary outcomes were directionally similar but exploratory. DISCUSSION: In this exploratory secondary analysis of ENCHANTED2/MT, randomized BP management strategy and early post-thrombectomy BP dynamics showed sex-stratified associations with outcomes. These associations may reflect biological sex and sex-related differences in baseline clinical and vascular characteristics. These findings are hypothesis generating and should be confirmed in prospectively designed studies before informing sex-specific BP management after EVT. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov number, NCT04140110; the Registration Date, October 22, 2019.