Oedema extension distance in intracerebral haemorrhage: Association with baseline characteristics and long-term outcome.

Abstract

Oedema extension distance is a derived parameter that may reduce sample size requirements to demonstrate reduction in perihaematomal oedema in early phase acute intracerebral haemorrhage trials. We aimed to identify baseline predictors of oedema extension distance and its association with clinical outcomes. Using Virtual International Stroke Trials Archive-Intracerebral Haemorrhage, first Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial, and Minimally Invasive Surgery and rtPA for Intracerebral Hemorrhage Evacuation II datasets, we calculated oedema extension distance at baseline and at 72h measured using computed tomography. Using linear regression, we tested for associations between baseline characteristics and oedema extension distance at 72h. Ordinal regression (underlying assumptions validated) was used to test for associations between oedema extension distance at baseline and 72h and oedema extension distance change between baseline and 72h, and modified Rankin scale scores at 90 days, adjusted for baseline and 72h prognostic factors. There were 1028 intracerebral haemorrhage cases with outcome data for analyses. Mean (standard deviation, SD) oedema extension distance at 72h was 0.54 (0.26)cm, and mean oedema extension distance difference from baseline (EED72-0) was 0.24 (0.18)cm. Oedema extension distance at 72h was greater with increasing baseline haematoma volume and baseline oedema extension distance. Increasing age, lobar haemorrhage, and intraventricular haemorrhage were independently associated with EED72-0. In multifactorial ordinal regression analysis, EED72-0 was associated with worse modified Rankin scale scores at 90 days (odds ratio 1.96, 95% confidence interval 1.00-3.82). Increase in oedema extension distance over 72h is independently associated with decreasing functional outcome at 90 days. Oedema extension distance may be a useful surrogate outcome measure in early phase trials of anti-oedema or anti-inflammatory treatments in intracerebral haemorrhage.