BP reductions during endovascular therapy (EVT) have been associated with infarct progression and worse outcome after 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 timing of BP reductions during hyperacute period of stroke.

To evaluate relation of blood pressure (BP) reductions during hyperacute period of large vessel occlusion (LVO) stroke with infarct progression and functional outcome.

Patients with LVO undergoing EVT were prospectively enrolled. High frequency BP was recorded using non-invasive finger plethysmography. Patients underwent initial CT perfusion and MRI at 24 hours to calculate infarct growth. Exposure variables were defined as: difference between admission MAP and lowest MAP (ΔMAP), MAP drop > 20%, MAP < 70 mmHg, and SBP < 140 mmHg. Functional outcome was measured with modified Rankin Scale (mRS) at 90 days. Associations between BP reductions and outcomes were studied using linear regression and logistic regression models.

45 patients underwent continuous BP monitoring (age 72±17; 58% female; NIHSS 13±6). Aggregated time series data revealed marked BP reduction around the time of imaging from which patients recovered and sustained decrease in BP after groin puncture without return to baseline. Linear regression analysis revealed 13 ml infarct growth for every 10mmHg 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). 

Marked 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.