Abstract P424: Hemorrhage Enlargement in the First Two Hours: A Mobile Stroke Unit Study

Abstract

Objective: Hematoma enlargement (HE) occurs after spontaneous intracerebral hemorrhage (ICH) but no studies have evaluated the frequency of HE in first 1-2 h after symptom onset. We evaluated HE in the first 2h after onset using a mobile stroke unit (MSU). Methods: Patients with spontaneous ICH within 4.5h were evaluated on the Houston MSU between 5/2014 and 4/2020. Baseline CT scans from the MSU were compared with scans repeated within 1h [median 67min (IQR 57-82 min]. Significant HE was defined as >6 ml if baseline volume was <20 ml and 30% increase if baseline volume >20 ml. Kruskal-Wallis and Wilcoxon rank sum tests evaluated differences in baseline volumes and HE. Intraclass correlation coefficient (ICC) evaluated agreement between two ICH measurement techniques (ABC/2 vs semi-automated). Results: 163 patients had baseline CTs, of whom 60 had repeat 1h CTs (table 1). There was no difference between baseline volume and time of CT from symptom onset {<1h vs 1-2h vs >2h median (IQR) = 14 ml (6-28) vs. 16 ml (7-32) vs. 12 ml (4-24), P=0.42)}. There was also no correlation between time from onset and difference in volume between baseline and 1 h repeat imaging. However, 9/60 patients had significant HE from baseline to 1 h repeat imaging; all of these occurred in patients initially imaged within 2 h of onset (6/24 within 1h, 3/20 within 1-2h) (P=0.03) (figure 1). High reliability was seen between the two methods measuring volumes (ICC = 0.84). Conclusion: Significant HE in the next hour occurs in 25% of ICH patients imaged within the first hour after symptom onset, and 17% imaged between 1-2 hours of onset. These patients would be a target for ultra-early hemostatic intervention.