Abstract Number ‐ 162: Hydration Status and Functional Outcomes in Patients with Large Vessel Occlusion Stroke Undergoing Endovascular Therapy

Introduction Large vessel occlusion (LVO) and dehydration are both independently associated with poor functional outcomes and increased odds of mortality in acute ischemic stroke. Dehydration has previously been shown to affect collateral blood flow in LVO stroke, but it is unclear if this leads to worsened clinical outcomes. Methods A stroke center registry (10/2019‐12/2021) of consecutive adults who had undergone successful endovascular therapy (EVT, with thrombolysis in cerebral infarction score 2b/3) for anterior circulation LVO (ICA, M1, or M2) was queried. Dehydration on presentation was defined using laboratory surrogates: blood urea nitrogen/creatinine ratio >15 or serum osmolality >296 mOsm/kg. The primary outcome was a favorable shift in 90‐day modified Rankin Scale (mRS) using a proportional odds model, adjusting for age, pre‐stroke mRS, National Institutes of Health Stroke Scale (NIHSS), and Alberta Stroke Program Early Computed Tomography Scale (ASPECTS). Secondary outcomes included early improvement in 24h NIHSS. Results Of the 318 patients with anterior LVO who underwent EVT, 206 (65%) met criteria for dehydration, and 181 (87.9%) had both mRS and ASPECTS data available. Younger age, lower NIHSS, lower mRS, and higher ASPECTS were all strongly and independently associated with a favorable shift in 90d mRS. Dehydrated patients had similar changes in 24‐hr NIHSS scores (‐5 [interquartile range, IQR ‐10 to 0] vs. ‐5 [IQR ‐8 to 0], p = 0.37). Dehydration was not associated with a less favorable shift in 90‐day mRS (odds ratio [OR] 0.74, 95% confidence interval [CI] 0.41‐1.33), which remained non‐significant after multivariable adjustment (OR 1.46, 95%CI 0.74‐2.86). With serum osmolality assessed continuously, higher serum osm was associated with a less favorable shift in mRS at 90d (OR 0.95, 95%CI 0.92‐0.99, p = 0.009), but this did not persist after multivariable adjustment (p = 0.92) and was driven by the association between higher osmolality and age (r = 0.24, p(bonferroni)< 0.01) and pre‐stroke mRS (r = 0.20, p(bonferroni) = 0.04). Conclusions There was no association between dehydration and lower odds of early clinical improvement or long‐term functional recovery following successful endovascular thrombectomy.