Abstract Body: Objective: Hematoma expansion (HE) predicts disability and death after intracerebral hemorrhage (ICH). Platelet activity is essential for coagulation, and the use of anti-platelet medication (e.g., aspirin, NSAIDs) is associated with increased HE. The impact of pre-ICH anti-platelet medication on HE is incompletely understood. Specific biomarkers of platelet activity would improve our understanding of HE and could point towards targeted treatments. We tested the hypothesis that biomarkers of platelet activity predict subsequent HE.

Methods: We prospectively identified patients with spontaneous ICH within 12 hours of symptom onset and measured whole blood with TEG 6s platelet mapping assays to assess platelet function (Hemonetics Inc.). We assessed heparinase kaolin (HKH) to determine the total platelet activation. We measured activated fibrinogen polymerization (ActF) to determine the fibrinogen component. Hematoma volumes for initial and follow-up CTs were calculated using a validated semi-automated method. HE was calculated by measuring the difference in hematoma volume between scans. We calculated the correlation between HE and platelet activity using Spearman’s rank correlation. We constructed a linear regression model to predict HE from ActF and an ActF by pre-ICH anti-platelet interaction term. The interaction term tests the hypothesis that there is an interaction between ActF and HE that varied with pre-ICH anti-platelet medication.

Results: There were 38 patients from three metropolitan sites. Fourteen (36.8%) were known to take pre-ICH anti-platelet medication. HKH was negatively correlated with HE (r = -0.30, CI [-0.63, 0.04], P = 0.03), indicating more HKH activity predicted less HE. Results for ActF were dependent upon whether the patient took pre-ICH anti-platelet medication (interaction P = 0.005), where HE was the dependent variable and independent variables included ActF and pre-ICH anti-platelet medication.

Discussion: Hemostatic biomarkers predicted subsequent HE in patients with ICH. The association of ActF with HE was dependent on aspirin or NSAIDs use. Potential interventions that improve platelet activity in patients that are high risk for HE deserves further study.

Applying for the Mordecai Y. T. Globus New Investigator Award in Stroke