Abstract 94: Blood Pressure After Endovascular Stroke Therapy (BEST): Final Results of a Prospective Multicenter Cohort Validation Study

Abstract

Background: Limited data currently inform optimal post-endovascular therapy (EVT) blood pressure management. Systolic BP (SBP) >160 mmHg during the 24-hrs post-EVT correlated with worse outcomes in our retrospective multicenter study. To prospectively determine and potentially validate the specific post-EVT SBP threshold that discriminates functional outcomes, we designed a multicenter, prospective cohort study - “Blood Pressure after Endovascular Stroke Therapy (BEST)” - with a prespecified analysis plan. Methods: Consecutive EVT-treated adult patients with ICA, M1, or M2 occlusions were enrolled at 12 comprehensive stroke centers, excluding those with disability, terminal diagnoses, LVAD, and in-hospital stroke. Baseline, treatment characteristics, and all SBP values during the 24 hrs post-EVT were captured. The primary outcome was 90d mRS (0-2 vs 3-6) adjusted for age, baseline NIHSS, glucose, ASPECTS, time to reperfusion, and history of hypertension. Secondary outcomes were intracerebral hemorrhage (ICH), symptomatic ICH, mRS distribution, and early neurologic recovery (ENR). A sample size of 340 was calculated to provide 80% power to detect a 1.36 odds ratio (i.e., 8% difference in mRS 3-6 rate) at α=0.05; inflated to 450 patients for up to 25% loss to follow up. The threshold of peak SBP that best discriminates mRS 0-2 vs. 3-6 will be identified with Youden’s index, and its association with outcomes will be quantified using logistic regression. Subgroup analysis by mTICI score and associations of other BP parameters with outcomes will be explored. Missing 90d outcomes will be imputed. Results: We enrolled 457 patients from 11/2017 to 7/2018 with mean age 68y (±15), 52% females, median NIHSS 16 (IQR 11,20), and ASPECTS 8 (IQR 7,10). 221 (48%) patients received alteplase and 402 (88%) achieved mTICI 2b-3. Mean peak SBP was 165±24 mmHg in mTICI2b-3 group and 171±22 in mTICI 0-2a group, and 352 (77%) received an IV antihypertensive. 331 (73%) patients have outcomes available at 90d; rest are expected by 10/2018. Final results will be presented at ISC. Conclusion: Expected results from BEST will inform clinical care and guide a developing randomized trial of targeted antihypertensive treatment in EVT-treated stroke patients.