Blood Type O Predicts Hematoma Expansion in Patients with Intracerebral Hemorrhage

Hematoma expansion after acute spontaneous intracerebral hemorrhage (ICH) is well established to result in poor prognosis. Recent studies have demonstrated that the ABO blood type system has potential implications on hemostatic properties. The purpose of this study was to explore the potential association of blood type O with hematoma expansion in patients with ICH and validate the usefulness in predicting early hematoma expansion.

We retrospectively enrolled consecutive patients with ICH who underwent baseline computed tomographic (CT) scan within 6 hours after onset of symptoms. The follow-up CT scan was available within 48 hours after the baseline CT scan. Hematoma expansion was defined as total volume increase more than 33% or more than 6 mL. We performed univariate and multivariate logistic regression analyses to investigate the relationship between the different types of blood (type O versus other types) and hematoma expansion.

A total of 210 patients were included in the study. Among them, 72 patients (34.3%) carried blood type O. Hematoma expansion was more common in patients with blood type O (41.7%) than those with other blood types (18.1%; P < .001). Furthermore, the time to baseline CT scan, blood type O, and admission Glasgow Coma Scale score were demonstrated to be independent predictors of hematoma expansion in multivariate logistic regression analysis model. The sensitivity, specificity, positive, and negative predictive values of blood type O for predicting hematoma expansion were 54.5%, 72.9%, 41.6%, and 81.9%, respectively.

Our findings suggest that blood type O represents an independent predictor of hematoma expansion after ICH. Hemostasis seems to be involved in expansion and may represent an important treatment target.