Location-Specific Hematoma Volume Cutoffs for Predicting Functional Outcome and Mortality in Intracerebral Hemorrhage

Introduction: Outcomes after intracerebral hemorrhage (ICH) may be heterogeneous depending on the location. A small-volume ICH at particular sites could result in worse outcomes, thus using a single volume cutoff across all ICH locations may confound clinical prognostication and research trial findings. This study aimed to investigate the association between ICH location and outcomes and determine the optimal hematoma volume cutoffs for different ICH locations in predicting functional outcome and mortality.

Methods: We retrospectively analyzed consecutive ICH patients enrolled in the National University Hospital Spontaneous ICH Cohort from January 2014 to December 2020. Inclusion criteria were age ≥18 years, premorbid modified Rankin Scale (mRS) score 0–2, and spontaneous ICH not treated with surgical intervention. Patients with ICH at multiple locations, with recurrent ICH within 3 months, or without mRS data at 3 months after index ICH were excluded. ICH volume cutoffs for predicting poor functional outcome (mRS >2) and mortality at 3 months were derived for each ICH location using receiver operating characteristic analysis. Multivariate logistic regression was performed for the association of the respective volume cutoffs with outcomes. Cutoffs will be validated in a prospective validation cohort in the next phase of the study.

Results: 730 patients were included. For prognostication of functional outcome, the location-specific volume cutoffs were 23 mL for lobar, 11.5 mL for basal ganglia, 4 mL for thalamus, 15.5 mL for cerebellum, and 2.5 mL for brainstem (all p< 0.03). For predicting mortality risk, the location-specific volume cutoffs were 57 mL for lobar, 29.5 mL for basal ganglia, 12.5 mL for thalamus, 20 mL for cerebellum, and 2.5 mL for brainstem (all p< 0.01).

Conclusion : Hematoma volume thresholds for predicting functional outcome and mortality in ICH differed based on location. Location-specific ICH volume cutoffs may be incorporated in patient prognostication clinically and in patient selection for clinical trials.