Abstract WMP89: CT Hypodensities in Acute Intracerebral Hemorrhage Predict Hematoma Expansion

Abstract

Introduction: Hematoma expansion (HE) is a potentially modifiable predictor of poor outcome following acute intracerebral hemorrhage (ICH) and a common therapeutic target in recent and ongoing clinical trials. Our ability to identify ICH patients likeliest to expand and therefore likeliest to benefit from HE-targeted treatments remains an unmet need. Hypodensities (hDs) within ICH on noncontrast CT (NCCT), sometimes referred to as “swirl sign,” have been suggested as a possible predictor of HE. We sought to determine whether hDs can predict HE independently of other known predictors of HE. Methods: hDs were analyzed by 2 independent blinded raters in consecutive ICH patients with baseline CT/CT Angiography (CTA) and follow-up NCCTs. The association of hDs and HE (>6cc or 33% of baseline volume) was determined by multivariable logistic regression controlling for other variables (including the CTA spot sign) associated with HE in univariate analyses with p≤ 0.1. Results: Among 414 patients, 114 (27.5%) baseline NCCTs demonstrated hDs (Figure, white arrowheads; kappa for interrater reliability 0.87). In univariate analyses, hDs were strongly associated with HE (40.3% hDs in patients with HE, 10.3% in patients without, p<0.0001) and with warfarin use, shorter time to CT, larger baseline ICH volume, CTA spot sign presence, and older age. The association between hDs and HE remained significant (OR = 2.89 [95%CI 1.5-5.6], p=0.001) in a multivariable model controlling for the above factors and sex; other independent predictors of HE were CTA spot sign, shorter time to CT and older age (all p<.001). Discussion: hDs within an acute ICH on NCCT are a reliable and strong predictor of HE, independent of other clinical and imaging predictors. This novel marker may help clarify the mechanism of HE and serve as a useful addition to clinical algorithms for determining HE risk.