Autoregulation-Guided Blood Pressure Targets After Stroke Thrombectomy: Impact on Secondary Brain Injury and Neurologic Outcomes.

Abstract

The optimal blood pressure (BP) target after endovascular thrombectomy (EVT) remains elusive. The aim of our study was to assess the relationship between individualized autoregulation-based BP thresholds, secondary brain injury, and functional outcomes. We conducted a prospective observational study of patients with acute ischemic stroke who underwent EVT. Simultaneous recordings of arterial BP and near-infrared spectroscopy were used to continuously monitor each patient's limits of autoregulation for up to 24 hours. Time outside limits of autoregulation was correlated with short-term clinical end points, radiographic biomarkers of secondary brain injury, and functional outcomes. Personalized BP targets were successfully computed in 199 patients. Percent time outside limits of autoregulation was independently associated with early neurologic deterioration (OR 1.2, 95% CI 1.1-1.4, <i>p</i> < 0.001) and worse modified Rankin Scale scores at 90 days (OR 1.22, 95% CI 1.09-1.36, <i>p</i> < 0.001). Patients with hemorrhagic transformation and symptomatic intracranial hemorrhage spent significantly more time above the upper limit of autoregulation compared with those without (18.7% vs 11%, <i>p</i> = 0.02, and 24.9% vs 12.3%, <i>p</i> = 0.024, respectively). Furthermore, time above the upper limit of autoregulation was correlated with net water uptake, a radiographic biomarker of cerebral edema (β = 1.6, 95% CI 0.4-2.8, <i>p</i> = 0.009). In nonrecanalized patients, every 60 minutes below the lower limit of autoregulation was associated with an infarct progression of 16.2 mL (<i>p</i> < 0.001). Deviations from personalized BP targets were associated with an increased risk of secondary brain injury and worse functional outcomes. The study proposes autoregulation-oriented BP management as a promising strategy for improving recovery after ischemic stroke.