Location-Specific Hematoma Volume Cutoff and Clinical Outcomes in Intracerebral Hemorrhage

Abstract

Background: Major intracerebral hemorrhage (ICH) trials have largely been unable to demonstrate therapeutic benefit in improving functional outcomes. This may be partly due to the heterogeneity of ICH outcomes based on their location, where a small strategic ICH could be debilitating, thus confounding therapeutic effects. We aimed to determine the ideal hematoma volume cutoff for different ICH locations in predicting ICH outcomes.

Methods: We retrospectively analyzed consecutive ICH patients enrolled in the University of Hong Kong prospective stroke registry from January 2011 to December 2018. Patients with premorbid modified Rankin Scale score >2 or who underwent neurosurgical intervention were excluded. ICH volume cutoff, sensitivity, and specificity in predicting respective 6-month neurological outcomes (good [modified Rankin Scale score 0-2], poor [modified Rankin Scale score 4-6], and mortality) for specific ICH locations were determined using receiver operating characteristic curves. Separate multivariate logistic regression models were also conducted for each location-specific volume cutoff to determine whether these cutoffs were independently associated with respective outcomes.

Results: Among 533 ICHs, the volume cutoff for good outcome according to ICH location was 40.5 mL for lobar, 32.5 mL for putamen/external capsule, 5.5 mL for internal capsule/globus pallidus, 6.5 mL for thalamus, 17 mL for cerebellum, and 3 mL for brainstem. ICH smaller than the cutoff for all supratentorial sites had higher odds of good outcomes (all P<0.05). Volumes exceeding 48 mL for lobar, 41 mL for putamen/external capsule, 6 mL for internal capsule/globus pallidus, 9.5 mL for thalamus, 22 mL for cerebellum, and 7.5 mL for brainstem were at greater risk of poor outcomes (all P<0.05). Mortality risks were significantly higher for volumes that exceeded 89.5 mL for lobar, 42 mL for putamen/external capsule, and 21 mL for internal capsule/globus pallidus (all P<0.001). All receiver operating characteristic models for location-specific cutoffs had good discriminant values (area under the curve >0.8), except in predicting good outcome for cerebellum.

Conclusions: ICH outcomes differed with location-specific hematoma size. Location-specific volume cutoff should be considered in patient selection for ICH trials.

Keywords: cutoff; hematoma location; intracerebral hemorrhage; stroke outcome.

Figure 1.

Flow diagram of study inclusion and exclusion criteria. CT indicates computed tomography; ICH, intracerebral hemorrhage; and mRS, modified Rankin Scale.

Figure 2.

Location-specific hematoma volume cutoff and neurological outcome. The location-specific volume cutoff for predicting neurological outcomes of different intracerebral hemorrhage (ICH) locations are shown. Green represents good outcome (modified Rankin Scale [mRS] score 0–2), yellow represents poor outcome (mRS score 4–6), and mortality is colored red. The odds for good outcomes were significantly higher when ICH volumes were smaller than the location-specific cutoffs for all supratentorial ICH sites (all P<0.05). For poor outcome, the risk for all ICH locations was greater when volumes exceeded the respective cutoffs (all P<0.05). Mortality risks were also higher for volumes larger than cutoffs for lobar, putamen/external capsule (EC), internal capsule (IC)/globus pallidus (GP), and cerebellum (all P<0.001). *Multivariate regression analysis of respective outcome and location is available in Table S3. †Regression analysis cannot be performed as all brainstem ICH patients with volume >10.5 mL died at 6 mo.