Association of Intensive Blood Pressure Reduction With Risk of Hematoma Expansion in Patients With Deep Intracerebral Hemorrhage

Key PointsQuestionDoes intensive blood pressure reduction decrease the risk of hematoma expansion and improve outcomes in patients with deep intracerebral hemorrhage? FindingsIn this exploratory analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage-2 randomized clinical trial, intensive blood pressure reduction was associated with a decreased risk of hematoma expansion in deep intracerebral hemorrhage, and this association was driven by hemorrhages located in the basal ganglia. No association with outcome was found in this population. MeaningIntensive blood pressure reduction was associated with a decreased risk of hematoma expansion, an important neuroimaging marker of primary brain injury, in patients with intracerebral hemorrhage that compromises the basal ganglia; however, intensive blood pressure reduction was not associated with improved outcomes. This exploratory analysis of Antihypertensive Treatment of Acute Cerebral Hemorrhage-2 randomized clinical trial data seeks to determine whether intensive blood pressure reduction is associated with decreased risk of hematoma expansion in patients with intracerebral hemorrhage and if these associations are modified by the specific deep-brain nuclei involved. ImportanceHypertension is the strongest risk factor for spontaneous intracerebral hemorrhage (ICH) involving deep brain regions, but it appears to be unknown if intensive blood pressure reduction in the acute care setting decreases hematoma expansion or improves outcomes in patients with deep ICH. ObjectiveTo determine whether intensive blood pressure reduction is associated with decreased risk of hematoma expansion and changes in 90-day modified Rankin Scale scores and if these associations are modified by the specific deep-brain nuclei involved. Design, Setting, and ParticipantsThis study is an exploratory analysis of the Antihypertensive Treatment of Acute Cerebral Hemorrhage-2 international, multicenter randomized clinical trial, which was conducted from May 2011 to September 2015, enrolled eligible patients with primary ICH, and followed up with them for 90 days. Patients who had ICH and complete neuroimaging data were included in the analysis. Data analysis was completed from July 2018 to December 2018. ExposuresParticipants were randomized to either intensive treatment (with a systolic blood pressure target of 110-139 mm Hg) or standard treatment (with a systolic blood pressure target of 140-179 mm Hg). Main Outcomes and MeasuresThe main outcome was hematoma expansion, defined as an increase greater than 33% in hematoma volume between baseline and 24 hours. Functional outcome was evaluated 90 days after the ICH via the modified Rankin Scale. ResultsOf 1000 trial participants, 870 (87.0%) had deep ICH, of whom 780 (89.7%) had complete neuroimaging data (of 336 thalamic and 444 basal ganglia hemorrhages). The baseline characteristics of the intensive and standard treatment groups remained balanced in this subgroup of the original study. Intensive treatment was associated with a decreased risk of hematoma expansion in univariable analysis (odds ratio [OR], 0.62 [95% CI, 0.43-0.87]; P=.006) and multivariable analysis (OR, 0.61 [95% CI, 0.42-0.88]; P=.009). This association was modified by the specific deep location of the ICH (OR, 0.44 [95% CI, 0.22-0.96]; interaction P=.02), with stratified analyses showing a reduction in risk of hematoma expansion with intensive vs standard treatment among basal ganglia ICH (OR, 0.44 [95% CI, 0.27-0.72]; P=.001) but not thalamic ICH (OR, 0.91 [95% CI, 0.51-0.64]; P=.76). Intensive treatment was not associated with an improvement in the modified Rankin Scale score distribution. Conclusions and RelevanceCompared with standard treatment, intensive blood pressure treatment was associated with reduced hematoma expansion in deep ICH, specifically among basal ganglia hemorrhages.