Abstract TMP89: Impaired Cerebral Autoregulation Increases Risk of Worse Outcome After Endovascular Thrombectomy in Stroke Patients With High Blood Pressure Variability

Abstract

Introduction: Both increased blood pressure (BP) variability and impaired autoregulation have been associated with increased risk of poor outcome after endovascular thrombectomy (EVT). The combined effect of these two variables, however, has not yet been elucidated. We hypothesized that the detrimental effects of high BP variability may be amplified by impaired autoregulation. Methods: We prospectively enrolled patients with large-vessel occlusion (LVO) stroke undergoing EVT. Autoregulatory function was continuously measured for up to 48 hours post-EVT by interrogating changes in near-infrared spectroscopy-derived tissue oxygenation (a cerebral blood flow surrogate) in response to changes in BP (Fig. 1A). BP variability was assessed using the standard deviation of the mean. Values were averaged for the entire recording period and dichotomized based on the median. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days. We examined the association between BP variability, autoregulatory function, and outcome using ordinal logistic regression, adjusting for age and admission NIHSS. Results: Ninety-five patients (mean age 71, NIHSS 14, monitoring time 28±18 hours) were included. BP variability (p=0.043) and autoregulation (p=0.04) were each independently associated with functional outcome. Among patients with high BP variability, worse autoregulation was independently associated with higher (worse) mRS scores at 90 days (OR 3.9, 95% CI 1.1-14.5, p=0.036; Fig. 1B). The proportion of favorable outcome was highest among patients with low BP variability and better autoregulation, and lowest among those with high BP variability and worse autoregulation (p=0.073; Fig. 1C). Conclusion: For LVO stroke patients with high BP variability after EVT, worse functional outcome may be exacerbated by impaired autoregulation. These results suggest that autoregulatory status should be considered in the management of BP after EVT.