Abstract MP36: Blood Pressure Reductions in the Hyperacute Phase of Large Vessel Occlusion Ischemic Stroke Are Associated With Infarct Progression and Poor Functional Outcome

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Introduction: Decreases in blood pressure (BP) during endovascular therapy (EVT) have been associated with infarct progression and worse outcome after large vessel occlusion (LVO) stroke. However, BP trajectories in the hyperacute phase prior to EVT have not been well characterized. We used high-frequency BP and hemodynamic monitoring to study the timing of BP reductions during the hyperacute period of stroke and evaluated their relation to infarct progression and functional outcome. Methods: We prospectively enrolled patients with anterior circulation LVO stroke undergoing EVT. BP and cardiac hemodynamic variables were recorded every 20 seconds from ER admission until the end of EVT using non-invasive finger plethysmography. Patients underwent initial CT perfusion imaging and a follow-up MRI at 24 hours to calculate infarct growth. The following hemodynamic parameters were defined as exposure variables: the difference between admission MAP and lowest MAP (ΔMAP), MAP drop> 20% from admission, MAP<70 mmHg, and SBP<140 mmHg. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days. Core associations between BP reductions and outcomes were studied using linear regression and logistic regression models. Results: 45 patients underwent continuous BP monitoring (age 72±17; 58% female; NIHSS 13±6). Aggregated time series data revealed a marked BP reduction around the time of imaging from which patients recovered (mean SBP 33 mmHg, duration 18 min). A sustained decrease in BP was observed after groin puncture without return to baseline BP levels. A linear regression analysis revealed a 13ml infarct growth for every 10 mmHg reduction in ΔMAP (p=0.054). Patients were divided into two groups based on median ΔMAP = 29. Those with ΔMAP ≤29 had better functional outcome at 90 days (34.78% vs. 9.09%, p = 0.038). Conclusion: Marked and frequently iatrogenic BP reductions occur around the time of initial imaging and may present a potential target for therapeutic intervention. Decrease in blood pressure before reperfusion may increase the risk of infarct progression and poor functional outcome. Changes in cardiac hemodynamic variables throughout the acute stroke period suggest a potential role for fluid resuscitation for hemodynamic optimization.