Patients who are taking anticoagulants are known to show poor outcomes for acute subdural hematoma. In cases of non–traumatic cerebral hemorrhage, patients with direct oral anticoagulants(DOAC) bleed less frequently and have less severe outcome than the patients with vitamin K antagonists (VKA). In this study, we reviewed 201 consecutive cases of acute subdural hematoma from April 2012 to March 2020 to demonstrate the difference of the outcome depending on the types of anticoagulants and the effect of neutralization.

Eighty–one cases (40.3%) had taken antithrombotic drugs. There were 37 cases (18.4%) taking anticoagulants, 54 cases (26.9%) taking antiplatelet drugs, and 10 cases taking both. The types of anticoagu­lants were VKA in 30 cases and DOAC in 7 cases. There were 19 patients taking VKA before approval of 4–factor prothrombin complex concentration (4F–PCC), 11 patients after approval and 8 patients of these were neutralized.

The good outcome for the cases without antithrombotic drugs was 59.2%, whereas that of cases without anticoagulants was 35.1%, sig­nificantly lower (chi–square test, p=0.010). It was 51.9% with anti­platelet drug.

Comparing the types of anticoagulant medications, the good out­comes were 26.7% in patients with warfarin and 71.4% with DOAC. There were significantly better with DOAC (Fisher’s exact tests, p=0.021).

Though 21,1% of the cases 4F–PCC approval had shown good out­come, the incidence turned to 36.4% after approval. The median PT–INR before administration of 4F–PCC was 2.49 (2.05 – 4.22), which was 1.09 (0.99 – 1.20) after administration.

DOAC should be selected over VKA to improve the outcome of acute subdural hematomas with anticoagulants. Vitamin K antagonist neu­trali­za­tion with 4F–PCC may improve outcomes. Further studies on the pathological conditions which are to be neutralized are needed.