Abstract WP367: Effect of Early Blood Pressure Reduction on Infarct Size in Patients With Large Vessel Occlusion

Abstract

Introduction: In patients with large vessel occlusion presenting with acute ischemic stroke, cerebral perfusion is a major determinant of stroke severity. However, limited data exists to guide hemodynamic management of these patients early after presentation. In this study, we aim to evaluate the effect of blood pressure reductions during the hyper-acute period on infarct size. Methods: From a clinical stroke registry at a single comprehensive stroke center, we reviewed patients with middle cerebral artery (M1) or internal carotid artery occlusion who underwent hyperacute magnetic resonance imaging (MRI) for endovascular treatment decision in 2018. Infarct volume was determined by area of reduced apparent diffusion coefficient using RAPID software. Collateral circulation was scored based on baseline CT angiogram (good collaterals constituted >50% filling, poor collaterals ≤50% filling). Average mean arterial pressure (MAP) readings from the first hour of presentation were compared to average MAP readings from the hour prior to magnetic resonance imaging. For the purposes of our study, a drop of > 20% in the average MAP was regarded as a significant decrease. We hypothesized that both significant drop in MAP and the presence of good collateral circulation were independent predictors of infarct volume expressed as a logarithmic value in multivariable regression model. Results: Of the 35 patients (mean age 67, mean NIHSS 16) meeting inclusion criteria, 11% of patients experienced an early significant drop in MAP prior to time of MRI. Among patients with a significant drop in MAP, the average decrease was 35 mm Hg ±3.3 among those with significant drop from a baseline mean MAP of 125 mm Hg. In the multivariable analysis adjusting for collateral status, a significant drop in average MAP was independently associated with an increase in infarct volume (β = -0.727, p=0.0306). Collateral status also independently predicted infarct size (β=0.775, p=0.0007). Conclusion: Among ischemic stroke patients with large vessel occlusion, a >20% drop in MAP during the hyper-acute period is associated with larger infarct volumes. Further studies are needed to optimize early blood pressure management in these patients.