Abstract 51: Impact of Cerebral Autoregulation on the Relationship Between Blood Pressure Variability and Functional Outcome Following Endovascular Thrombectomy

Abstract

Background: Both increased blood pressure (BP) variability and impaired autoregulation have been linked to worse outcome after endovascular thrombectomy (EVT). This study examined the combined effect of these variables on the risk of poor outcome in patients with large-vessel occlusion (LVO) stroke. Methods: Autoregulation was continuously measured for up to 24 hours after EVT and quantified as a moving correlation coefficient between arterial BP and the near-infrared spectroscopy-derived cerebral oxygen saturation. Systolic BP variability was assessed using the standard deviation of the mean. Values were averaged for the entire recording period and dichotomized at the lowest tertile for both variables. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days and dichotomized into good (mRS 0-2) and poor outcome (mRS 3-6). Results: We included 195 patients (mean age 70 + 16, 45% female, mean NIHSS 14, mean monitoring time 15 + 7 hours). After adjusting for age, NIHSS, ASPECTS, and TICI score, patients with low BP variability and intact autoregulation were significantly more likely to achieve a good outcome than those with high BP variability and impaired autoregulation (OR 3.7, 95% CI 1.2-12.1, p=0.028, Figure 1A). We found an interaction between BP variability and autoregulation (p=0.067). Patients with high BP variability showed a gradual decrease in the probability of a good outcome with worsening autoregulation. However, for patients with low BPV, autoregulation had minimal impact. (Figure 1B). No significant correlation was seen between autoregulatory function and BP variability (r=0.07, p=0.33). Conclusions: For LVO stroke patients with high BP variability after EVT, worse 90-day functional outcome may be exacerbated by impaired autoregulation. These results suggest that autoregulatory status should be considered in the management of BP after EVT to identify high-risk patients and develop individualized treatment strategies.