Abstract 77: Perihematomal Edema Expansion Rate is Associated With Poor Functional Outcomes in Basal Ganglia Intracerebral Hemorrhage

Abstract

Background: Perihematomal edema (PHE) has been associated with poor outcomes in deep spontaneous intracerebral hemorrhage (ICH). However, it is unknown if specific deep location (thalamus versus basal ganglia) modifies the effect of PHE on functional outcome. Methods: We used data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 (ATACH-2) trial. We included patients who had deep ICH and available neuroimaging and 3-month functional outcome data. We calculated the 24-hour PHE expansion rate as the difference in PHE volume between baseline and 24-hour CT scan divided by hours between scans. We used logistic regression models to evaluate the relationship between PHE expansion rate (natural-log transformed) and poor outcome (3-month modified Rankin Scale [mRS] score 4-6), with subgroup analyses to determine the effect of thalamic vs basal ganglia location on this association. Results: Out of 1000 subjects enrolled in ATACH-2, 870 (87%) had supratentorial, deep ICH. Of these, 754 (87%) had complete neuroimaging and outcome data (thalamus n=324, basal ganglia n=430). Overall, PHE expansion rate was associated with poor outcome in univariable (OR 1.3, 1.2-1.5, p<0.001) but not multivariable models (OR 1.1, 0.9-1.3, p=0.24). Median PHE expansion rate was faster in basal ganglia versus thalamic ICH (0.03 [0.09] mL/hr vs 0.01 [0.04] mL/hr, p<0.001). In basal ganglia ICH, PHE expansion rate was associated with poor outcome (OR 1.4, 1.1-1.8, p=0.01) in a multivariable model including age, sex, race, admission GCS, ICH volume (natural log-transformed), presence of intraventricular hemorrhage (IVH), hematoma expansion, time to baseline scan, and treatment group. In thalamic ICH, PHE expansion rate was not associated with poor outcome in multivariable analysis (OR 0.9, 0.7-1.2, p=0.44). Conclusions: In the ATACH-2 trial population, 24-hour PHE expansion rate was associated with poor functional outcome among basal ganglia, but not thalamic, bleeds. These results provide further evidence that PHE is associated with functional outcomes and supports the existence of effect modification by the specific deep location involved.