Abstract 76: Intensive Blood Pressure Reduction is Associated With Reduced Hematoma Expansion in Deep Intracerebral Hemorrhage: A Secondary Analysis of ATACH-2

Abstract

Introduction: Hypertension is the strongest risk factor for spontaneous intracerebral hemorrhage (ICH) involving deep brain regions. We tested the hypothesis that intensive blood pressure (BP) treatment reduces hematoma expansion and improves functional outcomes in deep ICH, and evaluated whether this effect is modified by the specific deep structure involved (thalamus versus basal ganglia). Methods: We performed a secondary analysis of data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 (ATACH-2) trial, which randomly assigned ICH patients with symptom onset within 4.5 hours and hematoma volume <60mL to either intensive treatment (systolic BP target 110-139 mm Hg) or standard treatment (target 140-179 mm Hg). Significant hematoma expansion was defined as a >33% increase in volume between baseline and 24-hour CT. We used chi-square and Mann–Whitney U tests and logistic and ordinal logistic regression models as appropriate. Results: Of 1000 trial subjects, 870 (87%) had deep ICH, of whom 780 (90%) had complete neuroimaging/outcome data (thalamus n=336, basal ganglia n=444) and 405 (52%) were randomized to intensive treatment. Significant hematoma expansion was less frequent in the intensive vs standard arm (17% vs 26%, p=0.008). Intensive treatment was associated with a lower risk of significant hematoma expansion (OR 0.6, 95% CI 0.4-0.9; p=0.01) even in multivariable models (OR 0.6, 95% CI 0.4-0.9; p=0.01) including age, sex, baseline INR and time to scan. This treatment effect was modified by the specific deep location of the ICH (interaction p=0.02): there was less hematoma expansion with intensive versus standard treatment among basal ganglia bleeds (0.4 [IQR 2] mL vs 0.9 [IQR 6] mL, p=0.002) but not among thalamic bleeds (0.3 [IQR 2] mL vs 0.4 [IQR 2] mL, p=0.48). Intensive treatment was not associated with a shift in the distribution of 3-month modified Rankin Scale scores (overall p=0.9, basal ganglia p=0.9, thalamus p=0.8). Conclusions: Compared to standard treatment, intensive BP reduction was associated with less hematoma expansion in deep ICH, specifically among hemorrhages located in the basal ganglia. In this underpowered subgroup analysis, intensive BP reduction was not associated with improved outcomes.