Abstract 99: Impact of Acute Perihematomal Edema on Long Term Outcomes Following Primary Intracerebral Hemorrhage

Abstract

Introduction: The impact of acute perihematomal edema (PHE) as an independent predictor of clinical outcomes following an intracerebral hemorrhage (ICH) has been controversial. To date, some studies have reported that PHE is associated with poorer outcomes, while others have found an association with good outcomes. The goals of the current analysis were to 1) identify predictors of acute PHE, and 2) determine impact of PHE on clinical outcomes in a predominantly African American hypertensive ICH population. Methods: Subjects with spontaneous non-traumatic ICH who were prospectively enrolled in the DiffErenCes in the Imaging of Primary Hemorrhage based on Ethnicity or Race (DECIPHER) Project were included in the analysis. Baseline MRIs were performed in subjects at median of 2 days from onset. Hematoma volume as well as PHE were calculated from GRE and FLAIR sequences, respectively, employing a semiautomated volumetric analysis. PHE volume was expressed as a percent of the hematoma volume (PHEv/ICHv x 100). Outcome measures included year 1 NIHSS score using a log-linear model and dichotomized (0-2 vs. 3-6) modified Rankin Scale (mRS) using a logistic regression model. Results: A total of 140 subjects were included in the analysis. Mean age was 59, 58% were male, 75% were black, and 85% had a history of hypertension. Baseline NIHSS score was mean 9 (median 6), mean ICH volume was 25 cc (range 0.5-136 cc), and mean relative PHE percent was 115% (range 0-559%). Independent predictors of PHE on multivariate analysis included ICH volume (p=0.004) and antiplatelet use on admission (p=0.02). At the year 1 timepoint, there was no significant association between the severity of PHE percent and good or poor outcome based on dichotomized mRS (p=0.67); however there was a modest trend towards an association between increased edema and lower NIHSS scores (p=0.15). Conclusions: In this large MRI-based cohort of patients with primary ICH, acute perihematomal edema measured on FLAIR sequences was not an independent predictor of poor functional outcome at year 1 employing the mRS. However, there was a modest trend towards an association between increased relative edema volume and lower year 1 NIHSS scores, which may suggest a protective effect of edema on outcome. Further studies in a larger cohort are needed to clarify the impact of both acute and peak perihematomal edema on outcome following primary ICH.