Abstract T P48: Neuroimaging Markers of Swelling Predict Outcome After Acute Ischemic Stroke
Introduction: In malignant infarction, brain edema leads to secondary neurological deterioration and poor outcome. We investigated whether swelling is associated with outcome in a broader range of stroke severity.
Methods: Two research cohorts (NBO and EPITHET) comprising 98 acute stroke subjects with prospective serial brain magnetic resonance imaging (MRI) were analyzed. The categorical presence of swelling and/or infarct growth (IG) was assessed on diffusion weighted MRI (DWI) by comparing baseline and 3-5 day follow-up scans. IG was defined using the ASPECTS system (small IG = decrease in ASPECTS ≥ 1; large IG = decrease in ASPECTS ≥ 2). The increase in lesion volume (ΔDWI) was then subdivided into swelling and IG volumes using region-of-interest analysis. The relationship of these imaging markers with outcome was evaluated using univariate and multivariate regression, with poor outcome defined as a 90 day modified Rankin Scale score of 3-6. Receiver operating characteristic (ROC) curve analysis was undertaken to define a threshold for prediction of poor outcome.
Results: The presence of swelling independently predicted poor outcome after adjustment for age, admission NIH stroke scale score, admission glucose, and baseline DWI volume (OR4.55, 95%CI 1.21-18.9, p<0.02). Volumetric analysis confirmed ΔDWI was associated with outcome (OR4.29, 95%CI 2.00-11.5, p<0.001). After separating ΔDWI into swelling and IG volumes, swelling remained an independent predictor of poor outcome (OR1.15, 95%CI 1.02-1.43, p<0.02). While large IG was associated with poor outcome (OR7.05, 95%CI 1.04-143, p=0.045), small IG was not. ROC curve analysis identified a swelling volume of ≥11mL as the threshold with greatest sensitivity (77%) and specificity (75%) for predicting poor outcome (AUC=0.798).
Conclusions: Both swelling and IG contribute to total lesion growth in the days following stroke. Swelling is an independent predictor of poor outcome in moderate to severe stroke.
Author Disclosures: T.W.K. Battey: None. M. Karki: None. A.B. Singhal: Research Grant; Significant; NIH-NINDS R01NS051412; P50NS051343; R21NS077442. O. Wu: Research Grant; Significant; NIH/NINDS R01NS059775, P50 NS051343, R01 NS051412. S. Sadaghiani: None. B.C.V. Campbell: None. S.M. Davis: Honoraria; Modest; Lectures sponsored by Boehringer Ingelheim, Covidien, Pfizer, Siemens. Consultant/Advisory Board; Modest; Boehringer Ingelheim. G.A. Donnan: None. K.N. Sheth: Research Grant; Significant; Remedy Pharmaceuticals, Inc. W.T. Kimberly: Research Grant; Significant; NIH/NINDS K23NS076597, Remedy Pharmaceuticals, Inc..
- © 2015 by American Heart Association, Inc.