Abstract 110: Pre-Endovascular Therapy Change in BP is Associated With Outcome: A post-Hoc Analysis of the Blood Pressure After Endovascular Treatment (BEST) Prospective Cohort Study

Background: Higher blood pressure on admission is associated with worse outcomes in stroke patients undergoing endovascular therapy (EVT). However, if BP changes pre-EVT affects outcomes remains unknown. We sought to determine this association in the prospective multi-institutional cohort study, Blood Pressure after EVT in Stroke (BEST). Methods: We enrolled consecutive adult patients in BEST with acute ischemic stroke who underwent clot retrieval from ICA, M1, or M2 from Nov 2017 to May 2018 at 12 comprehensive stroke centers. Study variables included change in mean arterial pressure (MAP) from admission to immediately pre-EVT. Primary outcomes was dichotomous 90-day modified Rankin score [mRS] 0-2 (good outcome) vs. 3-6 (bad outcome). We determined the association between any decrease or increase in MAP (delta MAP = Pre-EVT MAP – Admission MAP) and poor outcome (defined by mRS 0-2) using univariate and multivariable analysis (adjusted for age, NIHSS score, TICI score, and time to reperfusion). Results: Among 443 patients, 218 patients had data on pre-EVT BP (missing: n = 61) and 90-day mRS (missing: n = 164). The mean age was 68.8±14.6; 52.3% were women; median NIHSS was 16.5 (IQR 12-21). Baseline characteristics and outcomes are reported in table 1. In multivariable models, each mmHg increase or decrease in MAP was associated with higher odds of worse outcome (OR 1.05, 95% CI 1.002-1.10, p=0.042 and OR 1.06, 95% CI 1.01-1.11, p=0.021, respectively). (Table 2) Conclusion: We found a “U” shape association between pre-EVT change in MAP and poor outcome (Figure). While a drop in MAP may lead to infarct growth, an increase in MAP maybe a sign of failing collaterals and worsening ischemia. Future studies are needed to determine the best BP target pre-endovascular treatment.