Defining hematoma expansion in intracerebral hemorrhage: relationship with patient outcomes

Hematoma expansion (HE) is a surrogate marker in intracerebral hemorrhage (ICH) trials. However, the amount of HE necessary to produce poor outcomes in an individual is unclear; there is no agreement on a clinically meaningful definition of HE. We compared commonly used definitions of HE in their ability to predict poor outcome as defined by various cutpoints on the modified Rankin Scale (mRS). In this cohort study, we analyzed 531 patients with ICH from the Virtual International Stroke Trials Archive. Primary outcome was mRS at 90 days, dichotomized into 0–3 vs 4–6. Secondary outcomes included other mRS cutpoints and mRS “shift analysis.” Sensitivity, specificity, and predictive values for commonly used HE definitions were calculated.