Location‐Specific Hematoma Volume Tolerance for Spontaneous Intracerebral Hemorrhage: A Pooled Analysis of INTERACT2 and ATACH II

Background Location‐specific hematoma‐volume thresholds are potentially important for prognostication and surgical decisions in acute intracerebral hemorrhage. We aimed to define this metric in relation to poor functional outcome in a pooled individual patient‐level data analysis of 2 large intracerebral hemorrhage clinical trials: ATACH II (Antihypertensive Treatment of Acute Cerebral Hemorrhage) and INTERACT2 (Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial). Methods Final hematoma volumes were measured using planimetric analysis of 24‐hour computed tomography in relation to hematoma location stratified by basal ganglia, thalamus, and lobar regions. Volume thresholds in 5‐mL increments to >50 mL and Youden's index were used to identify optimal thresholds associated with poor outcome (modified Rankin Scale scores, 4–6) and death at 3 months. Multivariable logistic regression was used to estimate adjusted odds ratio models within each location. Results There were 1691 patients included in these analyses, with 919 (54.3%), 551 (32.6%), and 221 (13.1%) located in the basal ganglia, thalamus, and lobar regions, respectively. Using Youden's index, location‐specific hematoma volume thresholds (mL) that were most predictive of poor outcome were: 22.24 for basal ganglia (sensitivity, 0.57; specificity, 0.84; adjusted odds ratio, 4.82 95% CI, 3.19–7.27), 8.13 for thalamus (sensitivity, 0.68; specificity, 0.75; adjusted odds ratio, 2.73 95% CI, 1.62–4.59), and 21.99 for lobar (sensitivity, 0.82; specificity, 0.64; adjusted odds ratio, 6.31 95% CI, 2.53–15.74). Hematoma volume thresholds predictive of death were 19.72 for basal ganglia, 10.06 for thalamic, and 51.94 for lobar intracerebral hemorrhage. Conclusions Hematoma volumes associated with poor outcomes and death vary by anatomic location, indicating that each brain region has a distinct volume tolerance. Location‐specific volume thresholds may guide surgical intervention to reduce hematoma burden.