Volume and Location Analysis of Intracerebral Hemorrhage for the Appropriate Use of Andexanet Alfa

Andexanet alfa was approved as a reversal agent for Factor Xa inhibitors in patients with uncontrolled or life-threatening bleeding, such as intracerebral hemorrhage. However, its use in cases of small hemorrhages remains controversial. This study determined the appropriate use of andexanet alfa on the basis of hematoma volume and location analysis. The study included consecutive patients with intracerebral hemorrhage who took Factor Xa inhibitors between January 2020 and December 2024. Individuals receiving standard care (January 2020-June 2022) and those being administered andexanet alfa (July 2022-December 2024) were compared and classified by hematoma volume (<5 mL, 5-30 mL, and >30 mL). Sixty-one patients were enrolled, with 27 and 34 patients receiving standard care and andexanet alfa care, respectively.Excellent hemostasis (hematoma increase <20%) and preserved neurological findings (National Institutes of Health Stroke Scale change <4) were achieved in patients treated with andexanet alfa compared with patients who received standard care (p = 0.0007, p = 0.004). For middle-sized (5-30 mL) and large-sized (>30 mL) hematomas, the rate of patients with excellent hemostasis in andexanet alfa care was significantly higher than that of patients in standard care (p = 0.032, p = 0.035). Among small hematomas, those in the thalamus or brainstem were significantly associated with neurological deterioration due to hematoma expansion. Andexanet alfa prevented hematoma expansion in these regions of small hematomas (p = 0.0285). In conclusion, small hematomas located in deep regions such as the thalamus or brainstem and bigger than those in any location should be considered for treatment with andexanet alfa as a reversal agent of Factor Xa inhibitors.